# RS485/RS232/Serial transport class for mysensors.org

• @kimot Thank you for the information - your english is good enough to understand.

I'm just looking for more simple protocol than ethernet to send data from various places - wired.
And it seems that, for longer distance and cat5e cable in-wall, ethernet is the only choice

• @andriej
Just put CAT5e to every place (or even two CAT5e to each TV, room - as I done myself). Later you will decide what kind of signals will travel over CAT5e wire. It can be Ethernet or RS485, CANbus, or something else. Regular twisted pair Ethernet is also has a star topology with central hub/switch. (You may also remember an old Ethernet system with one base cable and terminating resistors on the both ends). For a really long distance - RS485 is the winner anyway - up to 1200m on slow speed.

• @LeoDesigner I will put cat5e for 'LAN' purposes to proper socket, but I also want to control my lights not via connecting/disconnecting 230V in-wall, but in central control panel.
I was planning to use doorbell push buttons on walls just to give signal to automation and then MCU will set proper relays/dimmers on/off etc.

That's why I was thinking about putting cat5e also to on-wall switches, then on 1 pair make the +/-12V signal, another pair for data bus etc. And now I'm looking for most efficient way to connect it everything together.
Each room will have temperature sensor for sure (in the switch), some may have dimmers etc. Last idea was to put mini arduinos inside the hole in wall, but I'm afraid of resetting them every once in a while, just because arduino likes to hang itself...

• @andriej remember to calculate how much current you can take thru cat5e and how much load there can be with one pair.
From wikipedia: "Maximum current per conductor 0.577A". So this would make P=UxI -> 12Vx0.577A=6.92W. There is calculations where one nano can take max 1.4Watts. You could use more wires of the car5e for power or lift voltage upper. 48Vx0.577A=27.70W

• @pjr I'm aware of that
Still struggling with decision either to use the CAT5e just as a loooong cable to (doorbell) switch or use it to PoE small nanos all over the place and run i.e. MQTT on each wall-switch separate.
In second option the RS485 protocol would be the best, because of small form factor (smaller than ethernet port inside switch) and possibility to use MySensors too

• @kimot what has to be done to prepare MySensors to use CAN?
I'm thinking about ordering some modules for tests.

• @andriej said:

use it to PoE small nanos all over the place

Which components do you have in mind? I 'm thinking in that direction too.

• @TimO this small W5100 module: http://www.aliexpress.com/item/TOP-Mini-W5100-LAN-Ethernet-Shield-Network-Module-board-Best/32457200047.html with step-down dc converter.
Cheaper than the PoE standard version.

### TOP Mini W5100 LAN Ethernet Shield Network Module board Be

\$5.45

• @andriej
It is a pity that not paying more attention mysensors.org for nodes interconnected by wires. But it is very difficult to find peer-to-peer protocol for RS485. Mainly because of solving collisions on the bus when multiple sensors. But it is very difficult to find peer-to-peer protocol for RS485. Mainly because of solving collisions on the bus when multiple sensors. I think that used ICSC library does not address this matter satisfactorily and with a larger number of sensor problems arise. ICSC library uses a Serial Software library by heavyweight each node on the bus, because all must be checke every bit transmitted on the bus. Look at different implementation:

www.mrbus.org

I think, thet using hardware UART is absolutely necessary.
Or why when we use a separate module for radio transmission, we use the special module for robust message transfer over the wired bus? CAN controllers are not so expensive in this days:

After correct CAN controller configuration, we simply write a message to the CAN controller and forgot about it. No check or bus arbitration. And through interrupt pin from the controller just pick up the incoming message with our ID or broadcast.

I know it's not as simple as using only RS485 transmitter itself, but we are guaranteed connecting maximum of 110 nodes and various libraries for Arduino for this CAN controller exist.

### MCP2515 CAN Bus Module Board TJA1050 receiver SPI For 51 MCU ARM controller M2

\$2.19
Sold out

• @andriej
But on the other side, with simply CANbus, we have got only 8 byte payload for our data.

• @kimot so the only thing that's left is TCP/IP and MQTT...

• @kimot
Thanks for pointing to mrbus.org.
I have seen this before - it's really nice implementation of RS485 bus management.
It's worth trying to implement it. However, I can see only one weak point of ICSC lib. It's a moment when both nodes listening a bus and starting to transmit at the same time. In this case the both packets will be lost. (This situation can occur only during the transmission of the first starting byte, so higher bus speed can make this situation rare.)
I have both the radio and wired mysensors network. And wired network in order of magnitude is more reliable. I have a really small amount of lost packets. The packets are retransmitted only due delay in the code of the nodes.

• HELP: Please instructions on how I can run this RS485 transport class for beginners.

Some basic questions:

1. First point instructions: File "SerialTransport.h" and "SerialTransport.cpp" download to C:\Program Files (x86)\Arduino\libraries\MySensors[here]. is this correct ?
2. On the second point instructions: "Add #include <SerialTransport.h> to your .ino sketch" but examples do not have this:
https://github.com/mysensors/Arduino/tree/development/libraries/MySensors/examples/MotionSensorRS485
https://github.com/mysensors/Arduino/tree/development/libraries/MySensors/examples/GatewaySerialRS485
way ?
In what file i must put this line "#include <SerialTransport.h>" ? main sketch ?
3. The third point instructions: Replace transport class with: "Replace transport class with: " where exactly ? Maybe I have a different version MySensors because I can not find the declaration "#define MY_RADIO_RF24" and replace it with a "#define MY_RS485". I do not know how to change the NRF to RS485 in lib MySensors. Please precise instructions with examples for the current version lib MySensors.
4. Can I get examples of sketch (confirmed that work with the physical bus RS485) Gateway and sensor.

I use Windows, path of arduino lib is: C:\Program Files (x86)\Arduino\libraries.

The only thing that works:
When I connect RS485 to USB on Raspberry Pi (domoticz) and on the other side sensor (Arduino Pro Mini + DHT22) received on Raspberry:

``````radek@raspberrypi \$ cat /dev/ttyUSB0
``````

It sent the sensor by the RS485 to Rasberry PI. So the RS485 is working properly.

Sorry for my English and thank you for your help.

• I think those instructions are written for older version of the library. Now you could just copy those examples and try without changing anything.... I think

• In the examples, there is no information on how to disable the radio NRF24 and enable RS485, this is my main problem.

MySensors still try init Radio NRF, because no radio connected in sending "radio init fail"

Renovate the house and so I want to use it:
Raspberry Pi (Domoticz) <--- USB ---> MySensor Gateway RS485 <--- RS485 (Cat5e) ---> MySensors Sensors & Actuators (x 20)

Will show photos when I finish.

In the examples, there is no information on how to disable the radio NRF24 and enable RS485, this is my main problem.

It is this line that activates the RS485 transport (also note that no radio is activated).
https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/examples/GatewaySerialRS485/GatewaySerialRS485.ino#L56

I haven't had the opportunity to test this thoroughly. So there might be issues.

• I think that constat value:

``````#define MY_RS485
``````

https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/examples/GatewaySerialRS485/GatewaySerialRS485.ino#L56

It is doing nothing and changes nothing. This constat value is only on exmaple sketch. It is not a reference to the constat value in the library MySensros and mysensors-serial-transport.

Searching 1628 files for "MY_RS485"
0 matches

??? I still do not know how to use the RS485 instead of NRF24 ???

• That's exactly what I looking for !. In my version of the library that are missing.
In my version of the library that (supports RS485) are missing.
I downloaded the Library https://github.com/mysensors/Arduino/archive/master.zip this is my problem.

The last question: Do I have just these two files download and replace from second url and that all ?

• You'll have to download replace everything in MySensors library folder.

HELP: Please instructions on how I can run this RS485 transport class for beginners.

You have to use a stable 1.5.2 version for my RS485 transport class. Not a development branch. You also may want to try development version too. The instruction was written for 1.5 (1.5.2) version of mysensors libs.

Some basic questions:

1. First point instructions: File "SerialTransport.h" and "SerialTransport.cpp" download to C:\Program Files (x86)\Arduino\libraries\MySensors[here]. is this correct ?

...\Arduino\libraries\SerialTransport\ [HERE]

1. On the second point instructions: "Add #include <SerialTransport.h> to your .ino sketch" but examples do not have this:
https://github.com/mysensors/Arduino/tree/development/libraries/MySensors/examples/MotionSensorRS485
https://github.com/mysensors/Arduino/tree/development/libraries/MySensors/examples/GatewaySerialRS485
way ?

They are for development version - not for stable 1.5.2

In what file i must put this line "#include <SerialTransport.h>" ? main sketch ?
Yes.

1. The third point instructions: Replace transport class with: "Replace transport class with: " where exactly ? Maybe I have a different version MySensors because I can not find the declaration "#define MY_RADIO_RF24" and replace it with a "#define MY_RS485". I do not know how to change the NRF to RS485 in lib MySensors. Please precise instructions with examples for the current version lib MySensors.

Please check examples for version 1.5 (1.5.2)

1. Can I get examples of sketch (confirmed that work with the physical bus RS485) Gateway and sensor.
``````/*
* MockMySensors 485
*
* This skecth is intended to crate fake sensors which register and respond to the controller
*
* Barduino 2015
*/

#include <MySigningNone.h>
//#include <MyTransportRFM69.h>
//#include <MyTransportNRF24.h>
#include <MyHwATMega328.h>
#include <MySigningAtsha204Soft.h>
#include <MySigningAtsha204.h>

#include <SPI.h>
#include <MySensor.h>
#include <MyMessage.h>

#include <SerialTransport.h>

#define RADIO_ERROR_LED_PIN 9  // Error led pin
#define RADIO_RX_LED_PIN    8  // Receive led pin
#define RADIO_TX_LED_PIN    7  // the PCB, on board LED

// Wait times
#define LONG_WAIT 500
#define SHORT_WAIT 50

#define SKETCH_NAME "FakeMySensors 485 241"
#define SKETCH_VERSION "v0.2"

// Global Vars
// unsigned long SLEEP_TIME = 60000; // Sleep time between reads (in milliseconds)
unsigned long SLEEP_TIME = 3000; // Sleep time between reads (in milliseconds)

boolean metric = true;
long randNumber;

// Instanciate MySersors Gateway
//MyTransportNRF24 transport(RF24_CE_PIN, RF24_CS_PIN, RF24_PA_LEVEL_GW);
//MyTransportRFM69 transport;
MyTransportSerial transport(Serial,241,6); // serial port, node, dePin (-1 disabled)

// Message signing driver (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
//MySigningNone signer;
//MySigningAtsha204Soft signer;
//MySigningAtsha204 signer;

// Hardware profile
MyHwATMega328 hw;

// Construct MySensors library (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
// To use LEDs blinking, uncomment WITH_LEDS_BLINKING in MyConfig.h
#else
MySensor gw(transport, hw /*, signer*/);
#endif

//Instanciate Messages objects

#ifdef ID_S_DOOR
MyMessage msg_S_DOOR(ID_S_DOOR,V_TRIPPED);
#endif

......
......
``````

I use Windows, path of arduino lib is: C:\Program Files (x86)\Arduino\libraries.

You have to decide which version of the library to use.
My SerialTransport is written only for version 1.5.2
It's tested and working. BTW, I will upload updated version in a few minutes to github.

• I still have a few questions:

1) Architecture: Do I understand correctly, example test:
raspberry pi domoticz [USB] <---- USB RS232 built-in Arduino nano ----> (hardware RS232, PIN: tx/rx) Arduino Nano (Gatwey RS485) (AltSoftSerial, PIN: 2,7,8) <---- RS485 AltSoftSerial ----> (AltSoftSerial, PIN: 2,7,8) Arduino Pro Mini <------ PIN 3, DHT22

2) Gatwey RS485 Arduino Nano:

• USB port of the Arduino Nano plugs in to Raspberry PI and set MySensors USB gateway in Domoticz ?
• Gatwaey to communicate with RS485 uses AltSoftSerial ? Whta PIN ? R0 / DI ?
• Gatwey Arduino Nano to communicate with Raspberry PI (Domoticz) use hardware USB (built in RS232) ?
• Gatweway don't have Debug mode (no free RS) ? When uploading have I must turn of debug mode in MyConfig.h when use RS485?
• DE PIN 2 ?
• RO PIN 8 ?
• DI PIN 9 ?
• PIN 2/8/9 connected directly without pull-up resistors or current limiting ?
``````  /**
...
* The gateway uses AltSoftSerial to handle two serial links
* on one Arduino. Use the following pins for RS485 link
*
*  Board          Transmit  Receive   PWM Unusable
* -----          --------  -------   ------------
* Teensy 3.0 & 3.1  21        20         22
* Teensy 2.0         9        10       (none)
* Teensy++ 2.0      25         4       26, 27
* Arduino Uno        9         8         10  <----- Form https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html .... (& other ATMEGA328)
* Arduino Leonardo   5        13       (none)
* Arduino Mega      46        48       44, 45
* Wiring-S           5         6          4
* Sanguino          13        14         12
*
*/

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enable RS485 transport layer
#define MY_RS485

// Define this to enables DE-pin management on defined pin
#define MY_RS485_DE_PIN 2

// Set RS485 baud rate to use
#define MY_RS485_BAUD_RATE 9600

// Enable serial gateway
#define MY_GATEWAY_SERIAL

// Flash leds on rx/tx/err
// Set blinking period

// Enable inclusion mode
//#define MY_INCLUSION_MODE_FEATURE
// Enable Inclusion mode button on gateway
//#define MY_INCLUSION_BUTTON_FEATURE
// Set inclusion mode duration (in seconds)
//#define MY_INCLUSION_MODE_DURATION 60
// Digital pin used for inclusion mode button
//#define MY_INCLUSION_MODE_BUTTON_PIN  3

#define MY_DEFAULT_ERR_LED_PIN 4  // Error led pin
#define MY_DEFAULT_RX_LED_PIN  5  // Receive led pin
#define MY_DEFAULT_TX_LED_PIN  6  // the PCB, on board LED

#include <SPI.h>
#include <MySensor.h>

void setup() {
// Setup locally attached sensors
}

void presentation() {
// Present locally attached sensors
}

void loop() {
// Send locally attached sensor data here
}

``````

3) Sensor Arduino Pro mini

• What uses to communicate with RS485 bus ? Hardware RS232 Pin RX /TX or AltSoftSerial Pin 2/7/8 ?
• If use AltSoftSerial: PIN 2/8/9 connected directly without pull-up resistors or current limiting ?
• When uploading have I must turn of debug mode in MyConfig.h when use RS485?
``````/**
...
// Enable RS485 transport layer
#define MY_RS485

// Define this to enables DE-pin manag ement on defined pin
#define MY_RS485_DE_PIN 2

// Set RS485 baud rate to use
#define MY_RS485_BAUD_RATE 9600

#include <SPI.h>
#include <MySensor.h>
#include <DHT.h>

#define MY_NODE_ID 15
#define CHILD_ID_HUM 0
#define CHILD_ID_TEMP 1
#define HUMIDITY_SENSOR_DIGITAL_PIN 3
unsigned long SLEEP_TIME = 2000; // Sleep time between reads (in milliseconds)

// Initialize sensors
DHT dht;
float lastTemp;
float lastHum;
boolean metric = true;
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);

// Debug
//#include <SoftwareSerial.h>
//SoftwareSerial mySerial(3, 4); // RX, TX

void setup()
{
//mySerial.begin(4800);
//mySerial.println("Hello, world?");
dht.setup(HUMIDITY_SENSOR_DIGITAL_PIN);
metric = getConfig().isMetric;
}

void presentation()  {
// Send the Sketch Version Information to the Gateway
sendSketchInfo("Falskiego LED salon", "1.0");

// Register all sensors to gw (they will be created as child devices)
present(CHILD_ID_HUM, S_HUM);
present(CHILD_ID_TEMP, S_TEMP);
}

void loop()
{
delay(dht.getMinimumSamplingPeriod());

// Fetch temperatures from DHT sensor
float temperature = dht.getTemperature();
if (isnan(temperature)) {
Serial.println("Failed reading temperature from DHT");
} else if (temperature != lastTemp) {
lastTemp = temperature;
if (!metric) {
temperature = dht.toFahrenheit(temperature);
}
send(msgTemp.set(temperature, 1));
#ifdef MY_DEBUG
Serial.print("T: ");
Serial.println(temperature);
#endif
}

// Fetch humidity from DHT sensor
float humidity = dht.getHumidity();
if (isnan(humidity)) {
Serial.println("Failed reading humidity from DHT");
} else if (humidity != lastHum) {
lastHum = humidity;
send(msgHum.set(humidity, 1));
#ifdef MY_DEBUG
Serial.print("H: ");
Serial.println(humidity);
#endif
}

sleep(SLEEP_TIME); //sleep a bit
}

``````

• This post is deleted!

• I made a test: did the system sends data from the sensor DHT22 to the rail 485 using only library AltSoftSerial and everything works properly. So the connection is ok.
I used the same libraries:

``````#include <AltSoftSerial.h>
``````

The same connections:
http://cmss.pl/arduino/MySensor_RS485_test02_a.JPG

A ) RS485 Gatwaey (arduino nano):
http://cmss.pl/arduino/MySensor_RS485_test02_b.JPG

``````#define MY_RS485_DE_PIN 2
``````

DE and RE -> Pin 2
RO -> Pin 8
DI -> Pin 9
Uploaded example MySensors Gatwey 485 and own code.

B ) RS485 Sensor DHT22 (arduino nano):
http://cmss.pl/arduino/MySensor_RS485_test02_c.JPG

``````#define MY_RS485_DE_PIN 2
``````

DE and RE -> Pin 2
RO -> Pin 8
DI -> Pin 9

Unfortunately, nothing works, no reaction, empty on debug console.

Any ideas what could be wrong, what to check ???

• Sorry to hear, I still haven't verified this so there might be problems.
It's this file that should be of interest:

https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/core/MyTransportRS485.cpp

Would be excellent if you had the time to debug it.

• @hek
Ok I will try.

• Hi I've tried a couple of months ago with success.
Maybe you have to connect also the GND cable each other.

Bye

• Hi,
I have tired similar configuration as radekzm.
2 x Arduino nano connected via RS485 and is looks like only rs485 is not working so my question is; How to verified that connection between to arduinos using library AltSoftSerial is ok ?

Are this connections PIN <-> RS485 (below) OK ?

DE and RE -> Pin 2
RO -> Pin 8
DI -> Pin 9

And below example is working fine (SoftwareSerial.h library)

https://arduino-info.wikispaces.com/SoftwareSerialRS485Example

• @Michal

I'll help when I get back from work.

• @LeoDesigner
I'm trying a Gateway & 4 relays/4 switches configuration using 1.5.2 version. As @Michal my configuration works fine with this example: https://arduino-info.wikispaces.com/SoftwareSerialRS485Example

Anything wrong with my sketches?

Gateway:

``````/**
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
* repeater and gateway builds a routing tables in EEPROM which keeps track of the
* network topology allowing messages to be routed to nodes.
*
* Copyright (C) 2013-2015 Sensnology AB
* Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
*
* Documentation: http://www.mysensors.org
* Support Forum: http://forum.mysensors.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
*******************************
*
* DESCRIPTION
* The ArduinoGateway prints data received from sensors on the serial link.
* The gateway accepts input on seral which will be sent out on radio network.
*
* The GW code is designed for Arduino Nano 328p / 16MHz
*
* Wire connections (OPTIONAL):
* - Inclusion button should be connected between digital pin 3 and GND
* - RX/TX/ERR leds need to be connected between +5V (anode) and digital pin 6/5/4 with resistor 270-330R in a series
*
* LEDs (OPTIONAL):
* - To use the feature, uncomment WITH_LEDS_BLINKING in MyConfig.h
* - RX (green) - blink fast on radio message recieved. In inclusion mode will blink fast only on presentation recieved
* - TX (yellow) - blink fast on radio message transmitted. In inclusion mode will blink slowly
* - ERR (red) - fast blink on error during transmission error or recieve crc error
*
*/

#define NO_PORTB_PINCHANGES

#include <MySigningNone.h>
#include <MyTransportRFM69.h>
//#include <MyTransportNRF24.h>
//#include <MyHwATMega328.h>
#include <MySigningAtsha204Soft.h>
#include <MySigningAtsha204.h>
#include <SerialTransport.h>

#include <SPI.h>
#include <MyParserSerial.h>
#include <MySensor.h>
#include <stdarg.h>
#include <PinChangeInt.h>
#include "GatewayUtil.h"

#define INCLUSION_MODE_TIME 1 // Number of minutes inclusion mode is enabled
#define INCLUSION_MODE_PIN  3 // Digital pin used for inclusion mode button
#define RADIO_ERROR_LED_PIN 4  // Error led pin
#define RADIO_RX_LED_PIN    6  // Receive led pin
#define RADIO_TX_LED_PIN    5  // the PCB, on board LED

// NRFRF24L01 radio driver (set low transmit power by default)
//MyTransportNRF24 transport(RF24_CE_PIN, RF24_CS_PIN, RF24_PA_LEVEL_GW);
//MyTransportRFM69 transport;
MyTransportSerial transport(Serial,AUTO,2);

// Message signing driver (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
//MySigningNone signer;
//MySigningAtsha204Soft signer;
//MySigningAtsha204 signer;

// Hardware profile
MyHwATMega328 hw;

// Construct MySensors library (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
// To use LEDs blinking, uncomment WITH_LEDS_BLINKING in MyConfig.h
#else
MySensor gw(transport, hw /*, signer*/);
#endif

char inputString[MAX_RECEIVE_LENGTH] = "";    // A string to hold incoming commands from serial/ethernet interface
int inputPos = 0;
boolean commandComplete = false;  // whether the string is complete

void parseAndSend(char *commandBuffer);

void output(const char *fmt, ... ) {
va_list args;
va_start (args, fmt );
vsnprintf_P(serialBuffer, MAX_SEND_LENGTH, fmt, args);
va_end (args);
Serial.print(serialBuffer);
}

void setup()
{
gw.begin(incomingMessage, 0, true, 0);

setupGateway(INCLUSION_MODE_PIN, INCLUSION_MODE_TIME, output);

// Add interrupt for inclusion button to pin
PCintPort::attachInterrupt(pinInclusion, startInclusionInterrupt, RISING);

// Send startup log message on serial
serial(PSTR("0;0;%d;0;%d;Gateway startup complete.\n"),  C_INTERNAL, I_GATEWAY_READY);
}

void loop()
{
gw.process();

checkButtonTriggeredInclusion();
checkInclusionFinished();

if (commandComplete) {
// A command wass issued from serial interface
// We will now try to send it to the actuator
parseAndSend(gw, inputString);
commandComplete = false;
inputPos = 0;
}
}

/*
SerialEvent occurs whenever a new data comes in the
hardware serial RX.  This routine is run between each
time loop() runs, so using delay inside loop can delay
response.  Multiple bytes of data may be available.
*/
void serialEvent() {
while (Serial.available()) {
// get the new byte:
char inChar = (char)Serial.read();
// if the incoming character is a newline, set a flag
// so the main loop can do something about it:
if (inputPos<MAX_RECEIVE_LENGTH-1 && !commandComplete) {
if (inChar == '\n') {
inputString[inputPos] = 0;
commandComplete = true;
} else {
// add it to the inputString:
inputString[inputPos] = inChar;
inputPos++;
}
} else {
// Incoming message too long. Throw away
inputPos = 0;
}
}
}

``````

4 relays / 4 switches

``````/*
State change detection (edge detection)

Often, you don't need to know the state of a digital input all the time,
but you just need to know when the input changes from one state to another.
For example, you want to know when a button goes from OFF to ON.  This is called
state change detection, or edge detection.

This example shows how to detect when a button or button changes from off to on
and on to off.

The circuit:
* pushbutton attached to pin 2 from +5V
* 10K resistor attached to pin 2 from ground
* LED attached from pin 13 to ground (or use the built-in LED on
most Arduino boards)

created  27 Sep 2005
modified 30 Aug 2011
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/ButtonStateChange

*/

#include <MySigningNone.h>
//#include <MyTransportNRF24.h>
//#include <MyTransportRFM69.h>
#include <SerialTransport.h>
#include <MyHwATMega328.h>
#include <MySensor.h>
#include <SPI.h>

// this constant won't change:
int buttonPin[] = {9, 10, 11, 12};          // array of pins that the pushbutton is attached to
int relayPin[] = {3, 4, 5, 6};           // array of pins that the relay is attached to
int pinCount = 4;                  // number of buttons/relays attached

// Variables will change:
int buttonState[] = {0, 0};         // current state of the button
int lastButtonState[] = {0, 0};     // previous state of the button

#define RELAY_ON 1
#define RELAY_OFF 0
int relayState[] = {RELAY_OFF, RELAY_OFF};   // counter for the number of button presses

// NRFRF24L01 radio driver (set low transmit power by default)
MyTransportSerial transport(Serial,AUTO,2);
// Message signing driver (none default)
//MySigningNone signer;
// Select AtMega328 hardware profile
MyHwATMega328 hw;
// Construct MySensors library
MySensor gw(transport, hw);

void setup()
{
// Initialize library and add callback for incoming messages
gw.begin(incomingMessage, AUTO, true);
// Send the sketch version information to the gateway and Controller
gw.sendSketchInfo("Relays & Buttons", "1.0");

for (int i = 0; i < pinCount; i++) {
// Register all sensors to gw (they will be created as child devices)
gw.present(buttonPin[i], S_LIGHT);
gw.present(relayPin[i], S_LIGHT);

// initialize the button pin as a input:
pinMode(buttonPin[i], INPUT);
digitalWrite(buttonPin[i], 0);
// initialize the relay as an output:
pinMode(relayPin[i], OUTPUT);
}
}

void loop() {
// Alway process incoming messages whenever possible
gw.process();

for (int i = 0; i < pinCount; i++) {
MyMessage msg(relayPin[i], V_LIGHT);

if (buttonState[i] != lastButtonState[i]) {
if (buttonState[i] == 1) {
//         gw.send(msg.set(relayState[i]==RELAY_ON ? RELAY_OFF : RELAY_ON));
//          if(relayState[i]==RELAY_ON) gw.send(msg.set(RELAY_OFF));
//          else                        gw.send(msg.set(RELAY_ON));
if(relayState[i]==RELAY_ON) relayState[i]=RELAY_OFF;
else                        relayState[i]=RELAY_ON;
}
lastButtonState[i] = buttonState[i];
}
digitalWrite(relayPin[i], relayState[i]);
}
}

void incomingMessage(const MyMessage &message) {
// We only expect one type of message from controller. But we better check anyway.
if (message.type==V_LIGHT) {
for (int i = 0; i < pinCount; i++) {
// digitalWrite(message.sensor-1+relayPin[1], message.getBool()?RELAY_ON:RELAY_OFF);
}
}
}

``````

• @elmarculino
In Gateway:

``````#include <MyTransportRFM69.h>
//#include <MyTransportNRF24.h>
//#include <MyHwATMega328.h>
...
MyTransportSerial transport(Serial,AUTO,2);

``````

Should be:

``````//#include <MyTransportRFM69.h>
//#include <MyTransportNRF24.h>
#include <MyHwATMega328.h>
....
MyTransportSerial transport(Serial,0,2);
``````

In 4relay / 4 switches:
Personally I am assigning a static ID to nodes, so I did not tested an AUTO option in gw.init. However I think this it should work. Also make sure you are downloaded a latest Serial transport class from github with some minor corrections.

• @LeoDesigner
Thanks for the help. I made the changes you pointed out, but still no lucky. What controller are you using? This should work in a direct crossover connection too?

• @elmarculino
I am using a custom controller based on the node-red, mqtt broker and homeassitant with mqtt bindings. But this is not essential - you can use 'nc GW_IP GW_PORT' from unix command line to issue commands to gateway directly. Try to separate your basic building blocks to smallest parts and then debug it.

• @LeoDesigner I still could not make it work in 1.5.2 with your library, but I will keep trying. Thanks!

@hek I finally could make a gateway / sensor (Humidity) connection via RS485 using the development branch. Is any Controller compatible with the development branch? Thanks!

``````0;255;3;0;9;Starting gateway (RSNGA-, 2.0.0-beta)
0;255;3;0;14;Gateway startup complete.
0;255;3;0;9;Init complete, id=0, parent=0, distance=0
1;0;1;0;1;44.0
1;0;1;0;1;43.0
1;0;1;0;1;44.0
1;1;1;0;0;27.0
``````

• Great to hear. Did you need to make any adjustments?

Yes, the serial protocol is backward compatible. So any controller should work as good.

• @hek None. Works out of the box. But I could not make it work with Home Assistant.

Pin 9 >>> DI
Pin 8 >>> RO
Pin 2 >>> DE and RE

``````INFO:mysensors.mysensors:/dev/ttyUSB0 is open...
INFO:mysensors.mysensors:Connected to /dev/ttyUSB0
INFO:mysensors.mysensors:n:0 c:255 t:3 s:9 p:read: 1-1-0 s=0,c=1,
WARNING:mysensors.mysensors:Error decoding message from gateway, probably received bad byte.
WARNING:mysensors.mysensors:Error decoding message from gateway, probably received bad byte.
WARNING:mysensors.mysensors:Error decoding message from gateway, probably received bad byte.`````````

• @LeoDesigner My 1.5.2 RS485 Humidity sensor send the same messages as the example Humidity sketch, but shows a lot of 'X' and '?' characters at 115200 in Serial Console.

The console with the example Humidity sketch is clean:

``````sensor started, id=1, parent=0, distance=1
send: 1-1-0-0 s=255,c=3,t=11,pt=0,l=8,sg=0,st=ok:Humidity
send: 1-1-0-0 s=255,c=3,t=12,pt=0,l=3,sg=0,st=ok:1.0
send: 1-1-0-0 s=0,c=0,t=7,pt=0,l=0,sg=0,st=ok:
send: 1-1-0-0 s=1,c=0,t=6,pt=0,l=0,sg=0,st=ok:
send: 1-1-0-0 s=1,c=1,t=0,pt=7,l=5,sg=0,st=ok:26.0
T: 26.00
send: 1-1-0-0 s=0,c=1,t=1,pt=7,l=5,sg=0,st=ok:44.0
H: 44.00
``````

Do you know what can be causing it? Am I doing anything wrong, again?

``````#include <SPI.h>
#include <MySensor.h>
#include <DHT.h>
#include <MyHwATMega328.h>
#include <SerialTransport.h>

#define CHILD_ID_HUM 0
#define CHILD_ID_TEMP 1
#define HUMIDITY_SENSOR_DIGITAL_PIN 3
unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)

MyTransportSerial transport(Serial,5,2);
MyHwATMega328 hw;
MySensor gw(transport, hw);
DHT dht;
float lastTemp;
float lastHum;
boolean metric = true;
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);

void setup()
{
gw.begin();
dht.setup(HUMIDITY_SENSOR_DIGITAL_PIN);

// Send the Sketch Version Information to the Gateway
gw.sendSketchInfo("Humidity", "1.0");

// Register all sensors to gw (they will be created as child devices)
gw.present(CHILD_ID_HUM, S_HUM);
gw.present(CHILD_ID_TEMP, S_TEMP);

metric = gw.getConfig().isMetric;
}

void loop()
{
delay(dht.getMinimumSamplingPeriod());

float temperature = dht.getTemperature();
if (isnan(temperature)) {
Serial.println("Failed reading temperature from DHT");
} else if (temperature != lastTemp) {
lastTemp = temperature;
if (!metric) {
temperature = dht.toFahrenheit(temperature);
}
gw.send(msgTemp.set(temperature, 1));
Serial.print("T: ");
Serial.println(temperature);
}

float humidity = dht.getHumidity();
if (isnan(humidity)) {
Serial.println("Failed reading humidity from DHT");
} else if (humidity != lastHum) {
lastHum = humidity;
gw.send(msgHum.set(humidity, 1));
Serial.print("H: ");
Serial.println(humidity);
}

gw.sleep(SLEEP_TIME); //sleep a bit
}
``````

• @elmarculino
My library is using a standard hardware serial port of arduino - you have to disable debug option in MySensors config and use the serial port only for RS485. The 'garbage' you are receiving are actual binary communication packets intended only for RS485 bus. You have to disconnect your serial to usb adapter in case if you are using Arduino Pro. Please take a closer look to the video and schematic coming with the library. You can use and 'sniff' your serial console - but you must to disable any additional serial debug prints to the console in production mode. Remember - your serial console is a RS485 bus with this library.

OK, what I did:
on one Arduino nano I have this sketch
https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/examples/GatewaySerialRS485/GatewaySerialRS485.ino
on second arduino nano I have conbined two sketches:
https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/examples/DistanceSensor/DistanceSensor.ino
and
https://github.com/mysensors/Arduino/blob/development/libraries/MySensors/examples/MotionSensorRS485/MotionSensorRS485.ino
and the results is:

``````/**
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
* repeater and gateway builds a routing tables in EEPROM which keeps track of the
* network topology allowing messages to be routed to nodes.
*
* Copyright (C) 2013-2015 Sensnology AB
* Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
*
* Documentation: http://www.mysensors.org
* Support Forum: http://forum.mysensors.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
*******************************
*
* REVISION HISTORY
* Version 1.0 - Henrik Ekblad
*
* DESCRIPTION
* This is an example of sensors using RS485 as transport layer
*
* Motion Sensor example using HC-SR501
* http://www.mysensors.org/build/motion
*
* The transport uses AltSoftSerial to handle two serial links
* on one Arduino. Use the following pins for RS485 link
*
*  Board          Transmit  Receive   PWM Unusable
* -----          --------  -------   ------------
* Teensy 3.0 & 3.1  21        20         22
* Teensy 2.0         9        10       (none)
* Teensy++ 2.0      25         4       26, 27
* Arduino Uno        9         8         10
* Arduino Leonardo   5        13       (none)
* Arduino Mega      46        48       44, 45
* Wiring-S           5         6          4
* Sanguino          13        14         12 *
*
*/

// Enable RS485 transport layer
#define MY_RS485

// Define this to enables DE-pin management on defined pin
#define MY_RS485_DE_PIN 2

// Set RS485 baud rate to use
#define MY_RS485_BAUD_RATE 9600

#include <SPI.h>
#include <MySensor.h>
#include <NewPing.h>

#define CHILD_ID 1
#define TRIGGER_PIN  5  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     6  // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 300 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.
unsigned long SLEEP_TIME = 5000; // Sleep time between reads (in milliseconds)

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.
MyMessage msg(CHILD_ID, V_DISTANCE);
int lastDist;
boolean metric = true;

void setup()
{
metric = getConfig().isMetric;
}

void presentation() {
// Send the sketch version information to the gateway and Controller
sendSketchInfo("Distance Sensor", "1.0");

// Register all sensors to gw (they will be created as child devices)
present(CHILD_ID, S_DISTANCE);
}

void loop()
{
int dist = metric?sonar.ping_cm():sonar.ping_in();
Serial.print("Ping: ");
Serial.print(dist); // Convert ping time to distance in cm and print result (0 = outside set distance range)
Serial.println(metric?" cm":" in");

if (dist != lastDist) {
send(msg.set(dist));
lastDist = dist;
}

sleep(SLEEP_TIME);
}
``````

On serial port (/dev/ttyUSB0) Controller (first nano) I see:
0;255;3;0;9;Starting gateway (RSNGA-, 2.0.0-beta)
0;255;3;0;14;Gateway startup complete.
0;255;3;0;9;Init complete, id=0, parent=0, distance=0

on serial port(/dev/ttyUSB1) in node is see:
...
Ping: 33 cm
Ping: 34 cm
Ping: 34 cm
Ping: 33 cm
Ping: 33 cm
Ping: 33 cm
Ping: 5 cm
Ping: 91 cm
Ping: 88 cm
Ping: 89 cm
......

But I expect to see some message on controller. What can I check? Do you see and mistakes ?

• Hi,
I am new in mysensors and arduino however I already use domoticz with mysensors and rflink.
Everything is working fine however now I plan to renovate my house and I would like to put wire connection using max485 and arduino. Problem is that it is now working I have tried 1.5.4 version and also development branch. It seems that signal is not getting to gateway. I nothing see on arduino gateway except of initalization gateway. I have started to use two nano but I also tried combination nano and mega without success. I would be very appreciate if someone who done it could more describe how to make that it works.
I tried https://arduino-info.wikispaces.com/SoftwareSerialRS485Example and it works fine.
I use for nano combination pins 2 (de/re), 8 (ro),9(di)

• @Mariusz jak jesteÅ› Polakiem ? JeÅ¼eli tak to mogÄ™ Ci pomÃ³c po polsku bÄ™dzie Å‚atwiej

• @radekzm Please use private chat/PM if you don't intend everyone to read it.

• @m26872
I'm sorry and promises to improve

@Mariusz
In my case the solution was in MyConfig.h file (in my case C:\Program Files (x86)\Arduino\libraries\MySensors):

1. Disable function MY_DISABLED_SERIAL
commenting lines 49
// #define MY_DISABLED_SERIAL

2. Disable function MY_DEBUG
commenting lines 36
//#define MY_DEBUG

3. Correct connection is on my pictures enclosed in the above comment

Board | Transmit | Receive | PWM Unusable
Arduino Uno | 9 | 8 | 10 <----- Form https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html .... (& other ATMEGA328)
Arduino Leonardo | 5 | 13 | (none)
Arduino Mega | 46 | 48 | 44, 45

DE and RE -> Pin 2
RO -> Pin 8
DI -> Pin 9

1. To check the hardware and connections run the "Example Program" from https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html

2. Use development branch

• @LeoDesigner
Hi, I am trying to do almost the same, but I would like to use softwareSerial instead of altsoft. The reason why I would do this is that i can barely fit the arduino nano inside my case, and an additional rs485 module would not fit and that I have 8 nodes connected on the softwareserial . I have tested software serial on arduino and it seems to work fine up to 15meters, I also adjusted the baudrate to 9600 since my node does not send out/receive large amount of data. I read that you did some work on software serial and were wondering if you could take a look at this thread.

• Is there any how-to's on this transport class as far as the hardware goes? How does it work with multiple nodes? Is it like a ring pattern? or do all the nodes have to have a dedicated connection to the gateway.

• Depends on your physical transport layer. I would say a multidrop link where everything is in parallel..

• Is it possible, to built a esp8266 wifi gateway and communicate GW to node with rs485?
In altsoft esp8266 is not decleared, so i can't use it out of the box.

Btw: I tested my_rs485 with nano as GW and Pro Mini as node, and it worked great. Thank you

• @hausinger I don't think so. I haven't heard of anyone trying. I guess you'd have to replace alt-soft-serial with something else.

• @hausinger if you know about coding..

• Hi,

Any reason why this lib is not using Serial1 or Serial2 on Arduino Mega 2560 instead of AltSoftSerial?

• @Bartek-Celary
No, not really. Just that not many that uses 2560.

• How about adding the following define to use the Serial1/2 on Mega. I have not tested yet but assuming the AltSoftSerial lib has the same interface/functionality it should work.

``````#define MY_RS485_SERIAL Serial1
``````
``````diff --git a/core/MyTransportRS485.cpp b/core/MyTransportRS485.cpp
index 814f721..ea35c9e 100644
--- a/core/MyTransportRS485.cpp
+++ b/core/MyTransportRS485.cpp
@@ -92,7 +92,11 @@ unsigned char _recSender;
unsigned char _recCS;
unsigned char _recCalcCS;

+#if defined(MY_RS485_SERIAL)
+HardwareSerial& _dev = MY_RS485_SERIAL;
+#else
AltSoftSerial _dev;
+#endif

unsigned char _nodeId;
``````

• Looks like a neat solution. If it verifies ok, please create a pull request agains the development branch.

• I understand that the RS485 is a separate gateway to communicate. Is it also possible to have the wireless gateway and RS485 gateway combined?

• Currently, no..

• @hek Thanks for the quick response. I'm looking for some direction (this might not be the right forum).
I want to create a node to control my Itho Ecofan ventilation box. I now have a working program (thanks to the help of Rogier Reedijk The nodo now uses a CC1101 transceiver to control the box and thus uses the SPI bus. I'm looking for some direction to use this transmitter as part of my sensor network so I can control it from my Domoticz. Hope you can give me some directions how to proceed.

• Why do you need to hook it up to RS485 wired network? Can't you just forwards commands to the CC11001 from any radio node or the gateway?

• Is it then possible to use the two radio's on one node and share the SPI bus?

• Yes, if the CC11001 behaves correctly.

• Thanks, will try that

• Hello,
I have a problem running gatewayserial to rs-485 and the node with the usual lightsensor.
NODE # 1 as a gateway and tried to upload a sketch of the library 2.0 and 1.5.4, and the monitor serial I can not see any data, I use to check on the serial PuTTy com6 because the converter rs-485 to USB is connected to the PC.

NODE # 2 as a light sensor, during the upload Sketch by arduino programmer for serial monitor can see the data being sent but after plugging arduino to rs-485 as below no longer visible.

My question is whether I have something wrong with the connection or sketch, can someone show an example of a complete sketch for the gateway, and a node?

Connection mine looks like this:
TX and RX Connect was to pins 0 and 1 in arduino or 8 and 9, DE is always PIN 2.

• Looks like you got the pins to the Arduino wrong.

Pin 9 >>> DI
Pin 8 >>> RO
Pin 2 >>> DE and RE

• I need a nice picture done in fritzing (or similar) for an article on the main site on how to connect the RS485 module (atmega 328 enough I guess).

Anyone volunteering in making one?

• so this is a 1 to 1 setup right? There is nothing here for multiple serial nodes correct?

• Aren't they just daisy chained?

• @hek
On the pictures is connect to TX and RX pins arduino but I tried to connect to pins 8,9,2 and result was the same
On thsi connections with pins 8,9,2 ofcourse and library mysensors 2.0 should works fine ?

• Yes, people have reported the RS485 transport working above.

I just created this article with a summary of this thread
https://www.mysensors.org/build/rs485

• @elektro12345

So what's with the DE+RE pins on that USB-RS485 converter? Will it even work in this configuration? I do have such converter but so far I've used the arduino as a SerialGateway to connect to RPi.

• I am not sure if I am seeing a normal behavior. I don't know if it is expected that the sensor is taking such long time to become visible to the GW. I have recreated the examples from https://www.mysensors.org/build/rs485

The only difference is that I've added SketchInfo for the GW and used Serial1 on MEGA board instead of AltSoftSerial.

The debug on the motion sensor is as follows:

``````MCO:BGN:INIT NODE,CP=RSNNA--,VER=2.0.1-beta
TSM:INIT
TSM:INIT:TSP OK
TSF:ASID:OK,ID=1
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
!TSM:FPAR:FAIL
TSM:FAILURE
TSM:FAILURE:PDT
TSM:FAILURE:RE-INIT
TSM:INIT
TSM:INIT:TSP OK
TSF:ASID:OK,ID=1
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSF:MSG:FPAR RES,ID=0,D=0
TSF:MSG:FPAR OK,ID=0,D=1
TSM:FPAR:OK
TSM:ID
TSM:ID:OK,ID=1
TSM:UPL
TSF:PING:SEND,TO=0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
TSF:CHKUPL:FAIL
!TSM:UPL:FAIL
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSF:MSG:FPAR RES,ID=0,D=0
TSF:MSG:FPAR OK,ID=0,D=1
TSM:FPAR:OK
TSM:ID
TSM:ID:OK,ID=1
TSM:UPL
TSF:PING:SEND,TO=0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
TSF:CHKUPL:FAIL
!TSM:UPL:FAIL
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSF:MSG:FPAR RES,ID=0,D=0
TSF:MSG:FPAR OK,ID=0,D=1
TSM:FPAR:OK
TSM:ID
TSM:ID:OK,ID=1
TSM:UPL
TSF:PING:SEND,TO=0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
TSF:CHKUPL:FAIL
!TSM:UPL:FAIL
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSF:MSG:FPAR RES,ID=0,D=0
TSF:MSG:FPAR OK,ID=0,D=1
TSM:FPAR:OK
TSM:ID
TSM:ID:OK,ID=1
TSM:UPL
TSF:PING:SEND,TO=0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
TSF:CHKUPL:FAIL
!TSM:UPL:FAIL
TSM:FPAR
TSF:MSG:SEND,1-1-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSF:MSG:FPAR RES,ID=0,D=0
TSF:MSG:FPAR OK,ID=0,D=1
TSM:FPAR:OK
TSM:ID
TSM:ID:OK,ID=1
TSM:UPL
TSF:PING:SEND,TO=0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
TSF:MSG:PONG RECV,HP=1
TSF:CHKUPL:OK
TSM:UPL:OK
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0100
TSF:MSG:SEND,1-1-0-0,s=255,c=0,t=17,pt=0,l=10,sg=0,ft=0,st=OK:2.0.1-beta
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=6,pt=1,l=1,sg=0,ft=0,st=OK:0
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=11,pt=0,l=13,sg=0,ft=0,st=OK:Motion Sensor
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=12,pt=0,l=3,sg=0,ft=0,st=OK:1.0
TSF:MSG:SEND,1-1-0-0,s=1,c=0,t=1,pt=0,l=0,sg=0,ft=0,st=OK:
MCO:REG:REQ
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
TSF:MSG:SEND,1-1-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
MCO:PIM:NODE REG=1
MCO:BGN:STP
MCO:BGN:INIT OK,ID=1,PAR=0,DIS=1,REG=1
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
0
TSF:MSG:SEND,1-1-0-0,s=1,c=1,t=16,pt=0,l=1,sg=0,ft=0,st=OK:0
``````

I don't know how to obtain debug from the Gateway Serial but as far as the GW messages on the console it looked as follows:

``````0;255;3;0;14;Gateway startup complete.
0;255;0;0;18;2.0.1-beta
0;255;3;0;11;SerialGateway
0;255;3;0;12;0.1
1;255;3;0;6;0
1;255;3;0;11;Motion Sensor
1;255;3;0;12;1.0
1;1;0;0;1;
1;1;1;0;16;0
1;1;1;0;16;0
1;1;1;0;16;0
1;1;1;0;16;0
1;1;1;0;16;0
``````

As you see it takes a fair amount of time (around 30-40 secs) to obtain the readings from the sensor. This happens each time I reset the sensor node but it works instantly if I reset the GW (i.e. the readings appear instantly after the reset). Is it expected behavior?

• 30 seconds sound like a long time.. Not sure what could be wrong. I don't have any test setup here unfortunately.

• Hi,
I am wondering if I can just use the mySensors Lib to pass on the data via another connection. Currently I have a Loxone Controller which accepts UDP and TCP/IP connections (and others, but I chose these). As gateway I have an ArduinoMega and the network is running on RS485.
So my understanding is that I can setup the network with the mySensors code and all the data is collected by the gateway which passes the data via UDP to the controller. V.v. the controller sends the data to the gateway which passes tha data on to the correspondent node.
Is there any project similar to this?
Thank you very much for your help!
Best regards Kduino

• @Bart I do not know what You mean with DE+RE pins on the converter.
On the converter You connect A and B calbe from bus.
DE and RE pins fromMAX485 You connect with sealf and connect to pin in my case D2 on Arduino.

• I have a question, when I wont send do domoticz from Arduino presentation lightsensor I can send by serial something like this:

``````1;2;0;0;16;V_LIGHT_LEVEL
``````

and domoticz will understend that is the lightsensor LUX ?

• @hek

I was able to solve that long initialization problem with removing AltSoftSerial completely and using another Mega board on Serial1 serving as a GW. It looks like the AltSoftSerial on Nano was not working well with Serial1 on Mega.

Strange that although now it works almost instantly, the reading of data from the HA takes longer than before... Not sure what could be causing this.

It looks that these RS485 modules have the resistors already added between A and B cables and +5 and GND so I don't think that could be an issue.

• Thanks for the feedback.

So how should the modules be inter-connected? Do you have time to create some drawing for the instruction page?

• @hek
I will do the schematic once I solve all issues as I am still losing events while connected to Home Assistant. Need to check whether it is because of pymysensors library (Home Assistant side) or if there is still some GW <-> Sensors problem. At this moment my Sensors board has around 48 binary states one can set/read from the controller and at the same time they are changeable via input pins (falling edge toggles the switch).

To give a quick overview of my setup:

2 x (MEGA 2560 + RS485 module)

I have the following connections for each mega+rs485 module:

• +5/GND connected to respective pins on rs485 module
• D2 connected to RE/DE
• D18 <-> RO
• D19 <-> DI

The A and B lines are connected to each other. (A-A, B-B). And most importantly I am using the above mentioned minor change in the MyTransportRS485.cpp to replace altSoftSerial with Serial1 (https://forum.mysensors.org/topic/1947/rs485-rs232-serial-transport-class-for-mysensors-org/99)

and just if anyone would like to try it here's the config I am using:

``````// Gateway:
#define MY_RS485
#define MY_RS485_DE_PIN 2
#define MY_RS485_BAUD_RATE 9600
#define MY_GATEWAY_SERIAL
// below not official for getting the Serial1
#define MY_RS485_SERIAL Serial1
``````
``````// Sensor node
#define MY_DEBUG
#define MY_RS485
#define MY_RS485_DE_PIN 2
#define MY_RS485_BAUD_RATE 9600
// below not official for getting the Serial1
#define MY_RS485_SERIAL Serial1
``````

• @Bart
Does it work with serial1 on mega2560?

I can't get a single bit out of the harware serial1.
Is it only the smal patch in MyTransportRS485.cpp?

• @karlheinz2000
Yes. Got it working with this patch. Although not reliably when other board was using the altsoftserial.

• Got it working too
Problem was: RX1 and TX1 labels on the chinese Mega2560 board are swapped.
All other RX/TX labels are right.

• @karlheinz2000 Are any of your boards using AltSoftSerial instead of HW serial? I was not able to get a reliable connection with software serial library....

• I use a mega with hw-serial and a nano (gateway) with AltSoftSerial.
It works fine the last 24 hours. Still running...
I did not test other configurations.

• @hek Looks like something has been fixed in regards to altSoftSerial. Today I've pulled latest development and everything works fine. The gateway has no problem finding nodes and all messages reach their destinations.

• Hmm, strange. Wonder if this PR affected the behaviour of AltSoftSerial (in a good way).

https://github.com/mysensors/MySensors/pull/599

Yveaux created this issue in mysensors/MySensors

### closedFix detach pin interrupt in hwSleep#599

• @hek I will try to check if this change did it.

• I am wondering if a node-2-node communication should be working. I have compiled the ping/pong example for RS485 but it appears the nodes are not communicating.

• Did you set one of them to be repeater (or gateway)?

• @hek ok. all good now - the ping pong example working. I forgot about the gateway flag.

BTW, checked to see if the GW has any issues without PR 599 but it seems it is still working OK. I have not changed the HW connections so must be some other change.

• Is any data buffer/FIFO implemented in RS485 gateway?
My controller (fhem) is transmitting data too fast to the gateway, so some data is not transmitted on RS485.
I checked RX/TX from controller to gateway -> all data is going into gateway. But not all data goes out to my sensor node.

I have only one sensor (and gateway) on RS485.
Baudrate is 19200 on RS485 and to controller.
Sensor node uses HW serial. Gateway is on NANO with AltSoftSerial.

• @karlheinz2000
I had no chance to look to the AltSoftSerial code, but if we are talking about hardware serial - arduino as a standard has 64 bytes buffer. I think it's possible that your gateway is not fast enough to process packets at high rate from FHEM. Also even if they are processed on time - at 19200 you may loose packets due low serial speed. It's simple no room for next packet.

• @LeoDesigner
I did a hardware update. Now sensor and gateway are arduino mega. Everything is running on 115200 hardware serial.
RS485 communication looks good. Data is going into sensor node, but does not appear in MySensors.
I tried to increase RX buffer via #define SERIAL_RX_BUFFER_SIZE 256, with no effect in functionality. Does this define works as expected? Because this buffer size number has no effect on the 'dynamic memory' usage after compiling the sketch. It shows always the same number of used bytes, independent of the RX buffer size.

• [Solved]
Initial Problem were incoming messages at sensor node during reading an image from SD card (170ms). Increase of serial RX buffer size solved the problem.

Good to know:
The serial buffer size is not defined in:
c:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino\HardwareSerial.h
You can change the numbers with no effect to your sketch.

You have to change:
c:\Users...\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.14\cores\arduino\HardwareSerial.h

Then it will work

• I'm curious whether it is possible to use this RS485 transport with Ethernet or MQTT gateway or Serial gateway is the only option?
For example, controller talks with MySensors Gateway over Ethernet,
MySensors Gateway talks with the Nodes over RS485.
Thanks!

• @AndrewZ

Yes, that should work just fine.

• @hek
thanks for this really fast and motivating response, I will try!

• I'm trying to get my Ethernet gateway (UNO with W5100) working with RS485 transport.
While RS485 part seems to be working fine between the node and gateway, the Ethernet part seems to be dead. I suspect this is related to the fact that Ethernet shield uses pin 10 which is unusable with RS485. Am I right? Any workaround?

• Today the new rs485 shield arrived, i will solder it up over the weekend and start testing early next week:)