RS485/RS232/Serial transport class for mysensors.org

[skatun]

@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.

[CrankyCoder]

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.

[tbowmo]

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

[hausinger]

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 :)

[hek]

@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.

[scalz]

@hausinger if you know about coding..

• plain C lib for esp8266, it can be adapted to work with Arduino Esp: https://github.com/plieningerweb/esp8266-software-uart
• or use stock arduino esp8266 software serial lib (https://github.com/plerup/espsoftwareserial), and inspire yourself from lib above, and code your CE pin management..

[Bart]

Hi,

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

[hek]

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

[Bart]

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;

[hek]

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

[lan]

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

[hek]

Currently, no..

[lan]

@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.

[hek]

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?

[lan]

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

[hek]

Yes, if the CC11001 behaves correctly.

[lan]

Thanks, will try that

[elektro12345]

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.

[hek]

Looks like you got the pins to the Arduino wrong.

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

[hek]

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?