Today I came across interesting project https://github.com/nerdralph/ArduinoShrink that promises smaller and faster code for ATmega168 and 328 MCUs at 4 to 16 MHZ.

But the library is not compatible with mysensors

wiring.c.o (symbol from plugin): In function `delayMicroseconds':
(.text+0x0): multiple definition of `main'
sketch/mys-868-node.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here
collect2: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino Pro or Pro Mini.

Would it be possible to make it compatible? Is the problem maybe in the know limitation that when the pin is not known at compile time?

@Gilles-BILLARD Damn! Why did I order UNO if I could use another Pro Mini for programming... :)

In case someone is interested in the code for mysensors mqtt gateway using the DS2482.h library from https://github.com/paeaetech/paeae. The temperature conversion code is from example. I am omitting the mysensors setup.

...

#include <DS2482.h>
#include <Ethernet.h>
#include <MySensors.h>
#include <Wire.h>


DS2482 ds( 0 );  //channels ds2482-800 is 0 to 7, DS2482-100 is just set 0
byte dsData[8]; //holding for onewire capture
byte dsAddr[8]; //1wire wire address and CRC

MyMessage msgAddr( 0, V_ID );
MyMessage msgTemp( 0, V_TEMP );


void setup() {

  //Uses Wire library to communicate with DS2482 so be sure to call Wire.begin() before using the library.
  Wire.begin();
  ds.reset();

}

void presentation() {

  // Send the sketch version information to the gateway and Controller
  sendSketchInfo( SKETCH_NAME, SKETCH_MAJOR_VER "." SKETCH_MINOR_VER );

}

void loop() {

  #ifdef MY_DEBUG
    Serial.println( "DBG: loop start" );
  #endif

  ds.wireResetSearch();
  ds.wireReset();
  ds.wireSkip();
  //need to send high power to bus??  Adding 5 volts to devices makes it work.
  ds.wireWriteByte( 0x44 ); //convert temperature on all devices
  delay( 1000 );

  byte sensorId = 0;
  while( ds.wireSearch( dsAddr ) ) {

    #ifdef MY_DEBUG
      Serial.print( sensorId );
      Serial.print( " : " );
    #endif

    char sensorAddr[17]; //eg. 280838211713012D

    for( int i = 0; i < 8; i++ ) {
      
      sensorAddr[i*2] = ( dsAddr[i] >> 4 ) + 0x30;
      if ( sensorAddr[i*2] > 0x39 ) {
        sensorAddr[i*2] += 7;
      }
      
      sensorAddr[i*2+1] = ( dsAddr[i] & 0x0f ) + 0x30;
      if ( sensorAddr[i*2+1] > 0x39 ) {
        sensorAddr[i*2+1] += 7;
      }

    }

    sensorAddr[16]  = '\0'; //always zero terminate string
    
    #ifdef MY_DEBUG
      Serial.print( sensorAddr );
      Serial.print( "\n" );
    #endif

    send( msgAddr.setSensor( sensorId ).set( sensorAddr ) );

    #ifdef MY_DEBUG
      Serial.print( sensorId );
      Serial.print( " : " );
    #endif

    if ( ds.crc8( dsAddr, 7 ) != dsAddr[7] ) {
      Serial.print( "CRC is not valid!" );
      return;
    }

    /*
    //test if device code DS18B20
    if ( dsAddr[0]==0x28 ) {

    //test if device code MAX31850
    if ( dsAddr[0]==0x3B ) {
    */

    //read temperature data.
    ds.wireReset(); //ds.reset();
    ds.selectChannel( 0 ); //necessary on -800
    ds.wireSelect( dsAddr );
    ds.wireWriteByte( 0xbe ); // Read Scratchpad command

    //display hex values of scratchpad
    for ( int i = 0; i < 9; i++ ) { // we need 9 bytes
      dsData[i] = ds.wireReadByte();

      #ifdef MY_DEBUG
        if ( dsData[i] < 16 ) {
          Serial.print( "0" );
        }
        Serial.print( dsData[i], HEX );
      #endif
    }
    
    //convert to decimal temperature
    int LowByte = dsData[0];
    int HighByte = dsData[1];
    int TReading = ( HighByte << 8 ) + LowByte;
    int SignBit = TReading & 0x8000; // test most sig bit
    if ( SignBit ) // negative
    {
            TReading = ( TReading ^ 0xffff ) + 1; // 2's comp
    }

    float Tc_100 = (double) TReading * 0.0625;

    if ( SignBit ) { // If its negative
            Tc_100 = 0 - Tc_100;
    }

    //print temp for each device
    #ifdef MY_DEBUG
      Serial.print( " : " );
      Serial.println( Tc_100 );
    #endif

    send ( msgTemp.setSensor( sensorId ).set( Tc_100, 2 ) );

    sensorId++;
  }

  #ifdef MY_DEBUG
    Serial.println( "DBG: loop end" );
  #endif

  delay( 60000 );
}

I am of course happy for any feedback. Especially if I am doing anything stupid as I am no programmer :)

@zboblamont Thanks for the tip. I am trying to avoid hardcoding any addresses - maybe I find out that it will be necessary at some point. But so far it looks fine:

23:08:43.873 -> 0 MCO:BGN:INIT GW,CP=R-NGA---,FQ=8,REL=255,VER=2.3.2
23:08:44.438 -> 585 GWT:TPC:IP=192.168.1.113
23:08:45.468 -> 1589 MCO:BGN:STP
23:08:45.468 -> 1591 MCO:REG:NOT NEEDED
23:08:45.468 -> 1595 MCO:BGN:INIT OK,TSP=NA
23:08:45.468 -> 1597 GWT:TPC:IP=192.168.1.113
23:08:46.464 -> 2600 GWT:RMQ:CONNECTING...
23:08:46.464 -> 2611 GWT:RMQ:OK
23:08:46.464 -> 2613 GWT:TPS:TOPIC=1wire-out/0/255/0/0/17,MSG SENT
23:08:46.497 -> 2619 GWT:TPS:TOPIC=1wire-out/0/255/3/0/11,MSG SENT
23:08:46.497 -> 2625 GWT:TPS:TOPIC=1wire-out/0/255/3/0/12,MSG SENT
23:08:46.497 -> DBG: loop start
23:08:47.559 -> 0 : 280838211713012D
23:08:47.559 -> 3704 GWT:TPS:TOPIC=1wire-out/0/0/1/0/42,MSG SENT
23:08:47.592 -> 0 : 5A014B467FFF0C1044 : 21.62
23:08:47.626 -> 3753 GWT:TPS:TOPIC=1wire-out/0/0/1/0/0,MSG SENT
23:08:47.692 -> 1 : 28A82B7D17130189
23:08:47.692 -> 3825 GWT:TPS:TOPIC=1wire-out/0/1/1/0/42,MSG SENT
23:08:47.692 -> 1 : 53014B467FFF0C102D : 21.19
23:08:47.758 -> 3876 GWT:TPS:TOPIC=1wire-out/0/1/1/0/0,MSG SENT
23:08:47.824 -> 2 : 28949D2816130138
23:08:47.824 -> 3948 GWT:TPS:TOPIC=1wire-out/0/2/1/0/42,MSG SENT
23:08:47.824 -> 2 : 5F014B467FFF0C1012 : 21.94
23:08:47.858 -> 3999 GWT:TPS:TOPIC=1wire-out/0/2/1/0/0,MSG SENT
23:08:47.924 -> 3 : 282C3C2A16130167
23:08:47.924 -> 4071 GWT:TPS:TOPIC=1wire-out/0/3/1/0/42,MSG SENT
23:08:47.957 -> 3 : 56014B467FFF0C107B : 21.37
23:08:47.990 -> 4122 GWT:TPS:TOPIC=1wire-out/0/3/1/0/0,MSG SENT
23:08:48.057 -> 4 : 28FC801F16130104
23:08:48.057 -> 4194 GWT:TPS:TOPIC=1wire-out/0/4/1/0/42,MSG SENT
23:08:48.057 -> 4 : 5C014B467FFF0C10D7 : 21.75
23:08:48.123 -> 4245 GWT:TPS:TOPIC=1wire-out/0/4/1/0/0,MSG SENT
23:08:48.190 -> 5 : 2832312A161301C3
23:08:48.190 -> 4317 GWT:TPS:TOPIC=1wire-out/0/5/1/0/42,MSG SENT
23:08:48.190 -> 5 : 58014B467FFF0C10C2 : 21.50
23:08:48.223 -> 4368 GWT:TPS:TOPIC=1wire-out/0/5/1/0/0,MSG SENT
23:08:48.322 -> 6 : 28CAD31F16130180
23:08:48.322 -> 4440 GWT:TPS:TOPIC=1wire-out/0/6/1/0/42,MSG SENT
23:08:48.322 -> 6 : 57014B467FFF0C1038 : 21.44
23:08:48.356 -> 4489 GWT:TPS:TOPIC=1wire-out/0/6/1/0/0,MSG SENT
23:08:48.422 -> 7 : 28FFE4493118014F
23:08:48.422 -> 4560 GWT:TPS:TOPIC=1wire-out/0/7/1/0/42,MSG SENT
23:08:48.422 -> 7 : 58014B467FFF0C10C2 : 21.50
23:08:48.488 -> 4612 GWT:TPS:TOPIC=1wire-out/0/7/1/0/0,MSG SENT
23:08:48.555 -> 8 : 28FF345E311801AF
23:08:48.555 -> 4683 GWT:TPS:TOPIC=1wire-out/0/8/1/0/42,MSG SENT
23:08:48.555 -> 8 : 5B014B467FFF0C1007 : 21.69
23:08:48.621 -> 4734 GWT:TPS:TOPIC=1wire-out/0/8/1/0/0,MSG SENT
23:08:48.687 -> 9 : 28FF094131180165
23:08:48.687 -> 4806 GWT:TPS:TOPIC=1wire-out/0/9/1/0/42,MSG SENT
23:08:48.687 -> 9 : 55014B467FFF0C10BE : 21.31
23:08:48.721 -> 4855 GWT:TPS:TOPIC=1wire-out/0/9/1/0/0,MSG SENT
23:08:48.787 -> 10 : 28FFE513311802A3
23:08:48.787 -> 4927 GWT:TPS:TOPIC=1wire-out/0/10/1/0/42,MSG SENT
23:08:48.820 -> 10 : 51014B467FFF0C10AB : 21.06
23:08:48.853 -> 4980 GWT:TPS:TOPIC=1wire-out/0/10/1/0/0,MSG SENT
23:08:48.920 -> 11 : 28FF2B1F31180231
23:08:48.920 -> 5052 GWT:TPS:TOPIC=1wire-out/0/11/1/0/42,MSG SENT
23:08:48.920 -> 11 : 56014B467FFF0C107B : 21.37
23:08:48.986 -> 5103 GWT:TPS:TOPIC=1wire-out/0/11/1/0/0,MSG SENT
23:08:48.986 -> DBG: loop end

@mfalkvidd I did not see it - thanks for mentioning it.

I think this is what I was looking for - the sketch uses one MyMessage msg(0,V_TEMP); for values from all DS18B20 with such code construction

  // Read temperatures and send them to controller 
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {
      ...
      // Send in the new temperature
      send(msg.setSensor(i).set(temperature,1));
      ...
  }

I thought I will need to set up MyMessage msg(0,V_TEMP) x number_of_sensors which would be terrible.

I guess if I extend the code with MyMessage msg(0,V_ID) to send also the 1wire address it will be what I am looking for.

Thanks!

Hello

I build mqtt mysensors gateway with DS2482-100 to handle many (currently 15 DS18B20) 1wire sensors.

My idea was that the gateway will dynamically start to report each attached 1wire sensors 1wire address and value automatically without necessity to change the sketch before attaching new sensor. But from what I see I need to set MyMessage(uint8_t childSensorId, uint8_t variableType); first.

Is there some best practice pattern how to do it?

Thanks

Tomas

So I ordered Arduino Uno for programming my Pro Minis. And going to experiment with 2xAA or 3xAA setup without step up booster (they are whining anyway so I will be happy if I get rid of it :)

Thank everyone for help!

@skywatch said in 💬 Battery Powered Sensors:

I think you will find that all the 'good stuff' from the low power library is included in mysensors sleep function anyway.

So when I use sleep() mysensors library overloads the generic arduino sleep?

I suggest using minicore (it is easy to install and all works from within the arduino IDE you are used to) and set internal oscillator and disable BoD. You will need a programmer (a few dollars) or you can use another arduino as programmer. but that is more time consuming to set up and easier to mess up as well!

I look at the git repo and I more confused now. I thought it is some kind of bootloader/firmware I flash. What is Arduino core? I never heard that term.

Good that you got rid of the booster!

I wonder why the booster is recommended here https://www.mysensors.org/build/battery ? Or did I misinterpreted?

@tssk said in 💬 Battery Powered Sensors:

I removed the step up booster connected + directly to VCC but the node stopped working - only the arduino onboard led is constantly on.

The problem was that the batteries I used were not completely fresh. I googled that Arduino pro mini need at least 2.7V to operate. Using fresh batteries the node is working. And it shows 6.0mA in sleep and 25.4mA when transmitting.

So using the stepup booster adds 6.5mA in sleep and 65mA when transmitting to consumption?

I also found LowPower library (https://github.com/rocketscream/Low-Power) but it seems to interfere with mysensors library (https://github.com/rocketscream/Low-Power/issues/80). Any experience?

I removed the step up booster connected + directly to VCC but the node stopped working - only the arduino onboard led is constantly on.

I also tried to measure the step up booster alone and it is showing 0.05 at 20mA on multimeter settings.

I am now really confused and I am not sure what to conclude from that...

I hope I am measuring it correctly.

It shows 12.5 when in sleep and up to 90 when transmitting/measuring.

Any one can interpret that for me please? :)

@TheoL I see so you measure every tim e but send only sometimes. Nice idea thanks.

@skywatch

• This is room sensor and I would like to react to changes in temperature and airquality - I was thinking that I could prolong the interval up to 12min. What do you think is optimal measurements rate for room thermostat?

• Is it possible / necessary to put the radio module to sleep? How to do that?

• So far I did not mess with the Arduino bootloader but I would like to :) Any link that I could read about it? And specifically about the minicore you mention?

• I do not understand what you mean by the pull-up resistors?

• I have my node in the middle of the room around 20-24C that sould not be the problem. Actually it is it main purpose to provide data for optimal room temperature.

• I included step up boosted based on recommendation on the https://www.mysensors.org/build/battery page. I thought it should use the batteries most efficiently. I think I could go with 3 AA batteries. Will I need to regulate the voltage or can I power the radio and bme modules directly?

@mfalkvidd

• I did not know that I need to turn BME off ů how to do that?

• Only thing I found is that Arduino has deepSleep() - but I am not sure if I can use it.

• I am using the default Bw125Cr45Sf128 but thinking about testing Bw125Cr48Sf4096 to achieve greater range.

• Booster is the whining one - https://www.laskarduino.cz/step-up-boost-menic-s-me2108-33v-480ma/

• Is there a way I can measure power draw with multimeter?

// Enable debug prints
//#define MY_DEBUG

// Enable passive mode
#define MY_PASSIVE_NODE

// Passive mode requires static node ID
#define MY_NODE_ID 100

// Enable and select radio type attached
//#define MY_RADIO_RF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
#define MY_RADIO_RFM95

//#define MY_DEBUG_VERBOSE_RFM95
#define MY_RFM95_FREQUENCY (RFM95_868MHZ)
//#define MY_RFM95_MODEM_CONFIGRUATION RFM95_BW31_25CR48SF512
#define MY_RFM95_CS_PIN 8
#define MY_RFM95_IRQ_PIN 2

#include <MySensors.h>
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include "Adafruit_BME680.h"

#define BME_SCK 13
#define BME_MISO 12
#define BME_MOSI 11
#define BME_CS 10

//#define SEALEVELPRESSURE_HPA (1013.25)

// Initialize general message
MyMessage msgTemp( 1, V_TEMP );
MyMessage msgHumi( 2, V_HUM );
MyMessage msgAirq( 3, V_LEVEL );

//Adafruit_BME680 bme; // I2C
Adafruit_BME680 bme(BME_CS); // hardware SPI
//Adafruit_BME680 bme(BME_CS, BME_MOSI, BME_MISO,  BME_SCK);

void setup()
{
  analogReference(INTERNAL);

  if (!bme.begin()) {
    Serial.println( "ERR: BME680 not found" );
    while (1);
  }
  // Set up oversampling and filter initialization
  bme.setTemperatureOversampling(BME680_OS_8X);
  //bme.setPressureOversampling(BME680_OS_4X);
  bme.setHumidityOversampling(BME680_OS_2X);
  bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
  bme.setGasHeater(320, 150); // 320*C for 150 ms

  delay(2000);
  
}

void presentation()
{
	// Send the sketch version information to the gateway and controller
	sendSketchInfo("Room sensor", "4.0");

	// Register all sensors to gw (they will be created as child devices)
  wait(100);
	present( 1, S_TEMP );
  wait(100);
  present( 2, S_HUM );
  wait(100);
  present( 3, S_AIR_QUALITY );

}

void loop()
{

  int batt = analogRead( A3 );
  // 1M, 470K divider across battery and using internal ADC ref of 1.1V
  // Sense point is bypassed with 0.1 uF cap to reduce noise at that point
  // ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
  // 3.44/1023 = Volts per bit = 0.003363075
  int battP = batt / 10;
  #ifdef MY_DEBUG
      float battV  = batt * 0.003363075;
      Serial.print( "Battery Voltage: " );
      Serial.print( battV );
      Serial.println(" V");
      Serial.print( "Battery percent: " );
      Serial.print( battP );
      Serial.println(" %");
  #endif
  wait(100);
  sendBatteryLevel( battP );
  

  if (! bme.performReading()) {
    Serial.println( "ERR: BME680 reading failed" );
    return;
  }
  
  float temp = bme.temperature;
  #ifdef MY_DEBUG
    Serial.print( "DBG: Temperature = " );
    Serial.print( temp );
    Serial.println( " C" );
  #endif
  wait(100);
  send(msgTemp.set( temp, 2 ));
  
  /*
  float pres = bme.pressure/100.00;
  #ifdef MY_DEBUG
    Serial.print( "DBG: Pressure = " );
    Serial.print( pres );
    Serial.println( " hPa" );
  #endif
  wait(100);
  send(msgPres.set(pres,2));
  */
  
  float humi = bme.humidity;
  #ifdef MY_DEBUG
    Serial.print( "DBG: Humidity = " );
    Serial.print( humi );
    Serial.println( " %" );
  #endif
  wait(100);
  send(msgHumi.set( humi, 2 ));
  
  /*
  float alti = bme.readAltitude(SEALEVELPRESSURE_HPA);
  #ifdef MY_DEBUG
    Serial.print( "DBG: Approx. Altitude = " );
    Serial.print( alti );
    Serial.println( " m" );
  #endif
  wait(100);
  send(msgPosi.set(alti,2));
  */

  float airq = bme.gas_resistance / 1000.0;
  #ifdef MY_DEBUG
    Serial.print("DBG: Gas Resistance = ");
    Serial.print( gas );
    Serial.println(" KOhms");
  #endif
  wait(100);
  send(msgAirq.set( airq, 2 ));
  
  
  sleep(10000);
	//sleep(180000);
}

Hello

I would like to ask for help with passive battery powered node I created with following components:

• Arduino pro mini 8MHz - voltage regulator and power LED removed
• SX1276 based 868MHz LoRa radio
• BME680 sensor
• DC-DC 3.3V step-up booster

I created a battery measuring circuit according to scheme on this page ( https://www.mysensors.org/build/battery ).

The problem is the two fresh new AA batteries lasted less than 14 days and stopped when the circuit measured 36%.

2x1.5V AA Aerocell following start and end values:

09.02.2021 16:45 102% (start) : 1.610V and 1.610V
22.02.2021 04:15 36% (end) : 1.001V and -0.150V

The node code is sleeping for 6 minutes between each sensing and sending data.

sleep(180000);

14 days seems very short to me. Is that normal? Is there something I can to make it last longer?

Thanks

@mfalkvidd Thanks.

@mfalkvidd You are right :) I did not know that.

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.
LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.

https://www.arduino.cc/en/pmwiki.php?n=Main/ArduinoBoardProMini

Should I remove the LED to save power? Or it is marginal?

So I used hot glue and it is better. Now I can hear the squeal only when I put my ear directly to the PCB. Thanks for the tips.

@TheoL I have no idea how to measure that.

I noticed that when the radio is transmitting the LED on the Arduino Pro Mini (not the power one) starts blinking very tiny. I still plan to remove the power LED and voltage regulator from the Arduino.

@zboblamont It is not electrical noise but audio noise I can hear. Sorry if I use improper terms.