I found an root cause.

In pin definition was

#define AIQ_SENSOR_ANALOG_PIN 1

but should be

#define AIQ_SENSOR_ANALOG_PIN A1

I do not know why with first definition it worked with nano but did not work with mini.

@rejoe2 said in MQ135 with RS485:

NodeID

Hmm, I tried to define sensor as 30 but still the same result. In log of sensor I can see

114875 !TSM:FPAR:NO REPLY
114877 TSM:FPAR
114895 TSF:MSG:SEND,30-30-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:

I think that it is not a case. As I told everything works with arduino nano.

How I can check if data from sensor are reading?
It seems that code does not continue if sensor is not connected to gateway.

Now I replaced mini pro and used nano instead. Data were send successfully.

Do you have any idea what can be wrong with mini pro?

Hello,

I try to get working my MQ135 on RS485 but I cannot manage to make it working.

I use UNO as Gateway + 2 separate sensors (DHT on UNO and MQ135 on pro mini 5V)
DHT works correctly but MQ135 does not work.

For testing purpose I disconnected DHT.

I wanted to be sure that MQ135 is connected correctly so I uploaded another code and everything works correctly, But with code below I cannot send data to gateway. I used as a source of code following MySensor forum code

Connection

MQ135 - arduino pro mini 5V
Vcc - Vcc 5V
GND - GND
AO - A1

RS485 - arduino pro mini 5V
DI - D9
R0 - D8
DE/RE - D2
GND - GND
Vcc - Vcc 5V
A - A(gateway RS485)
A - A(gateway RS485)

CODE

/*
  Arduino MQ135
  connect the sensor as follows :
  A H A   >>> 5V
  B       >>> A0
  H       >>> GND
  B       >>> 10K ohm >>> GND
 
  Contribution: epierre
  Based on David Gironi http://davidegironi.blogspot.fr/2014/01/cheap-co2-meter-using-mq135-sensor-with.html
  http://skylink.dl.sourceforge.net/project/davidegironi/avr-lib/avr_lib_mq135_01.zip
 
*/

// Enable debug prints
#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 this if RS485 is connected to a hardware serial port
//#define MY_RS485_HWSERIAL Serial1

// #include <SPI.h>    
//#include <MySensor.h>
#include <MySensors.h>
#include <Wire.h> 

#define CHILD_ID_AIQ 0
#define AIQ_SENSOR_ANALOG_PIN 1

#define MQ135_DEFAULTPPM 399 //default ppm of CO2 for calibration
#define MQ135_DEFAULTRO 68550 //default Ro for MQ135_DEFAULTPPM ppm of CO2
#define MQ135_SCALINGFACTOR 116.6020682 //CO2 gas value
#define MQ135_EXPONENT -2.769034857 //CO2 gas value
#define MQ135_MAXRSRO 2.428 //for CO2
#define MQ135_MINRSRO 0.358 //for CO2

unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in seconds)
//VARIABLES
float mq135_ro = 10000.0;    // this has to be tuned 10K Ohm
int val = 0;                 // variable to store the value coming from the sensor
float valAIQ =0.0;
float lastAIQ =0.0;

// MySensor gw;
MyMessage msg(CHILD_ID_AIQ, V_LEVEL);

void setup()  
{
//  gw.begin();

  // Send the sketch version information to the gateway and Controller
 // gw.sendSketchInfo("AIQ Sensor MQ135", "1.0");

  // Register all sensors to gateway (they will be created as child devices)
//  gw.present(CHILD_ID_AIQ, S_AIR_QUALITY);  
   
}

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("AIQ Sensor MQ135", "1.0");
 
  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID_AIQ, S_AIR_QUALITY);  
}

/*
 * get the calibrated ro based upon read resistance, and a know ppm
 */
long mq135_getro(long resvalue, double ppm) {
return (long)(resvalue * exp( log(MQ135_SCALINGFACTOR/ppm) / MQ135_EXPONENT ));
}

/*
 * get the ppm concentration
 */
double mq135_getppm(long resvalue, long ro) {
double ret = 0;
double validinterval = 0;
validinterval = resvalue/(double)ro;
if(validinterval<MQ135_MAXRSRO && validinterval>MQ135_MINRSRO) {
ret = (double)MQ135_SCALINGFACTOR * pow( ((double)resvalue/ro), MQ135_EXPONENT);
}
return ret;
}

void loop()      
{    
  uint16_t valr = analogRead(AIQ_SENSOR_ANALOG_PIN);// Get AIQ value
  Serial.println(val);
  uint16_t val =  ((float)22000*(1023-valr)/valr); 
  //during clean air calibration, read the Ro value and replace MQ135_DEFAULTRO value with it, you can even deactivate following function call.
  mq135_ro = mq135_getro(val, MQ135_DEFAULTPPM);
  //convert to ppm (using default ro)
  valAIQ = mq135_getppm(val, MQ135_DEFAULTRO);

  Serial.print ( "Val / Ro / value:");
  Serial.print ( val);
  Serial.print ( " / ");
  Serial.print ( mq135_ro);
  Serial.print ( " / ");
  Serial.print ( valAIQ);

 
  if (valAIQ != lastAIQ) {
    //  gw.send(msg.set(MQ135_DEFAULTPPM+(int)ceil(valAIQ)));
       send(msg.set(MQ135_DEFAULTPPM+(int)ceil(valAIQ)));
      lastAIQ = ceil(valAIQ);
  }
 
  // Power down the radio.  Note that the radio will get powered back up
  // on the next write() call.
  //gw.sleep(SLEEP_TIME); //sleep for: sleepTime
  sleep(SLEEP_TIME); //sleep for: sleepTime
}

 
/*****************************  MQGetPercentage **********************************
Input:   rs_ro_ratio - Rs divided by Ro
         pcurve      - pointer to the curve of the target gas
Output:  ppm of the target gas
Remarks: By using the slope and a point of the line. The x(logarithmic value of ppm) 
         of the line could be derived if y(rs_ro_ratio) is provided. As it is a 
         logarithmic coordinate, power of 10 is used to convert the result to non-logarithmic 
         value.
************************************************************************************/ 
int  MQGetPercentage(float rs_ro_ratio, float ro, float *pcurve)
{
  return (double)(pcurve[0] * pow(((double)rs_ro_ratio/ro), pcurve[1]));
}

SENSOR LOG

16 MCO:BGN:INIT NODE,CP=RSNNA---,REL=255,VER=2.3.1
26 TSM:INIT
27 TSF:WUR:MS=0
28 TSM:INIT:TSP OK
30 TSM:FPAR
49 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
2056 !TSM:FPAR:NO REPLY
2058 TSM:FPAR
2075 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
4083 !TSM:FPAR:NO REPLY
4085 TSM:FPAR
4103 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
6111 !TSM:FPAR:NO REPLY
6113 TSM:FPAR
6130 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
8138 !TSM:FPAR:FAIL
8139 TSM:FAIL:CNT=1
8141 TSM:FAIL:DIS
8143 TSF:TDI:TSL

GATEWAY LOG

0;255;3;0;9;0 MCO:BGN:INIT GW,CP=RSNGA---,REL=255,VER=2.3.1
0;255;3;0;9;5 TSM:INIT
0;255;3;0;9;7 TSF:WUR:MS=0
0;255;3;0;9;9 TSM:INIT:TSP OK
0;255;3;0;9;12 TSM:INIT:GW MODE
0;255;3;0;9;15 TSM:READY:ID=0,PAR=0,DIS=0
0;255;3;0;9;18 MCO:REG:NOT NEEDED
0;255;3;0;14;Gateway startup complete.
0;255;0;0;18;2.3.1
0;255;3;0;9;23 MCO:BGN:STP
0;255;3;0;9;29 MCO:BGN:INIT OK,TSP=1
0;255;3;0;9;32 TSM:READY:NWD REQ
0;255;3;0;9;52 TSF:MSG:SEND,0-0-255-255,s=255,c=3,t=20,pt=0,l=0,sg=0,ft=0,st=OK:

Thank you very much for any help!!!

Thank you very much for great explanation!!!

But is there a way how to connect ESP8266 to Controller. In MySensors are available just ethernet or serial gateway with NRF. Of course I can connect ESP to NRF and then use serial gateway but then there is no difference if I use ESP or nano.

My idea is that I want to use wireless network for sensors. One of my sensor should be LCD/TFT with touch so I wanted to prevent to use NRF (it occuy SPI)
https://forum.mysensors.org/topic/9276/home-automation-tft-touch-display

Hello,

Maybe I have a stupid question but I did not find proper information on this forum or internet.

Currently I use serial gateway (Uno + NRF24 connected via USB, MyController) for connection of sensors. So sensors are arduinos (uno, mini, ...) with sensor and NRF24.

And now my stupid question. Can I connect WeMos D1 mini directly to my gateway (without NRF24)? Both items works on 2.4GHz.

Thank you for your reply

Hello,

I would like to promote my home automation system and be able to control room settings for each room.

I use MySensors + MyController.

In rooms I measure Temperature, Humidity, AirQuality, and I control air condition, heating and electronic window blind.

I would like to have a TFT touch display in each room with possibility to see all measured values and (on button click or slide) + be able to control temperature (thermostat), open or close window blind.

Additionally i would like to build it small .. not like on mega but on nano. Unfortunatley NRF and TFT use MISO/MOSI so I need to use custom pins for TFT.

Do you know if it is doable and could you recommend solution/concept?

Thank you very much!