BH1750 Lux Sensor Problems

[Toine33]

Hey Guys,

I am trying for an while now but i cant make it work.
The problem is that when i use this sketch i cant get usable data out of the BH1750

#define MY_DEBUG
#define MY_RS485
#define MY_RS485_DE_PIN 2
#define MY_RS485_BAUD_RATE 19200
#define MY_RS485_HWSERIAL Serial
#define MY_NODE_ID 5


#include <SPI.h>
#include <MySensors.h>
#include <BH1750.h>
#include <Wire.h>

#define CHILD_ID_LIGHT 25
unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)

BH1750 lightSensor;

// V_LIGHT_LEVEL should only be used for uncalibrated light level 0-100%.
// If your controller supports the new V_LEVEL variable, use this instead for
// transmitting LUX light level.
MyMessage msg(CHILD_ID_LIGHT, V_LIGHT_LEVEL);
// MyMessage msg(CHILD_ID_LIGHT, V_LEVEL);  
uint16_t lastlux;

void setup()  
{ 
  lightSensor.begin();
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Node 5", "1.0");

  // Register all sensors to gateway (they will be created as child devices)
  present(CHILD_ID_LIGHT, S_LIGHT_LEVEL);
}

void loop()      
{     
  uint16_t lux = lightSensor.readLightLevel();// Get Lux value
  Serial.println(lux);
  if (lux != lastlux) {
      send(msg.set(lux));
      lastlux = lux;
  }

  wait(SLEEP_TIME);
}

The output i am receiving is 65534 LUX and it never changes..

The weird part is when i use this sketch without changing wiring i am receiving good changing data like 110 Lux etc etc

#include <Wire.h>
#include <BH1750.h>

BH1750 lichtMeter;

void setup(){
  Serial.begin(9600);
  lichtMeter.begin();
}
 
 
void loop() {
  uint16_t lux = lichtMeter.readLightLevel();
  Serial.print("Licht: ");
  Serial.print(lux);
  Serial.println(" lux");
  delay(500);
}

#include <Wire.h>
#include <BH1750.h>
 
BH1750 lichtMeter;
 
void setup(){
  Serial.begin(9600);
  lichtMeter.begin();
}
 
 
void loop() {
  uint16_t lux = lichtMeter.readLightLevel();
  Serial.print("Licht: ");
  Serial.print(lux);
  Serial.println(" lux");
  delay(500);
}

Hardware:
Arduino nano - Node - RS485

[Nca78]

@toine33 said in BH1750 Lux Sensor Problems:

V_LIGHT_LEVEL

Hello, do you get this with the serial print or in your controler from MySensors ?

Because the light level in Lux should be with a V_LEVEL message and not V_LIGHT_LEVEL which expects a value from 0 to 100%. This could mess with the value reported on the controller side.

[Toine33]

@Nca78

I have tried both and still no luck, the weird part is that it is working without the MySenors part.
When i am adding Mysensors libary it stops working.
The node can present itself succesfull on the gateway and also creates the child ID 25 (LUX Sensor).

[Nca78]

I'm not familiar at all with RS485 but are your sure this is not messing up with the MY_DEBUG and the Serial.println() in the code ?

@toine33 said in BH1750 Lux Sensor Problems:

#define MY_RS485_HWSERIAL Serial

[Toine33]

@nca78

I Realy have no clue at the moment, i have tried almost everything for what i can think of.
Also removed the serial print but still no luck.
For the rest of the node's i never had issues.

I have tried different sensors / Different arduino's but as soon when i am activating the mysensors part it stops responding.

[Toine33]

I guess i found it now,
Looks like that V_LEVEL and V_LIGHT_LEVEL are both not behaving as expected,
I have changed these now to V_TEXT after that the sensors was finaly working within domoticz.

Also i had some cabeling issues, looks like the sensor doesnt like an cable length off 2 meter on 4x 0,44mm2 wire..
Tommorow i am going to place the arduino closer to the weather station and i guess everything would be fine again then !

Here my latest sketch:

#define MY_DEBUG
#define MY_RS485
#define MY_RS485_DE_PIN 2
#define MY_RS485_BAUD_RATE 19200
#define MY_RS485_HWSERIAL Serial
#define MY_NODE_ID 5


#include <MySensors.h>  
#include <BH1750.h>
#include <Wire.h>

#define CHILD_ID_LIGHT 25
unsigned long SLEEP_TIME = 25000; // Sleep time between reads (in milliseconds)

BH1750 lightSensor;

// V_LIGHT_LEVEL should only be used for uncalibrated light level 0-100%.
// If your controller supports the new V_LEVEL variable, use this instead for
// transmitting LUX light level.
// MyMessage msg(CHILD_ID_LIGHT, V_LIGHT_LEVEL);
MyMessage msg(CHILD_ID_LIGHT, V_TEXT);  
uint16_t lastlux;

void setup()  
{ 
  lightSensor.begin();
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Node 5", "1.0");

  // Register all sensors to gateway (they will be created as child devices)
  present(CHILD_ID_LIGHT, S_BINARY);
}

void loop()      
{     
  uint16_t lux = lightSensor.readLightLevel();// Get Lux value
 // Serial.println(lux);
 // if (lux != lastlux) {
      send(msg.set(lux));
     // lastlux = lux;
 // }

  wait(SLEEP_TIME);
}

@Nca78
Thanks for your help !