BH1745 communication not working

Other Hardware Sensors
1

My friend and I are trying to write a library for the Pimoroni BH1745 color sensor breakout, as the existing libraries do not completely support all features. However, Wire.available() always returns 0 when reading registers, even though we have confirmed the sensor working using the official example and a Raspberry Pi Pico. For testing, I also tried the exact I2C code from another library, also confirmed working, but it didn't help. Our code is available on Codeberg:
void_panic/arduino-bh1745: Arduino bindings for the BH1745 RGB color sensor - Codeberg.org

2

That is telling me there is no data available. Without an annotated schematic showing exactly how this was wired and the code all I can do is make guesses which is a waist of time for both of us.

3

Can you implement this very simple code to check if it works? pay attention to the wire part inside the class:

BH1745.h

/**
    *******************************************************************************************

  * @file           : BH1745.h
  * @brief          : BH1745 Library
    *******************************************************************************************
  * The BH1745 is a digital color sensor IC with I2C bus interface...
  *   
  * @details
  * 
  *
  *******************************************************************************************
  */

#include <Arduino.h>
#include <Math.h>
#include <Wire.h>

#ifndef INC_BH1745_H_
#define INC_BH1745_H_

#define BH1745_ADDRESS_1                  0x38 // If ADDR Pin = '0'
#define BH1745_ADDRESS_2                  0x39 // If ADDR Pin = '1'
#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))

// Registers
#define BH1745_SYSTEM_CONTROL            0x40  
#define BH1745_MODE_CONTROL1             0x41  
#define BH1745_MODE_CONTROL2             0x42
#define BH1745_MODE_CONTROL3             0x44
#define BH1745_RED_DATA_LSB              0x50
#define BH1745_RED_DATA_MSB              0x51
#define BH1745_GREEN_DATA_LSB            0x52
#define BH1745_GREEN_DATA_MSB            0x53
#define BH1745_BLUE_DATA_LSB             0x54
#define BH1745_BLUE_DATA_MSB             0x55
#define BH1745_CLEAR_DATA_LSB            0x56
#define BH1745_CLEAR_DATA_MSB            0x57
#define BH1745_DINT_DATA_LSB             0x58
#define BH1745_DINT_DATA_MSB             0x59
#define BH1745_INTERRUPT                 0x60
#define BH1745_PERSISTENCE               0x61
#define BH1745_TH_LSB                    0x62
#define BH1745_TH_MSB                    0x63
#define BH1745_TL_LSB                    0x64
#define BH1745_TL_MSB                    0x65
#define BH1745_MANUFACTURER_ID           0x92

class BH1745{
  public:
    BH1745(); // Constructor. It must be defined with the same name as the class

    void     init(uint8_t devAddress, TwoWire *wire = &Wire);
    
    void     writeRegister(uint8_t registerAddress, uint8_t value);
    uint8_t  readRegister(uint8_t registerAddress);

    uint8_t  getManufacturerId();

  private:
    uint8_t _deviceAddress;
    TwoWire * _wire; //The generic connection to user's chosen I2C hardware
};

#endif

BH1745.cpp

#include <BH1745.h>
#include <Wire.h>
#include "math.h"

// Constructor
BH1745::BH1745()
{

}

void BH1745::writeRegister(uint8_t registerAddress, uint8_t value)
{
    _wire->beginTransmission(_deviceAddress);
    _wire->write(registerAddress);
    _wire->write(value);
    return _wire->endTransmission();
}

uint8_t BH1745::readRegister(uint8_t registerAddress)
{
    _wire->beginTransmission(_deviceAddress);
    _wire->write(registerAddress);
    _wire->endTransmission();
    _wire->requestFrom(_deviceAddress, (uint8_t)1);
    uint8_t value = _wire->read();
    return value;
}

void BH1745::init(uint8_t devAddress, TwoWire *wire)
{
    _deviceAddress = devAddress;
    _wire          = wire;

    //Your code here. Yo can initialize your MODE_CONTROL registers for example 
}

uint8_t BH1745::getManufacturerId()
{
  uint8_t value = readRegister(BH1745_MANUFACTURER_ID);
  return value;
}

BH1745_Example.ino

#include <BH1745.h>

BH1745 bh1745;

char s1[10];
uint8_t registerValue;

void setup() {
  // put your setup code here, to run once:
  Wire.begin();
  Wire.setClock(400000);
  Serial.begin(115200);    // Start serial communication at 115200 baud
  while (!Serial) {
    // will pause Zero, Leonardo, etc until serial console opens
    delay(1);
  }

  bh1745.init(BH1745_ADDRESS_1);
}

void loop() {
  // put your main code here, to run repeatedly:
  registerValue = bh1745.getManufacturerId();

  sprintf(s1, "%02X", registerValue);

  Serial.print("MANUFACTURER ID Register: 0x"); Serial.println(s1);
  delay(1000);
}