Hi, I'm testing the VEML7700 sensor with the ARDUINO DUE board using the I2C interface (SDA0, SCL0). Despite the sensor is seen with i2cScanner at 0X10 (correctly) only ZERO LUX values are received. I tried the ADAFRUIT VEML7700 library, the SPARKFUN VEML7700 library, and the DFROBOT VEML7700 library. I used the examples provided in the library (VEML7700test, example1_getlux, and READVEML7700, respectively). However, if I use ARDUINO UNO (5V) or ESP32 boards (3.3V), readings for VEML7700 are correct for ALL three different libraries. Is there any particular trick to let it work with the ARDUINO DUE BOARD? Thanks
The Arduino Due uses 3.3V logic, like the VEML7700, but its I2C lines have very weak internal pull-ups, which are often not enough. The sensor might be detected at address 0x10, but actual data transfers like lux readings can silently fail if pull-ups are too weak.
Did you try adding external pull-up resistors of around 4.7kΩ to 3.3V to SDA0 and SCL0?
Thank you for the replay. No, not yet tried. But according to DUE schematic there is a 1.5k resistor pull-up tò 3.3v for wire0 (but nothing for wire1). Any other suggestion? Thanks.