***Solved*** AB02S I2C1 Intermittent. Please Help

[ibrahimenrique]

Hello People, I need some help and ideas here.

I am testing the AB02S second I2C bus (I2C1). I am using the Examples/Basics/I2C/i2c_scan file. It is woring ok (for newbies, to use the second I2C bus, wire1 must be used instead of wire in the file body).

I tested a sensor SHT30A, it has pull up 2.2 Kohm resistors incorporated. It worked just fine, it always recognized the sensor (https://www.adafruit.com/product/4099).

I included in the bus a MAX10102 (with no resistors) and worked just fine…

Then I tested a sensor ADXL345 alone (it has 4.7Kohm pull up resistors), it was identified some times and other times it was not. I removed the resistors on this one and add it to the bus with the others 2 and worked just fine… So maybe there could be some issued with the resistors…

Then I tested a MLX90614 and it was never recognized with or without the resistences (the sensor works just fine in an Arduino and in another ESP32 board).

The MLX90614 comes in a board LW-691, I removed the pull up to add it to the bus, it is not communicating… Alone in the bus with its 4.7 pull up, do not communciates neighet. I used 1K resistors and nothing…

GY-906 MLX90614 Non-Contact Precision Thermometer Module - ProtoSupplies

The sensor is good, and it communciates with the Arduino One… What could be the problem? I am using the same buss speed in the arduino and in the AB02S

Thank you all!

[UniquePete]

I had a problem with an I²C EEPROM that turned out to be the I²C bus speed. In that case, the datasheet explicitly states that when running on 3.3V the bus clocking should not exceed 100kHz, which is what will be used if you don’t specify a higher clocking rate. If you are already using the default bus speed, you could try inserting a small delay between your sensor access commands.

I still have one I²C sensor, a VEML6075, that doesn’t want to play ball with a CubeCell—it works just fine with ESP-12 & ESP32 processors.

[ibrahimenrique]

I set the clock in the wire.h file from 100k to 50k and nothing…

[ibrahimenrique]

I made it work. In fact it seems to be a problem with the cubecell wire library.
I used the wire library in this post

Doesn't work MLX90614 by SubeCell Board

Hello there, I made it work. the I2C scan recognize the MLX90614, it is commnicating in a bus with other 3 sensors!. But now the sparkfun library is not retrieving the temp. value.Did you make any adjustment in the SparkFun library? (apart of wire1) [image]

and it worked… just be sure that you remove all teh other wire refrences from the library directory, otherwise will not work.
The MLX90614 is in the second I2C bus with other 3 sensors… all address can be retrieved. MLX90614 address is 0x5A