MLX90640 has stopped responding over I2C

Sensors Distance
1

I have the 55° MLX90640 Qwiic board ([SEN-14844), and after working a for a few days it decided to stop responding over I2C. I confirmed the host wasn’t the problem by trying a different bus on the same controller (Raspberry PI 4B) and with a different controller (BeagleBone Green), and by confirming that a different peripheral (in this case a GridEye Qwiic board) still worked as expected. These connections were all done using both of the Qwiic connectors, and the test was done using i2cdetect to see if the device responded on 0x33.

I also tested the sensor board with a Bus Pirate, using the breakout holes on the bottom of the board. The Bus Pirate’s I2C device detection macro reported that there was either a short or that there were no pull-ups (changing the pull-up settings on the Bus Pirate did not make the sensor). Searching the forums here there were references to SDA and/or SCL getting shorted to ground (posts [219954 and [203899), and checking with a multimeter on this board that does seem to be the case (about 10Ω between either SCL or SDA and ground). A moderator reply on post #219954 seems to suggest that desoldering the sensor myself and resoldering it with a slight gap between the sensor and the board could correct the issue, but I’ve only been using this sensor for about a week and this seems like a known issue with the board.](MLX90640 SDA+GND shorted upon delivery - SparkFun Electronics Forum)](Problem with MLX90640 - SparkFun Electronics Forum)](SparkFun IR Array Breakout - 55 Degree FOV, MLX90640 (Qwiic) - SEN-14844 - SparkFun Electronics)

2

Desoldering/resoldering with a gap will probably resolve the issue but if you’d like to replace the board and you purchased it directly from the SparkFun website, fill in the [form on this page with your order number and a link to this forum post and I can get you a replacement. :-)](Return Policy - SparkFun Electronics)

3

I experienced the same issue (SDA stuck to GND) after some tests. Unfortunately, living in Europe, I purchased the module through a European distributor (Elektor). Moreover, this is a replacement device. The previous one failed similarly almost immediately :frowning:

I confirm that carefully lifting the sensor over the PCB solved the issue. If it can help someone: I avoided using an air gun soldering iron, I adjusted the temperature of the soldering iron to 410°C and used pliers to pull gently the sensor while shunting as much as possible the heating of the sensor.