We're happy to report that the PCA9634 IC that controls the columns of our LED display is now working as expected. This was a tricky case to solve so let us share the journey of finding the solution.
When starting to debug the problem it was rather strange that the Bus Pirate almost exclusively showed START and STOP bits but almost no actual payload. This shouldn't have happened because the I2C bus was clocked at 400kHz and the Bus Pirate should be able to decode 400kHz I2C communication because this very frequency can be selected from its menu. I still don't know what's wrong with my Bus Pirate but I ordered a new, more modern one which is on its way. Looking for alternative ways to track down the issue I broken out SDA and SCL, added a status LED to the board and reached for my Open Bench Logic Sniffer.
LED Strip PCB,LED TV PCB Board,backlight pcb
Metal CorePCB Manufacturer
UL approved and RoHS compliant
Good quality and reasonable price
Material: Bergquist MP-06503,HR T30.20
Surface Finish: Lead free HASL,ENIG,OSP,etc
Solder Mask Color: White, black,etc
Aluminum PCB Application: LED Lighting, LED TV,Automotive Electronics,Electric Vehicle,Power Conversion,Motor Drivers,Concentrator Photovoltaic, Audio, Aviation and Military Industry