BQ25713: I2C - debug lack of answer? Part Number: BQ25713 Hi, Any ideas whats going wrong here trying to get I2C communication working with the charger IC? suggestions? Using the EVM board, but not the usb-i2c connector or your software (do not have them). so our microcontroller and our code. the trace is taken at the EVM jumper for SDA and SCL. EVM has power. On the right of the below trace i expect manuf ID 0x40, not 0xFF (its reading 2 bytes for no good reason). Same result for ChargeOption0 To go through the test from left to right The board address is 6B ->D6,D7. register 0x14 does not exist to test for NACK . register 0x2E should return manufacture id 0x40. register 0x00 ChargeOption0 should default to 0xE60E. thanks in advance Hi, Brad, Could you capture another waveform usingcompany connector andcompany software? so we can compare both waveforms and find the differences. As written in the original post I do not have them (i.e. no EV2400). By the time I realised the EVM had been ordered without it, we didnt want to wait for Covid time frame ordering so wrote the I2C code (TI could replicate reasonably easily with the 2 registers shown in the main post) Hi, Brad, I am not a digital engineer. I checked the pulse train when reading 0x2E, it returns 0x40 correctly. I can see there is another Start signal in the second byte. The pulses are "S 1101 0110 A 0010 1110 A S 1101 0111 A 0100 0000 1 P" Tiger Zhou I am not a digital engineer me neither :) thankyou for picking that up. The missing start signal was required from master. now seeing the expected manufacturer id 0x40 and device 0x88