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BQ76942: I2C communication

Part Number: BQ76942

Hi Team,

The use environment is the combination of MCU+BQ76942. The I2C of the MCU on the PCB and the I2C of the BQ76942 are connected together by a series of 100R resistors, but the MCU is an empty program and does not communicate with the BQ76942; under this premise, use BQ studio and BQ76942 communication, it is found that BQ studio cannot detect the chip, and the communication is always unsuccessful. But remove the resistance, that is, the MCU on the PCB board and the I2C of the BQ76942 are disconnected, and then go to communicate with the BQ studio, and the communication can be successful. why is this happening? Is it just that the I2C of the MCU and the I2C of the BQ76942 are connected together without communication, will it also affect the communication between the BQ76942 and BQ studio?

Beat Regards,
Tom Liu

  • Hi Tom,

    Most likely the MCU is pulling the SCL / SDA lines low or high preventing successful communication. I do not know the details of your MCU - I would recommend setting these pins to a Hi-Z state.

    Best regards,