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tca9539: TCA9539 I2C To GPIO Not Working Properly

Part Number: TCA9539
Other Parts Discussed in Thread: TCA9535

Hello all,

Greetings

We are developing our customize board using TCA9535 I2C to GPIO Extender.Which is interface with Rasperry Pi 3 through I2c interface also we are connecting one LED as a output (GPIO number P07) on GPIO Extender IC.
when we run continous led blinking program that time led blink proper some times(approximate 5-6 hours) then after GPIO do not get the proper data during this time we are checking SCK and SDA input line of GPIO Extender IC and we are getting proper clock and data.
Moreover, below i attached schematic:

Issue: after GPIO do not get the proper data during this time we are checking SCK and SDA input line of GPIO Extender IC and we are getting proper clock and data.

Please kindly share your valuable input

  • Hey Hardik,

    Just to clarify, are you saying that after a certain amount of time the GPIO does not get proper data:
    1) You cannot write to the registers?
    2) The registers written to are incorrect. (ex. register 0x06 should be FF but is instead 00)
    3) You are receiving a NACK when you try to read/write?

    I2C address from your schematic looks like it needs to be 0x74h. I assume this is the same address you are trying to write to.If my understanding is correct in the schematic, you are sending 1110 1000 to write and 1110 1001 to read. If so, the write and read commands look correct.

    Can you post a scope shot of when you write and read and when this error occurs?

    Thanks,
    -Bobby