Troubleshooting • Re: raspPi 4B i2c cannot detect address

Hello neigl,

it is not good that cannot upload a image to show the waveform of SDA.1 and SCL.1.
I want to say that 1month ago, I used this rasp Pi device to control outside board to do DC-motor running with I2C port, it worked
but now, when I run the program again, I cannot get the outside board's address.

I checked the waveform that SDA.1 cannot reach low level. just like below
sda.1 --- | |---| |-------| |---------
|__| |__| |___|


0V here ---------------------------------------------

what is the problew?

even though, i checked the rasp Pi SDA.1 and SCL.1 without connecting anything, directly to ocilloscope. the waveform is the same as above.
SDA.1 cannot reach to low level. SCL.1 is normal working.

Please someone help me.

Thanks.

Statistics: Posted by dqsh06 — Thu Mar 27, 2025 9:14 am

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