MicroPython Forum (Archive)

I am using a pyboard connected to an adafruit Si5351 eval board. I have gnd and 3v3 on the pyboard connected to GND and VIN of the Si5351 board. The I2C interface on the Si5351 board is connected to X9 (clock) and X10 (data) of the pyboard. When I call i2c.scan(), the return is as follows:

[8, 9, 10, 11, ... , 118, 119]

So I get integer values from 8 to 119, which is unexpected.

From the Si5351 datasheet, page 18 at the bottom, I am expecting i2c.scan() to return [96], or 0x60.
https://www.skyworksinc.com/-/media/Sky ... 5351-B.pdf

Can anyone explain this behavior that I am seeing?

Thanks
Andy

Andrew1234 wrote: ↑

Mon Jul 18, 2022 12:33 am

Can anyone explain this behavior that I am seeing?

My first guess would be the usual I2C sort of things like pull-up resistors, but it appears this breakout board has them (on both sides of the level shifter).

Do you have a scope or logic analyser?

Out of curiosity, if you talk to the expected address does it work?

FYI, not sure if you saw this already but I came across
https://www.youtube.com/watch?v=2cb1LLoeT-Y
https://github.com/thaaraak/Tinypico-Radio
which might be useful.

Hi Jimmo
Thanks for your input. I'll try talking to the device at the expected address and see what I get. I do have a scope and can try to analyze the signals as well. Yes, the library you found is the very one that I am trying to use. Unfortunately I didn't find a test script in that repository that I can start from, but I get the basic idea from the youtube video.

Regards
Andy