Incorrect wiring of CrowPi2 7-segment display

In trying to figure out why the segment example doesn't work right, I found that the CrowPi2's 7-segment display is improperly wired. I wrote a segment test that cycles through all the segments of the display and found that the decimal point bit for the first digit is wired to the decimal point indicator of the second digit of the display. The colon of the display is wired to the second digit's decimal point bit. The colon should be wired as a 3rd digit and the 3rd and 4th digit displays should appear in the I2S positions for digits 4 and 5 in order for the Adafruit driver to work.

This is why we need schematics, to confirm whether this is a design bug or a short on the circuit board connecting the wrong things. Based on my experience wiring 7-segment displays since the 80s, I'd say this is a design bug and the display is connected incorrectly to the chip. But I'd really like to see a schematic to confirm this.

Test code:


  • @SpareSimian Hello there! I'm sorry that CrowPi2 is not an open-source project, so I can't provide you with a complete schematic.

    This is the wiring diagram of the 7-segment display module, I hope it can help you.

    Best regards,


  • Thanks! That suggests that the display module (YY2841_AS-33) is defective. It might be a solder splash, though. I'll have to think about what shorts might result in the error I'm seeing. I think I'm missing something important, as I don't see how the colon is supposed to work given the number of pins on the display module. I'm trying to locate a data sheet for the module to see if I can understand that.

  • Aha. It's the module that's wired in a very unintuitive way. It's the Type 2 shown here. So there's no bug in the board.

    I think the version of the Adafruit driver I'm using assumes the type 3 module. (I'm trying to get all the hardware working with the new 64-bit OS and new drivers, so it's been an adventure hunting down the needed code and building new demo scripts.)

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