Just a heads up: IRQ Pin on Joywing and TFT featherwing SD slot gotcha

Hi guys,

Just thought I’d mention that if you try to use the TFT Featherwing and the Adafruit Seesaw Joywing together, you will run into a conflict with the IRQ Pin. This is due, in my understanding, to the SD Card slot on the Featherwing takes priority over the Joywing’s IRQ.

From what I understand:

  1. The TFT Featherwing also uses the IRQ pin as a SD Card Interrupt Pin and uses that to read/write to the SD Card.
  2. The Joywing uses the IRQ pin as an interrupt to tell the base board (ESP in my case) that there’s activity and it should get the bitmask back from the Seesaw controller

You can use just the joystick without any drama, but if you try to use the buttons, you will get no response. So what I have done is ordered a third party SPI compatible display, and going to wire it up manually (ie. not using the Featherwing itself).

You can view my original github complaint/bug report here at this link. Ladyada was originally not helpful, but I eventually got her to look into this properly and she confirmed that it was working on hers. I later traced it to the SD Card slot IRQ pin.

If any of the Core Electronics team want to put a note on their listing (after checking my statements are correct, of course) on either the Joywing or TFT Featherwing then please feel free to. I’m merely leaving this here as a point of reference for anyone else who runs into trouble.

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Thanks for the info Matthew!

Did you get everything working on your project?


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Yup, got it all sorted. Once I switched to another TFT shield (not Adafruit Featherwing branded) the joystick and buttons started working fine.


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