Spare pins with R4 and DIYables 3.5 TFT touch Displa

Official Hardware UNO Family UNO R4 WiFi
1

I am using the DIYables 3.5 TFT Touch displays with an Arduino UNO R4 WiFi. Everything is working very well, so far.

However, I need also to be able to use two digital pins, one as a digital input, reading a temperature, and one as a digital output, driving a relay.

Are there at least two pins not being used by the display that I can use safely for these purposes?

I’ve searched for an answer with no success.

Thank you, Ralph

2

Can you not just look at the board and see? Becxause I can't, you didn't post a wiring diagram or the code.

3

Because the display is a shield, there is no "wiring diagram” and I’m not sure how my code would help. The library that uses the pins directly is <DIYables_TFT_Touch_Shield.h> and is on GitHub. I am not experienced enough, nor clever enough, to plough through the library source code to work out which pins are not used.

I received a a very helpful reply from DIYables. I thought I would share it for the benefit of others:

"Regarding your question, the shield uses the following pins: D2, D3, D4, D5, D6, D7, D8, D9, A0, A1, A2, A3, A4

It means that you can freely use the following pins for other purposes: DO, D1, D10, D11, D12, D13, A5.
However:

  • if you use the SDcard, you cannot use D10, D11, D12, and D13.
  • if you use Serial, you cannot use D0 and D1.

Please note that pin A5 can be used as digital or analog.”

Thanks,

Ralph

1 Like
4

See how easy it is when all the relevant info is disclosed.

5

Actually, since you're using an Uno R4, you can use Serial and D0 and D1 are still available, as they're (optionally) used for Serial1, not Serial as in the R3.

1 Like
6

Thank you, van_der_decken, that is a very good point! Those two pins are particularly useful as they are not covered by the headers on the display shield and so are more accessible.

Thanks, Ralph

7

Yes, it is correct, As @ralpnc and @van_der_decken said.

For anyone who searching for the awnser in the future and reach this thread, please refer to the below table for pin map:

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image951×658 69.3 KB

You can get more information on the product page of 3.5 inch TFT Touch Shield