I recently purchased several of the DFRobot ledkeypad shields: https://www.dfrobot.com/product-1407.html

I have Arduino Leonardo (which also had some problems in the beginning, being recognized as modems). My OS is Linux Mint, and I'm using the last Arduino IDE.

The library I use is the one recommended on the website of the vendor, LedKeypad.h, and works fine with the other shields of the same model from the same batch.

Some shields worked fine but I am now having trouble with one of them, which seems unresponsive. I can load for instance the blink program in the arduino, and it works, but the shield does not work. When it is plugged in, the fours dots are slightly red, and I cannot turn them off.

I tried displaying something on the serial monitor when the buttons are pushed, and only one of the 5 buttons works (the KEY_DOWN one).

Is there anything I can attempt to fix the problem ? Or should I just give up on this shield ?

  • 1
    the information that you have posted is incomplete. ... there is no mention of software ... please include all info in the question ... do not use comments to add info
    – jsotola
    Dec 25, 2017 at 19:41
  • @jsotola added software info, is all the relevant information there ?
    – Denis
    Dec 25, 2017 at 21:54
  • what i am talking about is that you made no mention of any libraries for the arduino. there is no way to tell if you downloaded the correct libraries.
    – jsotola
    Dec 26, 2017 at 2:08
  • @jsotola oh sorry I added info about the library
    – Denis
    Dec 26, 2017 at 12:29

1 Answer 1


... and works fine with the other shields of the same model from the same batch.

So had you considered that the shield might be faulty? Have you contacted the manufacturer or vendor for support?

  • The schematic seems to show that it uses the actual SDA/SCL pins on the digital header (next to Aref) instead of A4/A5, so it should be compatible with other boards as well. The buttons are just a voltage divider connected to an analog input, so that should work with the Leonardo as well.
    – tttapa
    Dec 26, 2017 at 9:58
  • 1
    I had not seen that.
    – Majenko
    Dec 26, 2017 at 13:15

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