Hello again!
I have managed to succesfully create code for my 4x4 keypad matrix to turn on relays, BUT as soon as I plug in my gsm/gprs shield to arduino, something goes wrong - I think that gsm shield and keypad module doesn't work with each other and I dont know how to fix that. So the thing is as soon as plug in the GSM shield keypad doesn't work AT ALL! And let's say when I press 'C' or 'D' on keypad the blue light on the GSM shield lights up and it seems that the shield just restarts. I upload my code so you can take a look at it. Please, maybe someone knows how to make them work together or maybe I am missing something?
Thanks!
SMSSender.ino (4.17 KB)