Hi, I am pretty new to Arduino and to this forum, so I hope that someone can help me out here. I have two Arduino Uno boards, one that is connected to a server via USB and another one that is simply connected to a 12v power supply and which has a Adafruit motorshield attached so it can drive 2 stepper motors. For my project, I am trying to get a coded High - Low signal sequence from the first board's digital pin 5 to a digital pin 3 (or analog pin if that would work better) on the second board. The sketch I have running on the second board (the one with the motor shield) will decode the High-Low signal sequence (each High and Low is set to last 1 second) and then responds in steering the appropriate Stepper motor for the right steps into the desired direction.
I have tried to make the most simple connection by connecting digital out pin 5 on the first board to digital pin (input) 2 on the second board. However that leaves very erratic signals and the input 2 does seem to do its own thing. I have since found out that I need to use a pull-up or pull-down resistor, but I have no idea on how to wire that setup. I also presume that I need to do something about a common ground, but again, I have no idea what to connect to what.
Just as a background, the first board is connected to a server that runs HomeSeer home automation software and the sketch that is running on that board is specific to communicate with HomeSeer. That seems to work fine and I can use HomeSeer script to turn pin 5 on and off at the desired coded signals, I now just need to make that board sends its signals to the second board with the motorshield so it can decide the signal and operate my steppers. The software bit I can do fine, it is just the wiring that is a headache. I do have 10K resistors which I believe I may need for the pull up/down method, but any guidance on how to connect my pin 5 to an input on the other board would be very much appreciated.
Harry van der Vossen