I have been using these RF modules(http://www.sparkfun.com/products/10532) to build a remote robot. The transmitter and reciver are controlled with two Arduino UNOs. I have a test where it reads a message transmitted from the transmitter(http://www.sparkfun.com/products/10534) and prints it on the screen. I have that part working somewhat perfectly. When a motor is attached(anywhere, even on 5V and gnd pins) the data gets completly messed up, no usable information. Does anyone know how I could fix this?
How is the motor connected exactly? How do you turn it on/off, change direction or vary RPM?
Is the motor powered through the same battery as the other electronics? Then the large current consumption could easily disturb the voltage levels of the other electronics. Maybe even a microcontroler reset.
If the motor generates sparks inside then those can create broadband RF noise disturbing the RF modules.
Basically we need a better idea of how your circuit looks like.
I had the two motors that came with the magician chassis(http://www.sparkfun.com/products/10825). I had these two motors controlled through the Ardumoto motor driver shield(http://www.sparkfun.com/products/9815).
The RF reciever was on a breadboard. The RF transmitter was controlled by another Arduino which got input from a joystick shield. It would transmit ‘F’ for Forward, ‘L’-Left, ‘B’-Back, ‘R’-Right, ‘S’-Stationary… Basic commands at this point. I had the reciever print to the serial monitor and it worked fine. On the actual robot the robot would be at a stand-still and would take the first command perfectly. Then it would ignore anything I did and just go crazy.
I then wired the reciever to the serial monitor again… worked. Then I attached a motor to +5V and GND… Data got messed up.
Long story short, wherever I attach the motor, it still messes up the reciever.
4xAA bateries with barrel jack powers the arduino. All other things powered through it. One motor draws 140-150ma(ish).
2 motors - 280ma(ish).