Some recent questions have shown an interest in how ROS can be used to run a motor or read a sensor on a custom robot. Many hobby robots have one or more microcontrollers that interface with the robot hardware. These microcontrollers should be able to communicate using a serial connection to a robot mounted laptop running ROS.
The avr_bridge is a sophisticated approach, but it requires a larger AVR processor and C++ code development on the microcontroller which may not be available in some circumstances. Is there a simpler alternative?