each build stage is prefixed with a letter to make it appear in
order.
for example, =a_serial= contains the first build stage.
+** troubleshooting
+ to troubleshoot a misbehaving robot, go through these stages
+ in order until you find a stage that does not work correctly.
+
+ first, in =a_serial=, you'll check whether the arduino can
+ communicate over the serial connection with the computer.
+
+ in each stage, make sure the wires shown in the fritzing
+ diagram are correctly connected on your robot.
+ then load the corresponding arduino sketch to your robot
+ and either check the serial monitor, or turn on the motor battery.
+
+ this will help you pinpoint exactly where the problem lies on your
+ robot.