Ideally, this troubleshooting guide will develop to be a flowchart of things to check.
Power[]
Symptoms
- nothing is happening
- strange things are happening
- could be caused by low voltage
- motors appear to have no coherent signal
- could be caused by no MUX power
- some motors aren`t working
- could be caused by low voltage
Check
- is there proper voltage at the power pins on the chips, DB9s, and other connectors furthest from the power source
- if not, look for broken traces, blown fuses, broken wires; trace both ways using the multimeter
Motors[]
Symptoms
- jittery response
- see Noise for tips on noise reduction
- could be caused by no MUX power
- could be caused by overlaying signal and power lines, creating interference
- could be low voltage
- no response
- something is broken
Check
- are motor control signals actually being sent
- are any wires broken
- is the RC transmitter fully charged (maybe the rechargeable batteries dont provide enough power)
- is everything powered
- does the motor work, check when it`s plugged in directly to the Pololu or RC receiver
- if this doesnt work, make sure the controller isnt broken before tossing the motor
- does the motor controller work, check a known good motor with the Pololu and RC receiver directly
- if this works, it`s likely a MUX problem, either a broken trace or a power issue
Sensors[]
Symptoms
- no data is returned
- is it plugged in to power, and proper signal port
- is a proper level-shifter used, connected the right way
- data is frequently failing it`s checksum
- data path is being corrupted
- data appears to be wrong
- is the orientation of the sensor correct
- are all the proper sensor pins connected
- sensor does not respond when talked to
- is the voltage level of the signals compatible, ie RS485 level, use a scope to see
Check
- are the signal wires overlayed with power wires, which will cause Noise
- does the sensor`s connection show the proper voltage for power
- are the voltage levels on the RS232/TTL board correct? Reference RS232 Converter
Circuit Boards[]
Symptoms
- usually shown through other symptoms, ie no data, no power
- heating up
Check
- broken traces, wrong pins connected, use the Datasheets to confirm layout, missing components