LED Blink Codes
The LaunchPad itself has two usable LEDs (red and blue), however, they can be
hidden below the J1 BoosterPack. Therefore we are using three additional LEDs
(red, yellow, green) that can be connected to the GPIOs 12 (red), 13 (yellow)
and 22 (green) and the 3.3V pin:
The red LED is synchronized with the red on-board LED, the green LED is
synchronized with the blue on-board LED.
The three external LEDs are used to visualize some important states of
Green (or Blue) LED
System is disabled.
System is enabled. Both motors are disabled.
Slow Blinking (1 Hz)
System and at least one motor are enabled.
Fast Blinking (4 Hz)
Same as above + at least one motor is currently aligned.
While the motors are aligned with the encoders, they are not yet ready to be
used. The motor position is locked (do not move manually!) and current commands
are ignored. Alignment is automatically started when motors are enabled for the
first time and it takes a few seconds. See Motor Alignment Calibration for more
The yellow LED indicates that CAN messages sent by the board are not
acknowledged by any receiver.
This means that there is a problem with the CAN connection (e.g. cable not
plugged in, driver not loaded, etc.). Depending on the CAN driver on the
computer, it may also only mean that currently no program is running that is
processing the messages (i.e. when using PCAN-USB on Windows).
The LED is turned off as soon as a message is acknowledged and will be turned
on again when sending of a message fails. So if the yellow LED is blinking
this indicates an unstable CAN connection.
Some error occured. More descriptive error code should be sent in the CAN
Note that an error usually disables the system and prevents it from being
re-enabled until the error is resolved.