This is a DRAFT page and not all details have been finalised or fully verified yet!


This page describes the operation of a BlinkM module connected to the PX4IO or PX4IOAR Board. Instead of an BlinkM module, a selfbuild CYZ_RGB module can be used or a Gemma Neopixel.


The BlinkM is a I2C controllable full-color RGB LED with 24-bit color control. It has a Two-Wire (aka “I2C”) interface, and up to 127 BlinkMs can be connected on a single two-wire network.

With the PX4 Autopilot the BlinkM can be used to monitor the Systemstate of the PX4 and indicates them with different blink and colorcodes. With this you are always informed about the flight-Modes, GPS satellites in use and battery warnings.


Be sure your BlinkM is set to address: 0x09 (default address of BlinkM devices)


The BlinkM must be connected to I2C3 port on the PX4IO or PX4IOAR extension board.

  • Pin 1 (I2C3) → VDD (BlinkM)
  • Pin 2 (I2C3) → C (BlinkM SCL)
  • Pin 3 (I2C3) → D (BlinkM SDA)
  • Pin 4 (I2C3) → GND

Start Script

FIXME new boot process

Add the BlinkM driver to the end of the Start Script.

# start the blinkm driver
blinkm start
usleep 5000
blinkm systemstate
# startup is done; we don't want the shell because we
# use the same UART for telemetry
echo "[init] startup done"

After startup, the Application checked how many lipo cells are connected to the System.
The recognized number off cells, will be blinked 5 times in purple color.
2 Cells = 2 blinks

5 Cells = 5 blinks
Now the Application will show the actual selected Flightmode, GPS-Fix and Battery Warnings and Alerts.

System disarmed:
The BlinkM should lit solid red.

System armed:
One message is made of 4 Blinks and a pause in the same length as the 4 blinks.

The first 3 blinks indicates the status of the GPS-Signal (red) and
the fourth Blink indicates the Flightmode:

GPS1 GPS2 GPS3 Mode Space Space Space Space Description
red red red off off off off 0-4 Satellites
red red off off off off off 5 Satellites
red off off off off off off 6 Satellites
off off off off off off off >=7 Satellites
white white white off off off off no GPS found
amber off off off off Mode : Manual
yellow off off off off Mode : Stabilized
blue off off off off Mode : Hold
green off off off off Mode : Auto
yellowyellowyellowyellowyellowyellowyellowyellow Battery warning
red red red red red red red red Battery critical
white white white white white white white white General error : no data from uOrb

BlinkM mounted on PX4:

BlinkM in action:

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