Can I customize the blink function? (It does not shine in CM3)

Product support balenaOS
1

There is a blink feature for identifying terminals.
On the Raspberry pi, the board’s LED flashes.
However, the Raspberry pi CM3 has no LED. We have attached the power supply LED in GPIO.
If you can customize the call of Blink, you can blink it with GPIO, etc.
Is it possible?

2

Hey @Keisuke, what do you use as a base board / carrier board for the Raspberry Pi CM3? In the case of the Compute Module, the LED is on the base board, and the LED action depends on the specific carrier board. For example our balenaFin has an LED that is blinked, and the balenaFin variant of the OS sets the correct device to use for the blink action.

As I checked, both for the Raspberry Pi 3 device type, and the balenaFin device type the blink device is /sys/class/leds/led0/brightness (which is set in the LED_FILE variable of /etc/resin-supervisor/supervisor.conf).

In your case it really depends on the hardware you use, and would appreciate if you can provide some more information on that, before we can give any more advice.

Also, what balenaOS version / device type are you flashing on the CM3 you have? In general the blink action is fixed for a device type, as not expected that an OS version is flashed on another device type it is not created for.

4

Hello @imrehg

Thank you for answering.
We are connecting to our own custom boards.
The LED indicating that the power supply attached to the main unit is ON is connected to GPIO.

Is it possible to blink the LED connected to GPIO by rewriting the indicated file?

5

Hi,
What balenaOS version / device type are you flashing?
Kind regards,
Theodor

7

hello
It is as follows.

OS: balenaOS 2.32.0 + rev1
Device type: Raspberry Pi 3

8

Hi there, in that case you should be able to edit the file mentioned above as my colleague suggested. It is likely that you’ll need to modify the /etc/resin-supervisor/supervisor.conf file before it is flashed to the device.