Danger!The device is undervolted!

RPI 3B with Justboom Hat Amp
Powered as per recommendation from Justboom via max 24V 6amp brick

That cannot be undervolted (because I can not put anything more into the Hat)


Unit shows this message ONLY without speakers connected. Once the correct speakers (per used power supply) are connected, the message goes away!


we are surfacing the detected undervoltage signal from the silicon as mentioned here: Raspberry Pi Documentation - Configuration
Regarding the involvement of balenaOS, the balenaOS just surfaces the undervoltage detected by the CPU itself.

We have some experience that RaspberryPis that run for a long time or have sit for a long time in the shelf show the undervoltage signal regardless of the given power supply. The situation that you say that connecting the speakers adds maybe a GND connection that is lacking from the RaspberryPi regulators. Please bare with me, as I’m no experience electrical engineer, and all I can give you are guesses.

Bet Regards

Hello, it looks like that HAT uses a class D audio amplifier chip. I’m not an electrical engineer either but my understanding is that some class D audio amplifiers expect a load (the speakers) to be connected at all times. So your experience when the speakers are not connected may be a result of that.