info-beamer

Low voltage detected


#1

How are you checking for “Low voltage detected”?

I have a 1.5A 5V power supply connected, but it seems that I keep getting the “Low voltage detected” alert.

My power supply is using a standard Barrel DC power connector and two USB cables are soldered to the connector - one going to the RPi and the other to the HDMI interface/screen.

The whole system draws max 600mA of power - so there is plenty of power left in the supply.

2019-02-28_13-41-42


#2

The voltage detection uses the built-in mechanisms for that. It basically calls

vcgencmd get_throttled

and checks if bit 16 is set in the result. According to the documentation

under-voltage occurs when voltage drops below 4.63V.

Did you set the cpu governor to anything other than powersafe [1]? Generally on a Pi3, a 2.5A power supply is recommended. See https://www.raspberrypi.org/documentation/faqs/#power

[1] I just realized the linked documentation is wrong: powersafe is the default. This will be updated soon.


#4

I have now connected the device with a HY3003 Gigimess power supply (3A max) - and I still have the problem.

[edit:] I suspect that it might have something with the splitting to do. I have another device on its own power without problems.


#5

Found the sollution: The used USB cable cannot provide enough power - so changing the wires to a thicker cable did solve the problem!

(PS: This is apparently my new account as LBWA account is closed)