Dropouts - related to under-voltage?

Getting around to trying to solve a long-standing problem.
rasptouch running current release of ropieeexl.
As a roon endpoint seems very stable - no dropouts
When used as the audio out of my mac (over ethernet), sometimes plays well for hours, sometimes skips, hisses, and has dropouts.
Looking at the dmesg output I see some under-voltage errors.
(I bought a linear power supply after checking the spec with audiophonics.fr)
Think this could be related? Somewhere I have the original power supply and I could try that…if I could find it!


[ 4.810732] systemd-journald[152]: Received request to flush runtime journal from PID 1

[ 5.070055] rpi-ft5406 rpi_ft5406: Probing device

[ 5.074214] input: FT5406 memory based driver as /devices/virtual/input/input0

[ 5.228927] snd-rpi-simple soc:sound: ASoC: CODEC DAI pcm1794a-hifi not registered - will retry

[ 5.243770] snd-rpi-simple soc:sound: pcm1794a-codec <-> 3f203000.i2s mapping ok

[ 7.032093] random: crng init done

[ 7.032228] random: 7 urandom warning(s) missed due to ratelimiting

[ 7.198853] Under-voltage detected! (0x00050005)

[ 11.357166] Voltage normalised (0x00000000)

[ 36.315044] Under-voltage detected! (0x00050005)

[ 40.472909] Voltage normalised (0x00000000)

[ 46.709903] Under-voltage detected! (0x00050005)

[ 55.025779] Voltage normalised (0x00000000)

[ 631.187876] rpi_firmware_get_throttled : 1 callbacks suppressed

[ 631.187885] Under-voltage detected! (0x00050005)

[ 635.347806] rpi_firmware_get_throttled : 1 callbacks suppressed

[ 635.347812] Voltage normalised (0x00000000)

[ 6074.587626] Under-voltage detected! (0x00050005)

[ 6080.827595] Voltage normalised (0x00000000)

[ 6082.907674] Under-voltage detected! (0x00050005)

[ 6089.147691] Voltage normalised (0x00000000)

[ 9005.339137] Under-voltage detected! (0x00050005)

[ 9011.569090] Voltage normalised (0x00000000)

[ 9013.649178] Under-voltage detected! (0x00050005)

[ 9017.809111] Voltage normalised (0x00000000)

[12720.234876] Under-voltage detected! (0x00050005)

[12726.474762] Voltage normalised (0x00000000)

[12728.554875] Under-voltage detected! (0x00050005)

[12732.714810] Voltage normalised (0x00000000)

[12751.434992] Under-voltage detected! (0x00050005)

[12757.674959] Voltage normalised (0x00000000)

[17997.228996] Under-voltage detected! (0x00050005)

[18003.468969] Voltage normalised (0x00000000)

[18030.509227] Under-voltage detected! (0x00050005)

[18034.669202] Voltage normalised (0x00000000)

[54779.652460] cfg80211: Loading compiled-in X.509 certificates for regulatory database

[54779.664882] cfg80211: Loaded X.509 cert ‘sforshee: 00b28ddf47aef9cea7’

[root@ropieeexl ~]# tail -f /var/log/messages

Yes. You should find the original power supply or purchase a replacement power supply to test it.

Is your LPS rated for 3A?

Yes 7v 3 amps.

One thing to note is that the microUSB is only rated to 2.5A specification IIRC - I wonder with some power hungry HATs and a display etc that these power supplies might be adequate but the connection spec is perhaps not able to keep up. at least on the RPi 3’s I have noticed this low power issue quite often.

1 Like

What RaspTouch device is it?

RASPTOUCH LVDS Streamer I2S HDMI Audio-GD Compatible IIS

Audiophonics had me open the rasptouch and check the voltage coming out of the built-in power regulator. It’s 5.18V which is what they want (5.1V is what they want) so it doesn’t seem to be the power supply.
However I’ll try to find the original supply and see if it too has that error.
Still not clear if the under voltage could be causing the dropouts / oddness though…

The under voltage message can lead to all kinds of erratic behaviour, so I seriously suspect this could be your issue.

OK. The very device I am considering buying! If all three ancillaries are being fed through the Pi it may be that 5.1v is not enough. The SMPS I use is 5.3v and I have no under-voltage issues although mine is only Pi and screen.

I’m chatting with them but no resolution yet.