I got the lightning symbol after update in the top corner alway on.
psu is 5v 2500mah.
wasnt on before update.
any clue how to fix it?
What Raspberry Pi do you have? Post your webconf page here.
what I found out is when using an original pi pst all works fine.
will I put my old one in that I used before and never had problems the
power symbol appears.
seams like change in code and testing vendor id of the pst.
had that some years ago under Debian although if I remember right.
We discussed this at Zynth Club tonight. The RPi3 does seem more susceptible to low voltage after the recent update. Maybe some tuning was changed in the upstream OS. I find that a good quality PSU and cable still gives me a stable device but slight detestation in the cable or connector and the low voltage (lightning bolt symbol) is displayed.
I measured the no name psu.
it is still over 2000mah.
rated 2500 mah on sticker.
so it cant be under voltage.
just my 1% of thought.
btw it worked fine for good two years until update today.
RPi is sensitive to low voltage which may occur if there is a drop on across the cable. If the impedance of the connection (cable, connectors, etc.) is significant then a voltage drop will occur that is directly related to the current draw, i.e. the more power the RPi draws, the lower the voltage at its input. Whilst the voltage at the PSU may remain at 5V, the RPi may get only 4.8V with 0.2V dropped across the power cable. The RPi3 is sensitive to fairly small drops in voltage. There is a configuration that allows this sensitivity to be tweaked as well as some changes to power handling but I found them of less use than just fixing the problem at source, i.e. using a good quality PSU with good quality interconnects (cable and connector). I have inserted a 5V UPS (which is like a power bank but with some bells and whistles) between the PSU and Zynthian V3 (with RPi3) which helps to smooth out the supply. Plugging the PSU directly into the Zynthian results in regular xruns and low voltage indication but adding the UPS stops this whilst still charging the battery. This indicates the RPi requires more peak power but less mean (average) power than the PSU can deliver. (A big capacitor would probably do something similar.) I have the added bonus that I can disconnect the PSU and go portable for a while (which was the main reason I bought the UPS). I have a short USB cable between the UPS and the Zynthian but that has started to play up a bit with low voltage indication if positioned in certain ways so it is likely broken and needs replacing. Such faults will develop overtime. A once good cable will become intermittent with reduced, but not completely failed performance.
So defo check your physical implementation but I do agree that there has also been changes which disadvantage the RPi3 (and possibly RPi4 which may cope better). These may relate to later kernel, changes or additions to the Zynthian code, changes in device drivers, etc. I have done some work on benchmarking (see elsewhere in forum) and want to see some profiling of the code but we have been occupied with other things so that hasn’t progressed as fast as we would like.
1 Like
Sounds more like a power bank when you mention mah (milliamp/hr)
it should be 2.5A or 2500mA or greater.
There are a lot of cheap power supplies out there. Sometimes its even the wire from the power supply not being the right gauge.