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Published 1 month ago • verified publisher icon Ralim

"DC Low" with PD-chargers [State 25]

Open derhagen opened this issue 11 months ago • 4 comments

Describe the bug I have a Lenovo 65W charger (up to 3.25A@20V, as indicated in the PD debug menu) and a UGREEN 100w charger (up to 5A@20V). With both of them my pinecil shows me a "DC Low" warning when I try to solder. The little PD debug menu indicates PD "State 25", which I can't find any documentation on. All my working chargers report State 12, however. I tried different cables, the cable is definitely not the issue.

Details of your device:

  • Device: PinecilV1
  • Release: V2.23 RC1 (but similar problems before)
  • Power adapter being used: see above

derhagen avatar Jan 13 '25 15:01 derhagen

Hello, A PD state of 25 would mean that the charger is not negotiating as expected, and has not communicated. So the system has assumed it's not a valid PD charger. https://github.com/Ralim/usb-pd/blob/main/include%2Fpolicy_engine.h is the numbers.

If you take a video of connecting the iron in the debug mode, what numbers do you see the state go through ?

Also, I assume your seeing an input voltage of 5V on this charger rather than the expected 20V?

Ralim avatar Jan 13 '25 16:01 Ralim

If you take a video of connecting the iron in the debug mode, what numbers do you see the state go through ?

They both turn from "State 6" to "State 25 No VBUS"

Yes, I get 5V indeed.

Can I generate PD logs somehow? Both chargers work perfectly fine with different laptops and for fast-charging phones, so I guess it's a bug in IronOS.

derhagen avatar Jan 13 '25 17:01 derhagen

Can I generate PD logs somehow?

Not trivially, and getting stuck in that state means that IronOS hasn't seen any valid PD announcements from the charger.

I have a bunch of the Lenovo chargers and haven't seen this behaviour.

It could be that IronOS is too slow. Normally it waits until tip detection has completed before doing any negotiation as it needs to know what tip is fitted. I have pondered if we should instead negotiate 5V and then re-negotiate to raise the voltage. I could probably make a test firmware for this case if your will to do a bit of testing?

Ralim avatar Mar 04 '25 10:03 Ralim

I could probably make a test firmware for this case if your will to do a bit of testing?

I'd be happy to help with testing!

derhagen avatar Mar 04 '25 12:03 derhagen