The manual says on page 6 and 7:
“…
D+: DP, positive data signal
D-: DM, negative data signal
Mode display: The product will automatically recognize the fast charge
mode, temporarily identifying only the QC2.0 and CQ3.0 modes. Other
mode recognition is temporarily not supported.
…”
For sure, “temporarily” should be read here as “until now”.
Which QC mode(s) the L5 power supply and the L5 are supporting and with which protocol this is negociated?
Librem 5 does not support QC protocols (especially when Qualcomm® Quick Charge™ technology not translated wrongly).
For our interest here, this document is very important initial document (prior to recent ones, and latest one defining PD3.1), let me sort it as historical one, official one that belongs to this thread: https://www.usb.org/sites/default/files/USB_Type-C_Compliance_Document_rev_1_2.pdf. It defines our environment. Therefore please go back to this post:
Some good PD orientation link (with important table): https://www.pshinecable.com/article/what-are-the-differences-between-usb-pd3-1-and-usb-pd2-0-pd3-0.html.
On the other side following document belongs to this thread only partially (USB-IF certified controllers related) and therefore not belonging in general to the Librem 5 category: https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/quick-charge-device-list.pdf. Anyway, this document is for certain important as very present in our modern, technical surrounding.
P.S. No unnecessary comments of mine this evening (I hope). And might post this weekend some photo of QC3.0 charging typical Android smartphone. Also, as almost certain, your USB gadget is actually dedicated QC charging protocol tester (support for QC2.0, QC3.0 charging protocols is broad/mature one).
This will not happen (but still load latest firmware there) while USB testers (its hardware, see two links I already provided as well) that can read all charging protocols are rare (just first two in this linked selection): https://ae01.alicdn.com/kf/H69802b84951f45c8b010635c3d281199B.jpg.
EDIT: I just found (and can order it) C0+ bidirectional one (I do not project any need for other or better one), currently not too expensive:
*C0+ has an introductory table and only provides simple protocols − as translated from above link.
Who knows what that actually means.
I think what this may mean in practice is: It only identifies those modes correctly. PD 3.0 will work (if the phone and charger both support it, as is the case here) but it will be misidentified on the screen of the USB meter.
EDIT: Today afterwards you brought me lough over myself. Thanks therefore!
