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KB: Using bus powered USB peripherals with the pinephone keyboard mounted - Printable Version +- PINE64 (https://forum.pine64.org) +-- Forum: PinePhone (https://forum.pine64.org/forumdisplay.php?fid=120) +--- Forum: PinePhone Accessories (https://forum.pine64.org/forumdisplay.php?fid=123) +--- Thread: KB: Using bus powered USB peripherals with the pinephone keyboard mounted (/showthread.php?tid=16922) |
KB: Using bus powered USB peripherals with the pinephone keyboard mounted - docsunset - 06-26-2022 From megi: https://xnux.eu/pinephone-keyboard/faq.html#safety Quote:Can I plug something to the phone's Type-C port? I'm wondering if anyone knows, or has advice where to ask around, about how to "make *absolutely sure* the phone will not enable its power output to the USB device." Is this something that can be achieved through sysfs? Or a udev rule? Or would it require hacking on the kernel? Has it already been done in any distros? I've just installed Arch ARM (https://github.com/dreemurrs-embedded/Pine64-Arch) and am hoping to use the pinephone with a teensy 4.1 microcontroller attached via USB along with the keyboard, but I would like to avoid frying either the pinephone, teensy, or keyboard. RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - zetabeta - 06-26-2022 source (pinephone (pro) keyboard): https://www.pine64.org/2022/05/31/may-update-worth-the-wait/ short version: do not connect anything to the pinephone usb type-c port, when keyboard case is mounted. regardless does it draw power or insert power. problem seems to be that pp's usb port is controlled by hardware chip, which seems to be more or less buggy. and that hardware chip starts to insert 5 volts when usb devices are connected, thus resulting dual power supply issue. maybe software can be fixed but hardware overrides are usually not possible. this or these issues should re-thought in next pinephone. RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - wibble - 06-27-2022 See also https://wiki.pine64.org/wiki/PinePhone_(Pro)_Keyboard#Safety which links to the pine64 blog post where it was discussed. No ways to "make *absolutely sure* the phone will not enable its power output to the USB device" have been identified so far. RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - docsunset - 06-29-2022 Is this also an issue if the keyboard is turned off by double clicking the physical button on the side? RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - wibble - 06-30-2022 Yes - from the blog post linked above: "To be fair, it is possible to turn the PPKB’s 5 V boost output off, both in software that talks to the battery charging IC inside the PPKB and by using the physical button on the PPKB itself, but it was concluded empirically that the inactive status of the charging part of the PPKB achieved that way simply cannot be trusted, because the charging part may become active again unexpectedly. Moreover, nothing gets electrically disconnected that way, which still ends up in a USB charger plugged into the phone’s USB port feeding power into the charging part of the PPKB, which in this case may be even worse for the health of the charging part, because there is now no power coming out of the PPKB to “fight against” the power coming in from the USB charger. Not good at all." It seems to be a fundamental hardware problem that's going to need a redesign, unfortunately discovered after people had bought them. RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - docsunset - 06-30-2022 Ok, so it's a hardware problem that demands a hardware solution. If I were to e.g. remove the battery from the keyboard, or desolder the charging chip, or otherwise modify the hardware, is there some way I could continue to use the keyboard while circumventing this power issue? I would rather be able to use USB peripherals with the phone than have a backup battery in the keyboard, if it is possible to make that choice. My aim in this scenario would be to guarantee that the phone could not be damaged by the keyboard while a USB peripheral is connected to the phone. Might it be possible to install a hardware switch somewhere inside the charger so that I could maintain both functions? E.g., naïvely considering the schematic, could I cut the trace from pins 16 and 17 of the IP5209 power management SOC to jumper 2, or intercept the trace from jumper 2 to wherever it's going, and splice in a physical switch? Also, my sincere thanks to all who have responded. Your input is very much appreciated. I see here for instance that it has been suggested by reddit user u/Odd-Version9895 that it should be safe to use the phone's usb port if the battery is disconnected, but I don't know on what authority that person is able to make that claim. It makes sense to me intuitively, but what do I know... RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - theResonant - 01-09-2023 (06-30-2022, 10:46 AM)docsunset Wrote: Might it be possible to install a hardware switch somewhere inside the charger so that I could maintain both functions? E.g., naïvely considering the schematic, could I cut the trace from pins 16 and 17 of the IP5209 power management SOC to jumper 2, or intercept the trace from jumper 2 to wherever it's going, and splice in a physical switch? I thought of the very same thing, but didn't get the chance to try it: https://forum.pine64.org/showthread.php?tid=16853 However, someone went one step further - they spliced a USB port instead of a switch, so they could charge other devices: https://forum.pine64.org/showthread.php?tid=17015 (but somehow this doesn't work anymore due to software reasons...) RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - undata - 05-02-2023 (06-26-2022, 12:50 PM)docsunset Wrote: From megi: https://xnux.eu/pinephone-keyboard/faq.html#safety Something could be a usb bus. The manual for the keyboard says it is okay to do that. But it don't work... RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - Ephraimbogan - 07-26-2023 (06-26-2022, 12:50 PM)docsunset Wrote: From megi: https://xnux.eu/pinephone-keyboard/faq.html#safety Does this problem persist even when the keyboard is disabled by double-clicking the physical button on its side? RE: KB: Using bus powered USB peripherals with the pinephone keyboard mounted - mikeb - 08-07-2023 Dear friend, if you have a moment of free time - please look at https://forum.pine64.org/showthread.php?tid=18586 ( " USB mouse isn't working when a PP keyboard is attached? " ) |