MobileRead Forums - View Single Post - KV charging issue at long-term usage

Eicca · 01-31-2021, 08:48 AM

Hello,
there is a problem occured during working on my alarm clock project (see other thread).
To my Voyage I have connected an USB-Speaker and a power connector with a y-otg-cable.

There are three files in filesystem (/sys/devices/system/...) to define the USB/charging-mode:
allow_charging
charging
mode

It is no problem to get the speaker and charging simultaneous to work.
mode 10 is otg-host: usb-port is powered by the kindle, speaker works without external power connector
mode 5 is otg-gadget: kindle can be charged. (allow_charging and charging have to be set to 1)

To protect the battery I keep the battery at 50%. If it is lower, I set to 1/1/5 (allow_charging/charging/mode). If it is at 50%, I set allow_charging to 0.

Now the problem: after some time the system do not observe the to these files written values anymore. So after half a day (or two or three days..) running the clock-script, charging stops and battery drains to zero.
I have checked, whether the files are set to the correct values and tried to "reset" the charging mode by setting to 0/0/10 and then 1/1/5 again, but nothing helped.

Do anyone have an idea how to solve this problem? My unwanted workaround would be rebooting the kindle with the script of my clock in autostart (not tested yet)..

01-31-2021, 08:48 AM	#1
Eicca Junior Member Posts: 6 Karma: 538 Join Date: Dec 2020 Device: KV, PW4	charging issue at long-term usage Hello, there is a problem occured during working on my alarm clock project (see other thread). To my Voyage I have connected an USB-Speaker and a power connector with a y-otg-cable. There are three files in filesystem (/sys/devices/system/...) to define the USB/charging-mode: allow_charging charging mode It is no problem to get the speaker and charging simultaneous to work. mode 10 is otg-host: usb-port is powered by the kindle, speaker works without external power connector mode 5 is otg-gadget: kindle can be charged. (allow_charging and charging have to be set to 1) To protect the battery I keep the battery at 50%. If it is lower, I set to 1/1/5 (allow_charging/charging/mode). If it is at 50%, I set allow_charging to 0. Now the problem: after some time the system do not observe the to these files written values anymore. So after half a day (or two or three days..) running the clock-script, charging stops and battery drains to zero. I have checked, whether the files are set to the correct values and tried to "reset" the charging mode by setting to 0/0/10 and then 1/1/5 again, but nothing helped. Do anyone have an idea how to solve this problem? My unwanted workaround would be rebooting the kindle with the script of my clock in autostart (not tested yet)..