Model: BPI R1Firmware Version: OpenWrt Chaos Calmer 15.05-rc3 / LuCI Master (git-15.233.47308-791ca8b)Kernel Version: 3.18.19Other images on this same hardware had various methods to monitor the AXP209's battery port, so a script could check it every so often and provide a basic UPS service:If I remember right, an earlier version of OpenWRT had a sensors command that would print several things including the internal battery status.The Lubuntu image can read /sys/class/power_supply/battery/uevent.This wiki says that OpenWRT can read either of these files:/sys/devices/platform/sunxi-i2c.0/i2c-0/0-0034/axp20-supplyer.28/power_supply/battery/current_now/sys/power/axp_pmu/battery/amperageBut this OpenWRT image has no sensors command, and all of these paths have problems:/sys/class/power_supply/ exists, but is empty according to ls/sys/devices/platform/ exists and has stuff in it, but sunxi... isn't one of them/sys/power/state is an empty file, and the only thing in that directory (no axp_pmu)dmesg | grep axp returns:[    0.991670] axp20x-regulator axp20x-regulator: regulators node not found[    1.021570] axp20x 0-0034: AXP20X driver loadedDoes this image actually not have access to the AXP Power Management Unit?Or is there something missing such that the regulators aren't found despite the driver loading?
How to read the battery on a Banana Pi R1 router with OpenWRT?
power management;openwrt;battery;ups