It is a good practice for lithium battery powered devices to briefly think about the charging configuration which can significantly influence the health and usable capacity over time of a battery. Typically, a LiPo battery -- as is also used in the Pinebook -- has a minimum voltage of 3.0 volts (falling below quickly damages the battery) and a maximum voltage of slightly above 4.2 volts (further charging can destroy the battery and even ignite a fire). 

The higher the difference of the battery voltage to these two extremes is, the longer it will keep its initial capacity and the less stress it has to withstand (temperature as another dimension can be critical also, but will be ignored for now). So, quite good voltage limits for charging your Pinebook may be 3.2 to 4.0 volts. The more tentative these limits are set, the less actual battery capacity will be usable, thus less time your Pinebook will be working on battery before it needs to charge.

Luckily, the power management unit AXP803 of the Pinebook allows you to configure, how you wish to set the voltage limits for your actual use case. To this end, you can use the virtual sysfs files in '/sys/class/power_supply/axp20x-battery/' which allow read and write access. I tested this on the current Armbian 5.86, but other distros may offer similar functionality, as they might use the same "axp20x" kernel module for accessing the AXP803 power management unit. 

With read access, you can find out how the limits are currently set. By echoing values into the virtual files, you can persistently write settings to the unit (yes, written values reside on the AXP803 and keep changed even after reboot or shutdown). As the AXP803, for instance, supports only four possible maximum voltages (4.10v, 4.15v, 4.20v, or 4.35v), invalid values as write attempts are caught by the operating system.

Hi,

Due to my external WiFi driver, I added,

Using armbian bionic mainline kernel on A64-v1.1 board
Linux pine64 4.19.38-sunxi64 #5.83 SMP Fri May 3 21:02:31 CEST 2019 aarch64 aarch64 aarch64 GNU/Linux

In RPI bionic could just set values in boot.txt.  Is this possible in armbian bionic mainline?

I know that one can use device tree overlays but can't find any examples specific to the A64.

Anyone have a dts file or otherwise know how to declare a pin as an interruptible input?  I've come across nothing in any A64 docs.

This is the software that came with my Pinebook 11.6" laptop but HDMI out doesn't work with XFCE or Plasma so I can't display on external screens. Everything else works well. Xubuntu is my preferred software so I don't want to install something else. How soon can this be fixed? Thanks

In my opinion, Armbian with LXDE as window manager is a good fitting combination for the limited power of the Pinebook. LXDE provides only few visual effects, so the system can be used with acceptable performance. Unfortunately, I had an issue with the battery plugin of the lxpanel (the bar where all current windows/processes are stacked into). 

Indication: Battery plugin (batt) of lxpanel does not show the current "capacity" (charged value in percent) of Pinebook's battery. Instead, it displays "0% charged" and continuously fires the low-battery alarm.

Reason: The integrated functionality of the battery plugin calculates the charged value by using the coulomb-based counters "charge_now" and "charge_full" (or alternatively "energy_now" and "energy_full"). These counters are usually provided by the power management unit's Linux kernel module. The kernel module (axp20x) for the AXP803 power management unit of the Pinebook does not provide "charge_now" and "charge_full" information. Instead, a percentage value for the current charge is provided as "capacity" (try 'cat /sys/class/power_supply/axp20x-battery/capacity').

Solution: I have changed the source code for the batt plugin with respect to the above mentioned reasons. Now, the percentage value is directly read from the corresponding sysfs file and not longer calculated indirectly.

The original code (lxpanel version 0.10.0) that you can find in 'lxpanel-0.10.0/plugins/batt/batt_sys.c' looked like this: 

Using armbian bionic mainline kernel on A64-v1.1 board
Linux pine64 4.19.38-sunxi64 #5.83 SMP Fri May 3 21:02:31 CEST 2019 aarch64 aarch64 aarch64 GNU/Linux

Need to allow non-root access to gpio pins (i.e. gpio group with access to export and unexport etc) via udev.  I've done this successfully before on an RPI but no matter what I try the gpio group and permissions are not set.   Maybe it's something specific to Pine64 so asking here.  

here is one version of rules I've tried.   using udevadm I've confirmed the file is read and loaded but the changes are not made

Hi,

there is a new driver coming to the 5.2 linux kernel called Panfrost https://gitlab.freedesktop.org/panfrost. Afaik Rockpro6 has a Mali GPU and maybe it could use these drivers. Are there any plans to backport them to the current kernel or to jump to a newer kernel in the near future?
Kodi for example supports Panfrost and should be running much better with it.

Greetings,
Khaosgrille

Hi!

I recently bought a RockPro64 with 4GB and would like to control a 1.8 LCD screen with SPI interface using the pins on the GPIO header.

The system is running ayufan's Ubuntu minimal. 

I had success in simple GPIO switching by using the RP64-GPIO library:
https://forum.frank-mankel.org/topic/292...-rp64-gpio

However, I was not able to access SPI. I could not find any help or documentation on the internet, not even on the Wiki.

Anyone had success with this?

I tested both current Armbian mainline images (Armbian_5.86_Pinebook-a64_Ubuntu_bionic_next_4.19.38_desktop and Armbian_5.86_Pinebook-a64_Debian_stretch_next_4.19.38) with my Pinebook 11.6" shipped in May '19 and both images have issues with the display brightness settings. 

Indication: After boot up, the backlight is set to maximum brightness and resetting it to other values in /sys/class/backlight/backlight/brightness (or via desktop power manager tool) shows no effect. The brightness level stays the same, although 'cat  /sys/class/backlight/backlight/brightness' returns changed values.

Solution: I managed to work around the issue by modifying the sun50i-a64-pinebook.dtb in /boot/dtb/allwinner/ in the following way:

(You can convert the dtb file to human-readable dts-format with 'dtc -I dtb -O dts /boot/dtb/allwinner/sun50i-a64-pinebook.dtb > converted.dts')

Initial content was:

I can mount it manually fine off the CLI but if I add it to /etc/fstab it hangs the entire system when booting. I've got it on fstab as