E750v2 OpenWRT oled MCU

Hi all,

I’ve got a new E750v2 test device and wanted to flash openwrt. It seems like the sock gl.inet Firmware for the E750v2 has a few different packages installed than the ones on the github repository. Seems like there are a few references in the mcu package for the oled screen which are missing on the e750-mcu package I found on github.

I also found this repository: GitHub - gl-inet/GL-E750-MCU-instruction: Gl-iNet E750 MCU instruction list
But it doesn’t compile with latest stable openwrt and hasn’t been updated for three years.

Reason for installing stock openwrt is that I want a debloated device to maximize battery life. Seems like the stock gl.inet firmware uses quite a lot of cpu in idle: (webui closed, connected via ethernet)
root@GL-E750:~# uptime
22:30:27 up 19 min, load average: 1.35, 1.54, 1.35

Stock openwrt (but without a working oled screen) gets almost down to 0 in idle and you can feel that the device is A LOT cooler.
What’s the best way to get a clean OpenWRT (I just need cellular+wifi+wireguard in luci) on the E750v2?

Many thanks!

Sounds like we are after the same thing! I would also love to get the OLED screen working with stock OpenWrt.

Just to warn you, don’t hope to use the 5 GHz wifi with your stock OpenWrt, currently… I have started a different thread about the problems with that.

Thanks for the warning!
To be honest the most critical thing for me is to have a battery indication one the oled screen. I can work around everything else, but without any indication about the battery status it gets a little bit tricky to use the device.

If there is any Idea how to get the oled screen to display battery information that would be great!

I haven’t used the MCU package, but I did try directly interacting with it via the serial port. I was able to set a custom display message by doing this:

echo ‘{“display_mask”: “2”, “custom_en”: “1”, “content”: “My Message, 16x4”}’ >> /dev/ttyS0

According to the github page, you should be able to read the battery status from the MCU as well, though I haven’t tried. By combining that with the arbitrary write, it might be possible to write a little cron script that would write ‘Battery: 99%’ or something to the screen once per minute.