MCU communication on GL.iNet Mudi (GL-E750)

Hi guys,

I have OpenWRT snapshot r16997-6561ca1fa5 installed on my GL.iNet Mudi, and it seems to work just fine, but I can't seem to communicate at all with the on-board micro-controller.

According to the commit message , the instructions given by GL.iNet should work for the bare OpenWRT install.

But I can't seem to send any command that will update the OLED display, or power off the device. Sending messages to /dev/ttyS0 doesn't return any errors (sending messages to any other tty does return errors) but it also doesn't seem to do anything.

For example:
echo '{"poweroff": "1"}' >/dev/ttyS0
returns nothing and does not power off the device.

I'm not sure if this is just a feature that hasn't been released in a snapshot yet, or if there's something I'm missing.

Hope someone can help.

there's How to control the GL-E750 OLED

but it's not very helpful.

from the documentation linked from commit,

it seems communication with the MCU requires a package called gl-e750-mcu
and gives instructions to add this package to your custom openwrt compile.

Compile on the other openwrt source

$cd openwrt_root          #go to your openwrt source root
$cd package
$git clone
$cd ..
$make menuconfig
  gl-inet  ---> 
    <*> gl-e750-mcu........................................ GL iNet mcu interface
$make package/GL-E750-MCU-instruction/{clean,compile} V=s
$ls bin/packages/mips_24kc/base/gl-e750-mcu_2020-06-08-f8c77bdb-1_mips_24kc.i

That package is not present in OpenWrt core
or OpenWrt community packages

So if you want this to work you need to compile the package as instructed and then copy it to the router and install manually

It would be very good if someone could just copy the sources and contribute the package to the OpenWrt Packages feed so everyone else can use this without recompiling

@alzhao was this intentional? It would be better if one of your developers send this package to the package feeds since it's for your device. No problem, just asking. If you cannot do this someone else from OpenWrt community will send it.


As we write this package only for GL-E750, which is not a generic package, we don't know if this can be accepted by OpenWrt community directly. So we even didn't try to send the package.

But if someone else can do it instead, that will be very helpful.


In community package feeds it will be accepted. That is the place for all packages for optional functionality, specific or not specific.
It is only on github, it has no mailing list

1 Like

Did anyone add this package yet?

feel free to do it yourself ...

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