Add I2C and UART for GL-AR750s

Technical Support for Routers
1

Hello.

I own a GL-AR750S router.

I have been trying for a week to activate i2c and UART TTL without success.

How to enable i2C and UART on this router?

I am in version 3.201 (OpenWRT 07/19.7, ath79).

I have access to a computer running linux, windows, … but I don’t know where to start.

My final goal is to create an NTP service via GPS + pps associated with i2c sensors in order to have a measurement of the environment.

I already know how to do all this without worries via python3 on an RPI. But there I am blocked without having access to the i2c (for the capteurs) and the UART TTL (for the GPS)

thanks for your help !

2

What is wrong with UART TTL?

It should just works, right?

But if you want to connect GPS, you need to disable console output to the UART first

3

I think I understood how to activate i2c :

i install :

  • kmod-i2c-algo-bit
  • kmod-i2c-core
  • kmod-i2c-gpio
  • kmod-i2c-gpio-custom
  • kmod-i2c-smbus
  • kmod-regmap-i2c
  • libi2c

and enter at boot :

  • rmmod gpio_button_hotplug
  • insmod i2c-dev
  • insmod i2c-gpio-custom bus0=0,5,21

after that i see /dev/i2c-0

I wanted to install i2c tools but it conflicts with busybox. I would like to use the i2cdetect command. Do you have a solution ?

for the TTL UART I saw that there were ttySXX present. Only ttyS0 to work. I have not yet tried to communicate via this interface. How to deactivate the console @alzhao ?

I also saw that there was a 4 pin connector with the connector of a USB port (GND, DP, DM, VCC 5V) is it usable if we connect it to a USB port?

Thanks for your help as I really can’t find any info on this router.

4

I wanted to install i2c tools but it conflicts with busybox.
[Hoff] Please use opkg install i2c-tools --force-overwrite command to install the i2c-tools package.

How to deactivate the console
[Hoff] Please refer to OpenWrt Forum Archive

is it usable if we connect it to a USB port?
[Hoff] Yes, it is usabel.