Arduino Uno Connected Via USB to Netgear WGT634u Running OpenWrt

Posted by Max Power | Posted in Arduino, Netgear WGT634u | Posted on 28-11-2011-05-2008


In this post I will show you how I connected an Arduino Uno to my Netgear WGT634u running OpenWrt Backfire via the USB port.  One thing to note is that it is much easier to trouble shoot if you are connected to the router with a serial cable.  I have another post (here) that outlines the process for building and connecting to the router with a serial cable.


First we need to make sure that we have the USB drivers that we need:

opkg update
opkg install kmod-usb-ohci

Next we will install the drivers package that will support the Arduino:

opkg update
opkg install kmod-usb-acm

Now when you plug the Arduino into the WGT634u, you should see that it is recognized (you will only see this if you are connected to the router with the serial cable):

usb 2-1: new full speed USB device using ohci_hcd and address 3
usb 2-1: configuration #1 chosen from 1 choice
cdc_acm 2-1:1.0: ttyACM0: USB ACM device

We should be able to find a new addition for the Arduino in the following location:



Now that we have the Arduino installed, lets test it to see if we can send serial commands to it.  We can use the LED example included with the Arduino software to test it. Using your computer, upload the PhysicalPixel sketch from File > Examples > Communication > PhysicalPixel to the Arduino.  After you upload the sketch, plug it into the WGT634u and lets test it out.  In this example when we send a “H” the LED on the Arduino will light and when we send a “L” the LED will go off.

Turn off the led:

echo "L" > /dev/ttyACM0

Turn on the led:

echo "H" > /dev/ttyACM0

If this does not work for you, don’t fret…  It didn’t work for me either.  I appears that the older Arduino Uno boards reset the serial connection and so the light will flash but will not stay light.   I have a post (here) about how to fix this.


So now you have successfully connected your Arduino Uno to your Netgear WGT634u via the USB port and demonstrated that you can communicate with it via serial commands.

Comments posted (2)

Years later there still comes a thank you!

For those who just started with Arduino and openWRT like me (Router WDR4300 and Arduino uno r3) and landed on this page, the serial reset seems to be gone and the commands should have the “>” replaced with a “>” for example:
echo “H” > /dev/ttyACM0

At least it worked for me after getting “gt not found” and “permission denied”

Try send chmod 777 /dev/ttyACMO first

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