Teensy/Arduino & OpenWrt

Work in Progress...

TP-LINK 703 router, inside & out:

Background

Implementation

At the command prompt type: opkg update

Depending on the flavour of Arduino you're using type one (or more) of the following at the prompt:

opkg install kmod-usb-serial-ftdi              //this is for Duemilanoves etc which use the FTDI serial chip
opkg install kmod-usb-acm                       //this is for Uno & Teensy
opkg install kmod-usb-serial-pl2303        //I used this as an example of a cheap USB to serial adapter

When you connect your Teensy/Arduino a new device should appear in /dev:



In my example here the new device is ttyACM0 - it shows up when I connect my Teensy

Install Serial to Net (ser2net)

At the prompt type: opkg install ser2net

Choose a TCP port for ser2net (eg 1234) to use, and add a line (or two) to the end of the file /etc/ser2net.conf as follows:

1234:raw:0:/dev/ttyUSB0:9600       //for FTDI serial devices, eg Arduino Duemilanove, Seeeduino etc.  Also for the PL2303
1234:raw:0:/dev/ttyACM0:9600      //for eg Teensy, Uno

If you're going to use more than one device at the same time assign different port numbers for each.

You can edit using vi, or simply append to the file by typing (eg) at the prompt:

echo 1234:raw:0:/dev/ttyACM0:9600 >> /etc/ser2net.conf

When you're done, the end of ser2net.conf should look rather like this:




Install a test program on your Teensy/Arduino. My example program below simply sends some data repeatedly to the serial port. If all is well this will be passed to TCP port 1234 of OpenWrt.

//test program to dump data
unsigned long int i;

void setup() {
  // initialize serial comms:
  Serial.begin(9600);
    delay(10000);  //just to give me time to open putty
}

void loop() {
  Serial.println("Arduino & openWRT test program");
  Serial.print("This is my arduino sending data through openWRT - it works with a hub...  ");
  Serial.println(i);
  i+=1;
  delay(50);      
}

Plug in your Teensy to the USB port of the router and start ser2net by typing ser2net at the prompt. It doesn't seem to matter in which order you do this.

Use (eg) PuTTY make a connection to port 1234 of your device.



Make sure that you click the Raw radio button... We said 'raw' in the ser2net.config file...

With a bit of luck you should see data coming from your Teensy when the window opens:




Clearly we have a bi-directional connection so lets give the Teensy something to do. I installed Bitlash for this. I don't use Bitlash a lot but I do find it useful for twiddling bits on the Arduino. I may use it more in future as it has evolved into something very clever! Quoting from the Bitlash site:

Bitlash is an open source interpreted language shell and embedded programming environment for the popular and useful Arduino. The Bitlash interpreter runs entirely on the Arduino and interprets commands that you type in a terminal window or send programmatically to the serial port.

// This is the simplest bitlash integration.

#include "bitlash.h"

void setup(void) {

	// initialize bitlash and set primary serial port baud
	// print startup banner and run the startup macro
	initBitlash(9600);

	// you can execute commands here to set up initial state
	// bear in mind these execute after the startup macro
	// doCommand("print(1+1)");
}

void loop(void) {
	runBitlash();
}

Gotchas

Conclusion

• A Teensy 3.0 - ttyACM1 churning out data on port 1235
• A PL2303 - ttyUSB0 - a USB-serial device wired in loopback echoing what is typed on port 1233
• A Teensy 2.0 - ttyACM0 running the Arduino Bitlash on port 1234

Smoke & Mirrors

Addendum 1

Addendum 2

opkg install kmod-video-core
opkg install kmod-video-uvc
opkg install mjpg-streamer

http://192.168.1.x:8080/?action=stream
http://192.168.1.x:8080/?action=snapshot

Wireless (IP) Programming Arduino with USB/IP

usbip -l 10.0.0.112

TP-LINK 703 device.
Here is my Canon scanner as it appears to the client on my W7 desktop:



To my delight this worked perfectly! I guess there's not a lot of point to an embedded scanner but it was sitting on my desk and I know that it's reliable.
I'm more interested in applying this to remotely program Arduinos etc so here is an Arduino as it appears to the client:



To use a device we need to attach it with usbip:



At this point I should have my remote Arduino attached. Let's take a look:



Device Manager tells us that we have a new COM Port, COM12. Let's try it:



You can't see this, but I've programmed an Arduino which is connected through USB/IP. It's in another room of my house but it could be absolutely anywhere. Believe me, it works!
It works flawlessly too! In the above I've actually used a Seeeduino which is essentially a Duemilanove clone, however I've also tried it with a standard Duemilanove and it works just as well.
The bad news is that my preferred development platform is the Teensy. Connecting a Teensy tells me this:



Attaching tells me this:



Windows does give me that reassuring 'bing' to tell me that a USB device is attached but it doesn't work, the Teensy loader just asks me to press the button, and even if I do this it still doesn't work.
I've tried it with Teensy 2.0 and Teensy 3.0 and neither will play.

I did most of this on a Friday night and had that 'devil may care' attitude brought on by a couple of beers. Perhaps an Arduino Leonardo will work?
The nearest I have to a Leonardo is a Chinese Pro Micro clone which I bought purely because it was so cheap!

Plugging it in reveals:



It's listed but attaching it doesn't seem quite right... Notice that the Receive Sequence isn't there... It seems that usbip has hung...
However, device manager has found a nice new COM port:



And this is seen by the Arduino environment too:



Let's give it a whirl! What is there to lose?



Haha! What indeed!? As I was writing this as I went along I lost the last 30 minutes of editing!
This seems to happen quite consistently so I had no trouble reproducing it to take the photo!

Conclusions

(Mr Teensy) at PJRC  will sort it.
USB/IP is interesting. It works extremely well with a bog standard Arduino but it clearly has some limitations.

I also need a real application to show this off properly, actually I do have a real application for this but it's rather dull so we'll stick to something more fun! How about an Arduino controlled robot which I can program over WiFi?
I had a magician robot lying around so here it is with my TP-Link router on board - you can see the blue top of the case through the chassis plate, the USB on the Seeeduino connects to it for reprogramming. I'll hook up my webcam (described above) when I get a moment.