Help getting started with programming on the Onion

Jeff Verive

I am a total newbie at the Onion AND at Linux. Are there any tutorials and/or videos available to show how to write, store, and run a program on this nifty device? I'm initially interested in reading from and/or writing to the GPIO pins. I have some familiarity with Python, but would also like to know how to program the Onion in Ruby. Thanks for ANY help y'all can provide.

Greg Ware

@Jeff-Verive , not much, but I've been writing down a cheat-sheet of my own exploration:

Connect at 115200 bps with TeraTerm
To setup wifi,
run wifisetup command
wifisetup -checkconnection
run ifconfig to verify
Web interface
root/onioneer
Upgrade F/W
run oupgrade -check
See https://onion.freshdesk.com/support/solutions/articles/6000069919-how-do-i-update-the-firmware-
Upgrading the firmware will delete/overwrite all of the files that are not in /etc or /usr
Most built-in linux commands redirect to /bin/busybox (multi-call binary)
Update packages list
opkg update
opkg list
Change Dock RGB LED
expled FF0000 -> red
expled 00FF00 -> green
expled 0000FF -> blue
expled 00FFFF -> cyan
expled FFFF00 -> yellow
expled FF00FF -> purple

This actually drives pwm GPIO on I/O pins 15,16,17:
fast-gpio pwm 17 200 0
fast-gpio pwm 16 200 100
fast-gpio pwm 15 200 0

To flash slowly:
fast-gpio pwm 15 2 80 -> blue
fast-gpio pwm 16 2 80 -> green
fast-gpio pwm 17 2 80 -> red
OLED expansion
Use oled-exp command
oled-exp -i power on
oled-exp write Hello
oled-exp -c power on cursor 3,6 write "zoulou was here"
oled-exp scroll diagonal-right
Run in background
To send to background, use Ctrl-z
bg command to resume
jobs command to list
fg %job_id to bring back to front
Or append & at the end of command to put in background directly
Mosquitto setup
opkg install mosquitto
opkg install mosquitto-client
[opkg install libmosquitto] -> done by install mosquitto-client

subscribe in background:
mosquitto_sub -v -t /test/#&
publish message:
mosquitto_pub -m 'Hello' -t /test/pub
Node.js setup
nodejs - 0.1-1 - Event-driven I/O server-side JavaScript environment based on V8
reports v0.10.5 (history says it is 2013-04-26), see https://nodejs.org/en/download/releases/

/usr/bin/node (or just node, since /usr/bin is in the path)

Test Node, copy this to hello.js
var http = require("http");
http.createServer(function (req, res) {
res.writeHead(200, {"Content-Type": "text/plain"});
res.end("Hello World\n");
}).listen(8000);
Run as node hello.js&

npm is supposed to be standard with node.js since 0.6.3, should have npm 1.2.18, not sure how to get it...

Boken Lin

Hi @Jeff-Verive, you can install ruby with these simply commands:

opkg update
opkg install ruby

However, we are still working on wrappers for the scripting languages. Currently we have finished the majority of the expansion drivers for python, and are working on wrappers for javascript and PHP.

Since you are already familiar with python, you can start writing program with the Omega by taking a look at these tutorials on our libraries: https://wiki.onion.io/pages/Tutorials/Libraries/. There is a section on how to use our Python library in each article.

Please let me know if it helps.

Greg Ware

I put that in better form on my blog here: link text

Boken Lin

Hi @Greg-Ware, we are still working on the npm because with many modules it requires the compilation of C/C++ code into binary. The Omega doesn't have enough computational resource to complete the compile itself, so we are working on a way to pre-compile some of the commonly used npm packages so that we can simply fetch it from a server during npm install.

Also your cheatsheet is super useful! Do you mind if we post it on the Wiki?

Thanks!

Vincent Bonnefille

Hey thanks for tips

[post edited]
to install node.js

opkg update
opkg install nodejs

Next step a piratebox ^^
Seeya

Boken Lin

Hi @Vincent-Bonnefille, yeah, you can install node without npm. You simply need to run the following commands:

opkg update
opkg install node