About JanOS


You flashed your device with JanOS, now it's time to test some examples that come bundled with the OS. This guide does not require you to do any hard programming, but you will need to know how to connect the debugging tools. All the examples can be run from the debugging console.

Learn how to connect the debugger

Device Motion

The board contains a couple of sensors on which you can measure device motion. For example: the accelerometer or the gyroscope. This example logs the values on the Z-axis of the accelerometer to the console window. This is the axis on which you can measure gravity. For example, see what happens when you turn the board upside down.


// to stop

Security Camera

The security camera demo makes a photo on a set interval, and saves it to the internal storage of the device. When you're done with the camera, you can pull the images off the device through adb. If you have two cameras on the board, you can use 'front' instead of 'back' as well.

securityCam.start('back', 5000);

// it will now make a photo every 5s. and log a message
// when you're done:

Now you can grab the photos of the device via adb. Navigate to an empty folder, and run the following command:

$ adb pull /data/local/security/ .

Bluetooth doorbell

For this example you'll need a bluetooth speaker. We'll connect to the bluetooth speaker, and then use the proximity sensor (on the front top of your board) to detect when someone is close to the sensor. If that's the case we'll play a sound over the speaker. If you don't know the bluetooth address of your speaker, enable it and then run:


// Will log something like:
"Starting discovery"
"Found device" "00:0C:8A:75:EF:31" "Bose Mini Sou" "audio-card"
"Stopping discovery"

We now use the address that has been logged to start the demo:


// And to stop

Hover your hand over the proximity sensor to hear the doorbell sound playing.


This example uses a combination of APIs to make a tracking device. It connects to the internet, and registers with the push server. Whenever someone sends a push message to the device, the device will wake up, and sends it GPS location. First, we need to connect to a network. Connect to WiFi via:


// This will log something like:
"Wifi statuschange" "connecting" bootstrap
"Wifi statuschange" "associated"
"Attempting to connect to" "YOUR_NETWORK"
"Associated" "YOUR_NETWORK"
"Wifi connection succeeded"
"Wifi now has IP" ""

Now start the tracker, by running:

tracker.start('http://janjongboom.com:1339', 'YOUR_NAME');

// Log will look like:
"[Tracker] Creating"
"[Tracker] Post to" "http://janjongboom.com:1339/register"
"[Tracker] Registration succeeded, listening on" "XXX"

Now go to the tracker page to send a push message. This page is located at: http://janjongboom.com:1339/location/YOUR_NAME.

If you're here click the 'Request new location' button, and switch back to the console. After a second or two the following messages should appear:

"[Tracker] got push message!" Object {}
"autogrant permissions for" Object {}
"[Tracker] sendLocation" Coordinates {}
"[Tracker] sent location response" 200

If you go back to the tracker page you'll now see your current location shown on a map.

Note: if you see a message about a fake location and a map in Oslo, check the other messages in the console. Probably the GPS lookup failed because of a timeout.