About JanOS

Internet connectivity

JanOS can connect to the internet using both WiFi and cellular network. This article guides you through the configuration of both, and shows you how to connect the WiFi and cellular antenna.


To connect to WiFi and cellular you'll need a configuration file present. The easiest way to create this is to rename the file apps/system/js/local_settings.json.example to local_settings.json in the same folder. In here you can specify whether to enable WiFi, the name of the network and the password. If you have a network that does not require a password this field is ignored.

The same goes for the cellular section. You can configure the SIM PIN code, whether the use roaming, or limit data connectivity over 2G. A more in depth description is listed in Writing your first application.

From code you do not have to bother whether the board is connected through WiFi or cellular. You can subscribe to generic online and offline events which will fire regardless of connection type.

window.addEventListener('online', () => {
  console.log('We\'re online!');

window.addEventListener('offline', () => {
  console.log('Lost connection');

WiFi Antenna

There are two antennas that are essential for connectivity through JanOS. The first one is the WiFi antenna. On the phones we've seen so far this is always a paper antenna (like the one above) which is glued to the casing of your phone and connects with some copper colored points to the mainboard. If you want to use WiFi on the board, use the screwdriver approach to un-glue the antenna, and attach it to the mainboard with some anti-static tape.

Cellular antenna

The second antenna is the cellular antenna. On some phones, like the Spreadtrum based ones, and the ZTE Open C, the antenna is integrated on the mainboard. In this case you do not have to do anything. On other phones, the antenna is separate and connects to the mainboard. It should be easy enough to spot. Also remove the antenna from the casing, and connect the antenna again to the board. There is only one connection point for it, so shouldn't be too hard.

Antenna (C8680 GP) of the GeeksPhone Peak