# Vaikai Avakai Documentation

This doc explains the prototype implementation of the Avakai messaging feature.
There a 3 basic components:
The Avakai iOS App lets you discover and connect to Avakais via Bluetooth.
Once connected an Avakai will send a Bluetooth message to the iPhone triggered by a head touch.
This message will be received and forwarded by the app as a Push Notification using the Parse.com backend to
all other Avakais that are currently connected to the Internet. When a push notification is arriving in the app (using a hidden push notofication with the content-available: 1 property) the app will forward this message again through Bluetooth to the receiving Avakais.

These are the interesting parts in the code:

AppDelegate:
- (void)application:(UIApplication *)application
    didReceiveRemoteNotification:(NSDictionary *)pushData
    fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler

This will be called (even when an app is suspended) when a Push Notification arrives.
There are 3 types of messages to be handled:

AvakaiMessage: will be forwarded via Bluetooth to the Avakais
AvakaiConnected & AvakaiDisconnected indicates a new Avakai that connected via (another) iPhone to the internet. They will be listed in the app with a yellow Avakai.

ScanViewController:
sendPushNotification will send a Push Notification using Parse.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
When an local Avakai is selected it will either connect to it or if it is already connected it will send a direct “blink” message to the Avakai using Bluetooth
For Internet-connected Avakais (yellow) a push notification will be send to them.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
This takes care of the rendering of the Cell for each Avakai.

## Arduino Code

There weren’t many changes I had to do, except for handling messages with the command “99”.

        if (btdata[6]==99){ // Remote Push Notification
          sound(btdata[5]);
          RGBchange(btdata[0]);
          delay(300);
          RGBchange(0);
        }

This can be adjusted as required to trigger sounds, vibrations etc.

Parse Backend

Parse provides the Push Notification Infrastructure.