How it communicates

The three channels

Every time you tap Send (on an entry, a table row, a layer, a fire allocation or a unit status), the app first asks where it should go. There is always an explicit Cancel, so nothing is sent over the radio or the internet by accident.

Channel A: share

It opens Android's standard share menu with ready-made text that describes the entry. From there you send it wherever you like: SMS, email or any messaging app on the phone.

• It is always available, even with no bridge or server connection.
• It does not go through the IRIS 3 network and needs no Network Key. Delivery depends on the app you picked, so it needs whatever network that app uses.

Channel B: over the radio

This is the field channel. It sends data digitally through the Bluetooth bridge and your radio, to every other device on the network. It is a broadcast, not a recipient choice: everyone who is connected and has the same key receives it.

What happens on the way

1. Phone to bridge

   The phone talks Bluetooth Classic to the bridge (an ESP32 with a MAX3232 on a serial link to the radio). See the Hardware and radio page.

2. Encryption with the Network Key

   Communication through the bridge is encrypted with the Network Key. Devices with a different key cannot exchange data.

3. 255-byte pieces

   Every message is split into pieces of up to 255 bytes, and the total cannot exceed 255 pieces. That is why the file limit is 60 KB.

4. Acknowledgement and retry

   The app waits for an acknowledgement (ACK Timeout, default 2 s) and retries (default 3 times) before giving up. If even one piece of a file is lost, the whole file is sent again from the start.

Setup step by step

1. Set the same Network Key everywhere

   Settings → NETWORK KEY. With no key, nothing is sent or received. If it differs on even one device, that device is left out.

2. Pair the bridge in Android

   Bluetooth pairing is done first in Android's own Bluetooth settings, not inside IRIS 3.

3. Device Connection

   Pick the bridge from AVAILABLE DEVICES and press CONNECT. System Status reads ONLINE when connected, SYNC while connecting and OFFLINE when not.

4. Test with Network Check

   Press Network Check and see who answers (below).

Channel C: via server

It sends over the internet through the rendezvous server to one specific recipient, never to the whole network. As soon as you pick it, a second window “Choose recipient” opens with your Known Devices and Groups.

• Known device: an IRIS 3 device you have paired with a QR code.
• Group: a member list you build from your Known Devices. The message reaches exactly those members. Only the creator sees Edit and Delete.

Setup step by step

You need a server that is already running (see Setting up a server) and its address, e.g. https://iris3.example.org.

Connecting the app to the server

1. Open Communication Setup

   On the Android device: Settings → “Communication Setup”. Alternatively, from the header icon on the map, with a long press → “Settings”.

2. Network Key

   In the first step of the screen enter the shared encryption key that all the devices of your network use, and press “Save”. Without it, the connection step stays locked. The same key goes on every device: the server does not send it, it is set locally.

3. Add or choose a server

   In the connection step open the “Server” dropdown, press “Add new server” and fill in Name (e.g. “Main”) and Address in the form https://host:port. The address is saved in the list so you can pick it again later.

4. Connect

   Press the connect button in the top status strip for the server. When the indicator turns “connected”, the app has an active channel to the server and is ready to pair.

Pairing devices

You can pair as many devices as you like, not just two: repeat the steps for each new device. All of them must already be connected to the same server with the same network key. An expired code is rejected, and you cannot pair with your own device.

1. One device creates a code

   In the “Create code” step press the button. A QR code appears, with a matching text code and an expiry countdown. The code expires after a few minutes. If it expires before it is scanned, press the same button again for a new one.

2. The other scans the code

   In the “Scan code” step the camera opens full screen (grant camera permission if asked). Scan the first device's QR.

3. Name the new device

   After a successful scan, the app asks for a name for the device you just paired (e.g. “Platoon 2”). Type it and press “Save”.

4. Confirmation

   A success message appears. Close the dialog. The device now shows in “Known Devices” and can be put in a group or receive messages and fire distribution.

What you can send

Network check

A one-tap “radio check”. Your device sends a request and every other device on the network answers automatically with its call sign, after a short random delay so they do not all answer at once. The result shows as a diagram or a table.

In Settings you can turn off the automatic answer (radio silence) and set the answer window, which is 7 seconds by default.

If nothing arrives