Accessory makers can integrate their PTT button with Zello in a number of ways outlined in this article. The Bluetooth low energy integration (1) is the best way to ensure that your accessory can work with both iOS and Android. If your accessory only has Bluetooth 3.0 support, please see the Android integration steps using Bluetooth 2.0/3.0 (this version will not support iOS.
1. iOS and Android PTT Key Support Using Bluetooth v4.0/LE
For adding specialized PTT key support to Zello for iOS devices, Zello recommends Bluetooth 4.0 also known as Bluetooth LE. The feature is available on all Apple iOS 6 and above. LE is short for Low Energy, some compatible devices can be used daily for a year on before replacing batteries. Android devices can also use Bluetooth LE to trigger PTT on Zello.
To support Zello please implement the following:
1. Provide Zello with Advertised name, Services and Characteristics. They'll need to be added by Zello for testing. Even if you are able to see your device under the Zello wireless button options.
2. Implement one 'Notify' event on button press, and one notify event on button release.
1 = Pressed
0 = Released
To be clear, we don’t use continuous events sent while pressed or released.
The Zello iOS can discover devices using the TI CC256x chip, along with other chips if you supply UUIDs.
2. Android PTT Key Support Using Bluetooth 2.0/3.0
Zello Android supports specialized push-to-talk buttons like the Savox BTR-155 using the SPP protocol. The Zello app connects to an SPP socket and listens for the following ASCII commands:
For push-to-talk button pressed
For push-to-talk button released
Zello Blackberry and Windows Mobile apps also support these commands.
Zello will automatically recognize any PTT Bluetooth device with the word PTT in its advertised name. For example, if the name of the BT device is Best, it can be changed to BestPTT. It should then be available from Options > Under the hood > "PTT control device" drop-down menu.
You can contact Zello, if you do not have PTT in your advertised name and would like to be added to the list.
3. Android PTT Key Support from a Third Party Application
With the commands below you can:
- Trigger push-to-talk from your application
When the button is pressed:
Intent intent = new Intent("com.zello.ptt.down");
When the button is released:
Intent intent = new Intent("com.zello.ptt.up");
4. iOS PTT Key Support Using Apple MFi Hardware
For suppliers with an Apple licensed MFi hardware accessory, Zello iOS will support your hardware push-to-talk button using the ASCII serial control commands above for the control protocol "com.zello.control.ptt".
Get Listed as a Certified Zello Accessory
To support your device please implement the commands above and send a unit to Zello so we can confirm compatibility. After successfully testing, we’ll include your product in our list of supported devices.