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weliem / blessed-android

BLESSED, a Bluetooth Low Energy (BLE) library for Android
MIT License
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Best method for writing to characteristic outside of callbacks #33

Closed phillipytran closed 4 years ago

phillipytran commented 4 years ago

Hi Martijn, I have been looking through your example app and I noticed that you only write to characteristics through callbacks in BluetoothHandler.java. If I want to write to a characteristic outside of a callback, like in response to a user pressing a button, what would be the best way to go about doing that? Currently, the best solution that I have thought of is to create a function within BluetoothHandler.java that uses getConnectedPeripherals, select the peripheral I want, and then use writeCharacteristic. Any help would be appreciated.

weliem commented 4 years ago

Hi, what you are doing is fine. You just need a reference to a peripheral. So you can use getConnectedPeripherals(), or getPeripheral(), or just keep track of it yourself.

Koxx3 commented 4 years ago

Hello, I would be very interested by an example ;) would it be possible please ?

phillipytran commented 4 years ago

Hi, Sorry for the late response. The way I did it was create a custom function inside my own BluetoothHandler class: fun writeCharacteristic(command: ByteArray){ macAddress?.let { mac -> val peripheral = central.getPeripheral(mac) Timber.d("MAC Address is valid") if (peripheral.getService(ROBO_BLE_UUID) != null) { Timber.d("Service is valid") peripheral.getCharacteristic( ROBO_BLE_UUID, ROBO_BLE_TXCHARACTERISTIC_UUID ).let { peri -> Timber.d("Writing characteristic") peri?.let { peripheral.writeCharacteristic(it, command, BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT) } } } } }

I use the MAC address of the peripheral (which is known by me since I know what I am interfacing with, then I get the characteristic that I want from the peripheral (also known), and then I directly use writeCharacteristic() for the BLEPeripheral class.