BluetoothSerial.readFromDevice() comes back empty

[gilbertocortez]

Hello,

I am trying to read a smart bicycle trainer (Tacx Flux 2), and I am able to pair to the trainer, but then when I try to read from the device it comes back empty. I tried to set the reader on an interval as well, to see if maybe by moving the trainer it would update the value but still nothing. Trainer does send info to other apps like Zwift or Tacx App. Please help, here is my code:

Thank you for the help!

import React, { useState, useEffect } from 'react'
import { StyleSheet, Text, View, Button, PermissionsAndroid, FlatList } from 'react-native'
import BluetoothSerial from 'react-native-bluetooth-serial'
import KeepAwake from 'react-native-keep-awake'

const IndoorTrainer = () => {

PermissionsAndroid.check(PermissionsAndroid.PERMISSIONS.ACCESS_COARSE_LOCATION)
.then(result => {
if (!result) {
PermissionsAndroid.request(PermissionsAndroid.PERMISSIONS.ACCESS_COARSE_LOCATION);
}
});

// Initial states
const [bluetoothDeviceInitialState, setbluetoothDeviceInitialState] = useState({
isEnabled: false,
loading: true
});
const [bluetoothDeviceState, setbluetoothDeviceState] = useState({
discovering: false,
connected: false,
devices: [],
unpairedDevices: []
});

// Use effect when enable button is clicked
useEffect(() => {
if (bluetoothDeviceInitialState.isEnabled === true) {
console.log('new try -------------------------');
console.log('Bluetooth has been enabled');
console.log(bluetoothDeviceInitialState);
console.log(bluetoothDeviceState);
afterEnable();
} else console.log('Bluetooth is not enabled');
}, [bluetoothDeviceInitialState]);

// Options completed after bluetooth is enabled
const afterEnable = () => {
BluetoothSerial.on('bluetoothEnabled', () => console.log('Bluetooth enabled'))
BluetoothSerial.on('bluetoothDisabled', () => console.log('Bluetooth disabled'))
BluetoothSerial.on('error', (err) => console.log(Error: ${err.message}))
console.log('completed afterEnable()');
}

// After discover devices button is clicked
const discoverUnpaired = () => {
//console.log('Start discovering devices');
if (bluetoothDeviceState.discovering === true) {
console.log('cancel on discoverUnpaired()');
return false
} else {
console.log('Start discovering bluetooth devices');
setbluetoothDeviceState({
discovering: false,
connected: false,
devices: [],
unpairedDevices: []
});

  BluetoothSerial.discoverUnpairedDevices()
    .then((unpairedDevices) => {
      console.log('Found devices, adding to state');
      //console.log(unpairedDevices);
      setbluetoothDeviceState({
        discovering: false,
        connected: false,
        devices: [],
        unpairedDevices: unpairedDevices,
      })
    })
    .catch((err) => console.log(err.message))
}

}

useEffect(() => {
console.log("Bluetooth devices updated");
//console.log(bluetoothDeviceState.unpairedDevices);
}, [bluetoothDeviceState]);

// Request bluetooth to be enabled
const requestEnable = () => {
BluetoothSerial.requestEnable()
.then((res) => setbluetoothDeviceInitialState({
isEnabled: true,
loading: false
})
)
.catch((err) => console.log(err.message));
}

/**

• Connect to bluetooth device by id
• @param {Object} device
  */
  const connectToBluetoothDevice = (device) => {
  console.log(Trying to connect to device ${device.name})
  BluetoothSerial.connect(device.id)
  .then((res) => {
  console.log(Connected to device ${device.name})
  console.log(bluetoothDeviceState)
  })
  .catch((err) => console.log(err.message))
  }

/**

• [android]
• Pair device
  */
  const pairDevice = (device) => {
  console.log(Trying to pair to device ${device.name})
  BluetoothSerial.pairDevice(device.id)
  .then((paired) => {
  console.log(Pairing to device ${device.name})
  if (paired) {
  console.log(Paired to device ${device.name})
  console.log(bluetoothDeviceState)
  } else {
  console.log(Device ${device.name} pairing failed)
  }
  })
  .catch((err) => console.log(err.message))
  }

/**

• Disconnect from bluetooth device
  */
  const disconnect = (device) => {
  BluetoothSerial.unpairDevice(device.id)
  BluetoothSerial.disconnect()
  .then(() => console.log('Device disconnected'))
  .catch((err) => console.log(err.message))
  }

const readFromBluetoothDevice = () => {
console.log('Reading from device')
BluetoothSerial.readFromDevice().
then((data) => {
console.log('Device read')
console.log('Data: ' + data)
})
.catch((err) => console.log(err.message))
}

return (

Bluethoot App
<Button
title='Request enable'
onPress={() => requestEnable()} />
<Button
title='Read from device'
onPress={() => setTimeout(readFromBluetoothDevice, 3000)} />
<Button
title='Discover devices'
onPress={() => discoverUnpaired()} />

  <FlatList
    data={bluetoothDeviceState.unpairedDevices}
    ItemSeparatorComponent={
      () => <View style={{ width: 16, backgroundColor: 'pink' }} />
    }
    renderItem={({ item }) => (
      <View>
        <Text>Device:</Text>
        <Text>{item.name}</Text>
        <Text>{item.id}</Text>
        <Text>{item.address}</Text>
        <Text>{item.class}</Text>
        <Button
          title='Connect to device'
          onPress={() => connectToBluetoothDevice(item)} />
        <Button
          title='Pair to device'
          onPress={() => pairDevice(item)} />
        <KeepAwake />
        <Button
          title='Disconnect devices'
          onPress={() => disconnect(item)} />
      </View>
    )}
    keyExtractor={item => item.id}
  />
</View>

)
}

export default IndoorTrainer

const styles = StyleSheet.create({})

[qingjiaowochengzd]

me too

[ambojialur]

This code is not working for me

BluetoothSerial.readFromDevice()
        .then(data => {
          console.log('Data: ' + data);   
        })
        .catch(err => console.log(err.message));