Sending String command to BLE in Ionic

Question

im new in ionic, right now i'm trying to send a "code" in string. which the string consist of a few packets data in HEX. eg. V1-FC03-2ED1-FE01

V1 is the sequence, then after the first - is the first packet "FC03" the code successfully send to my arduino using serial monitor on pc. arduino serial monitor

now i want to send it trough BLE using ionic. i follow the example on github on doing the BLE. it works if send 1 or 0.

here is the function in ionic codes that going to send to arduino after button pressed

onPowerSwitchChange(event) {
console.log('onPowerSwitchChange');
let value = this.power ? 1 : 0;
let buffer = new Uint8Array([value]).buffer;
console.log('Power Switch Property ' + this.power);
this.ble.write(this.peripheral.id, LIGHTBULB_SERVICE, SWITCH_CHARACTERISTIC, buffer).then(
  () => this.setStatus('Light is ' + (this.power ? 'on' : 'off')),
  e => this.showAlert('Unexpected Error', 'Error updating power switch')
);
}

here i tried to change

 let value = this.power ? 1 : 0;

to

 let value = "V1-FC03-2ED1-FE01";

but when compile, got error

Argument of type 'string[]' is not assignable to parameter of type 'ArrayBuffer'. Property 'byteLength' is
        missing in type 'string[]'.
  L68:  let value = "V1-FC03-2ED1-FE01";
  L69:  let buffer = new Uint8Array([value]).buffer;
  L70:  console.log('Power Switch Property ' + this.power);

hopefully someone can help me on this problem

Possible duplicate of [Converting between strings and ArrayBuffers](https://stackoverflow.com/questions/6965107/converting-between-strings-and-arraybuffers) — gre_gor, Aug 27 '18 at 18:11

score 0 · Answer 1 · answered Dec 17 '18 at 02:23

Not sure if this will help you as I'm not a programmer by trade... but I wanted to send a "2" as string and it turned out that I had to do it like this:

  var data = new Uint8Array(1);
  data[0] = 50;

With 50 being the Uint8Array equivalent of 2

Currently I'm trying to read from the BLE in the opposite direction to no effect so please keep us posted as to your progress.

Sending String command to BLE in Ionic

1 Answers1