Micro:bit BLE Keyboard

[espruino-discuss]

Posted at 2021-10-18 by coat

Hi again!
I'm trying to make a BLE keyboard with micro:bit to send a keystroke when it is tilted to the right, left, front, back.
This is my code (I've not finish to write all)

var kb = require("ble_hid_keyboard");
NRF.setServices(undefined, { hid : kb.report });

var min = -400;
var max = 400;


  var x = Microbit.accel().x*1000;
  var y = Microbit.accel().y*1000;
  var z = Microbit.accel().z*1000;

if (x > min && x < max && (y > min && y < max && z < (-800))){
  kb.tap(kb.KEY.A);
} else {
    if (x > min && x < max && (y > min && y < max && z > 800)) {
      kb.tap(kb.KEY.F);
    } else {
        if (x > min && x < max && (z > min && z < max && y > 800)) {
            kb.tap(kb.KEY.D);
        } else {
            if (x > min && x < max && (z > min && z < max && y < (-800))) {
                kb.tap(kb.KEY.E);
            } else {
                if (y > min && y < max && (z > min && z < max && x > 800)) {
                    kb.tap(kb.KEY.B);
                } else {
                    if (y > min && y < max && (z > min && z < max && x < (-800))) 
                        kb.tap(kb.KEY.C);
                }
            }
        }
    }
}

I'm using the example of BLE Keyboard here and I receive this error

Uncaught TypeError: Expecting a number or something iterable, got undefined
 at line 1 col 104
...0,0,0],function(){a&&a()})})
                              ^
in function "tap" called from line 16 col 18
  kb.tap(kb.KEY.A);
                 ^

or this one

>New interpreter error: UART_OVERFLOW
>Uncaught ReferenceError: "requirerage" is not defined
 at line 2 col 1
requirerage").write(".bootcde","85,\nPAD_MINUS:86,PAD_PLUS:8...
^
Uncaught SyntaxError: Got '}' expected ','
 at line 11 col 5
    }
    ^

If I make a test with just

print("A");

instead of

kb.tap(kb.KEY.A);

I've no error and the code works as I want.

What it can be?

[espruino-discuss]

Posted at 2021-10-18 by @fanoush

What it can be?

UART_OVERFLOW

The code is probably sent too fast to the device. As a workaround you can try to check Settings->Communication->Throttle Send. Then uploading will be slower.

---

Posted at 2021-10-20 by coat

Hi fanoush.
I tried your suggestion but UART_OVERFLOW error is still there :-(

---

Posted at 2021-10-20 by @fanoush

Oh, then I don't know. But it is pretty strange it didn't help because when throttle is enabled it is almost unbearably slow to upload anything so not sure how it could still overflow.

Also when thinking about it the Micro:bit 1 build it is pretty limited due to low RAM and flash memory. Can you just type NRF.sendHIDReport on left side if this method is even present? if not then the keyboard stuff won't work anyway and you would need custom build of Espruino to enable it.

Having the micro:bit v2 would be much much better.

---

Posted at 2021-10-20 by coat

I was not precise fanoush, sorry.
I am already using Micro:bit v2.
The code works correctly, but often I need to flash it many times until the error doesn't occur.