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BangleApps
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Refactored byte array conversions for efficiency and readability

master
jeffyactive 2021-12-17 16:28:30 -05:00
parent c93bbe4fb8
commit 00116b760c
1 changed files with 26 additions and 50 deletions
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76
apps/sensible/sensible.js
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@ -130,21 +130,9 @@ function transmitUpdatedSensorData() {
// Encode the bar service data to fit in a Bluetooth PDU
function encodeBarServiceData() {
let tEncoded = Math.round(bar.temperature * 100);
let pEncoded = Math.round(bar.pressure * 100);
let eEncoded = Math.round(bar.altitude * 100);
if(bar.temperature < 0) {
tEncoded += 0x10000;
}
if(bar.altitude < 0) {
eEncoded += 0x1000000;
}
let t = [ tEncoded & 0xff, (tEncoded >> 8) & 0xff ];
let p = [ pEncoded & 0xff, (pEncoded >> 8) & 0xff, (pEncoded >> 16) & 0xff,
(pEncoded >> 24) & 0xff ];
let e = [ eEncoded & 0xff, (eEncoded >> 8) & 0xff, (eEncoded >> 16) & 0xff ];
let t = toByteArray(Math.round(bar.temperature * 100), 2, true);
let p = toByteArray(Math.round(bar.pressure * 100), 4, false);
let e = toByteArray(Math.round(bar.altitude * 100), 3, true);
return [
0x02, 0x01, 0x06, // Flags
@ -157,24 +145,10 @@ function encodeBarServiceData() {
// Encode the GPS service data using the Location and Speed characteristic
function encodeGpsServiceData() {
let latEncoded = Math.round(gps.lat * 10000000);
let lonEncoded = Math.round(gps.lon * 10000000);
let hEncoded = Math.round(gps.course * 100);
let sEncoded = Math.round(1000 * gps.speed / 36);
if(gps.lat < 0) {
latEncoded += 0x100000000;
}
if(gps.lon < 0) {
lonEncoded += 0x100000000;
}
let s = [ sEncoded & 0xff, (sEncoded >> 8) & 0xff ];
let lat = [ latEncoded & 0xff, (latEncoded >> 8) & 0xff,
(latEncoded >> 16) & 0xff, (latEncoded >> 24) & 0xff ];
let lon = [ lonEncoded & 0xff, (lonEncoded >> 8) & 0xff,
(lonEncoded >> 16) & 0xff, (lonEncoded >> 24) & 0xff ];
let h = [ hEncoded & 0xff, (hEncoded >> 8) & 0xff ];
let s = toByteArray(Math.round(1000 * gps.speed / 36), 2, false);
let lat = toByteArray(Math.round(gps.lat * 10000000), 4, true);
let lon = toByteArray(Math.round(gps.lon * 10000000), 4, true);
let h = toByteArray(Math.round(gps.course * 100), 2, false);
return [
0x02, 0x01, 0x06, // Flags
@ -186,23 +160,9 @@ function encodeGpsServiceData() {
// Encode the mag service data using the magnetic flux density 3D characteristic
function encodeMagServiceData() {
let xEncoded = mag.x; // TODO: units???
let yEncoded = mag.y;
let zEncoded = mag.z;
if(xEncoded < 0) {
xEncoded += 0x10000;
}
if(yEncoded < 0) {
yEncoded += 0x10000;
}
if(zEncoded < 0) {
zEncoded += 0x10000;
}
let x = [ xEncoded & 0xff, (xEncoded >> 8) & 0xff ];
let y = [ yEncoded & 0xff, (yEncoded >> 8) & 0xff ];
let z = [ zEncoded & 0xff, (zEncoded >> 8) & 0xff ];
let x = toByteArray(mag.x, 2, true);
let y = toByteArray(mag.y, 2, true);
let z = toByteArray(mag.z, 2, true);
return [
0x02, 0x01, 0x06, // Flags
@ -211,6 +171,22 @@ function encodeMagServiceData() {
}
// Convert the given value to a little endian byte array
function toByteArray(value, numberOfBytes, isSigned) {
let byteArray = new Array(numberOfBytes);
if(isSigned && (value < 0)) {
value += 1 << (numberOfBytes * 8);
}
for(let index = 0; index < numberOfBytes; index++) {
byteArray[index] = (value >> (index * 8)) & 0xff;
}
return byteArray;
}
// Update acceleration
Bangle.on('accel', function(newAcc) {
acc = newAcc;