Decoding Sens'it 3 Payload data - decode

Question

The sens'it 3 discovery payload pdf is not very detailed, and we can't figure how to decode the payload. Link to the payload discovery
This is the data we receive from Sigfox's backend: "b6096d6f", and when we try to decode the data according to the sens'it payload guide, we get values that don't match with sens'it's own platform.
How we attempt to decode the string. Current mode is set to temperature and humidity:
byte0 = b6 -> (182*0,05)+2.7 = 11.8 (We don't know what this value tells us. We know it's the volt level, but what can we use this for. The relevant data would be battery level in %)
byte1 = 09 -> 9 (which doesn't make sense according to the payload discovery pdf, as the mode value should be between 0-5)
byte2 = 6d -> (109 - 200) / 8 = -11.375 (Wrong when comparing to sens'its platform)
byte3 = 6f -> (111 / 2) = 55.5 (Correct when comparing to sens'its platform)
What we want to know is how to decode the payload into readable data.
We appreciate any help we receive. Thanks in advance!

Answer 1

Here is an example parser for sensit v3, it covers all modes and you can certainly get inspiration on how to convert battery voltage to percentage.
var payload,
battery,
mode,
humidity,
temperature,
light,
door,
vibration,
magnet,
alert,
eventCount,
firmwareVersion,
parsedData = [],
obj = {};
// Byte #0
var byte = parseInt(payload.slice(0, 2), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
battery = ((parseInt(byte.slice(0, 5), 2) * 0.05) + 2.7);
if (battery >= 4.15) {
battery = 100;
} else if (battery >= 3.8 && battery < 4.15) {
battery = Math.round((battery - 3.275) * 114);
} else if (battery >= 3.6 && battery < 3.8) {
battery = Math.round((battery - 3.56) * 250);
} else if (battery > 3 && battery < 3.6) {
battery = Math.round((battery - 3) * 16);
}
battery = battery < 0 ? 0 : battery;
// Byte #1
var byte = parseInt(payload.slice(2, 4), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
mode = parseInt(byte.slice(0, 5), 2);
switch (mode) {
case 0:
mode = 'Standby';
break;
case 1:
mode = 'Temperature & Humidity';
break;
case 2:
mode = 'Light';
break;
case 3:
mode = 'Door';
break;
case 4:
mode = 'Vibration';
break;
case 5:
mode = 'Magnet';
break;
default:
mode = 'Unknown mode {' + mode + '}';
}
alert = Boolean(parseInt(byte.slice(5, 6), 2));
// Standby mode
if (mode === 'Standby') {
// Byte #2
var byte = parseInt(payload.slice(4, 6), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
firmwareVersion = byte;
// Byte #3
var byte = parseInt(payload.slice(6, 8), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
firmwareVersion += byte;
firmwareVersion = parseInt(firmwareVersion.slice(0, 4), 2) + '.' + parseInt(firmwareVersion.slice(4, 10), 2) + '.' + parseInt(firmwareVersion.slice(10, 16), 2);
}
// Temperature & Humidity
if (mode === 'Temperature & Humidity') {
// Byte #1
var byte = parseInt(payload.slice(2, 4), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
temperature = byte.slice(6, 8);
// Byte #2
var byte = parseInt(payload.slice(4, 6), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
temperature += byte;
temperature = ((parseInt(temperature, 2) - 200) / 8).toFixed(2);
// Byte #3
humidity = parseInt(payload.slice(6, 8), 16) * 0.5;
}
// Light
if (mode === 'Light') {
// Byte #2
var byte = parseInt(payload.slice(4, 6), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
light = byte;
// Byte #3
var byte = parseInt(payload.slice(6, 8), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
light += byte;
light = (parseInt(light, 2) / 96).toFixed(2);
}
// Door
if (mode === 'Door') {
// Byte #1
var byte = parseInt(payload.slice(2, 4), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
door = parseInt(byte.slice(6, 8), 2);
switch (door) {
case 0:
door = 'The calibration of the Door mode has not been done';
break;
case 1:
door = 'Unused value';
break;
case 2:
door = 'Door is closed';
break;
case 3:
door = 'Door is open';
break;
default:
door = 'Unknown door status {' + door + '}';
}
}
// Vibration
if (mode === 'Vibration') {
// Byte #1
var byte = parseInt(payload.slice(2, 4), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
vibration = parseInt(byte.slice(6, 8), 2);
switch (vibration) {
case 0:
vibration = 'No vibration detected';
break;
case 1:
vibration = 'A vibration is detected';
break;
case 2:
vibration = 'Unused value';
break;
case 3:
vibration = 'Unused value';
break;
default:
vibration = 'Unknown vibration status {' + vibration + '}';
}
}
// Magnet
if (mode === 'Magnet') {
// Byte #1
var byte = parseInt(payload.slice(2, 4), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
magnet = parseInt(byte.slice(6, 8), 2);
switch (magnet) {
case 0:
magnet = 'No magnet detected';
break;
case 1:
magnet = 'A magnet is detected';
break;
case 2:
magnet = 'Unused value';
break;
case 3:
magnet = 'Unused value';
break;
default:
magnet = 'Unknown magnet status {' + magnet + '}';
}
}
// Event count (Door - Vibration - Magnet)
if (mode === 'Door' || mode === 'Vibration' || mode === 'Magnet') {
// Byte #2
var byte = parseInt(payload.slice(4, 6), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
eventCount = byte;
// Byte #3
var byte = parseInt(payload.slice(6, 8), 16).toString(2);
while (byte.length < 8)
byte = '0' + byte;
eventCount += byte;
eventCount = parseInt(eventCount, 2);
}
// Store objects in parsedData array
obj = {};
obj.key = 'mode';
obj.value = mode;
obj.type = 'string';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'firmwareVersion';
obj.value = firmwareVersion;
obj.type = 'string';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'temperature';
obj.value = temperature;
obj.type = 'number';
obj.unit = '°C';
parsedData.push(obj);
obj = {};
obj.key = 'humidity';
obj.value = humidity;
obj.type = 'number';
obj.unit = '%';
parsedData.push(obj);
obj = {};
obj.key = 'light';
obj.value = light;
obj.type = 'number';
obj.unit = 'lux';
parsedData.push(obj);
obj = {};
obj.key = 'alert';
obj.value = alert;
obj.type = 'boolean';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'door';
obj.value = door;
obj.type = 'string';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'vibration';
obj.value = vibration;
obj.type = 'string';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'magnet';
obj.value = magnet;
obj.type = 'string';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'eventCount';
obj.value = eventCount;
obj.type = 'number';
obj.unit = '';
parsedData.push(obj);
obj = {};
obj.key = 'battery';
obj.value = battery;
obj.type = 'number';
obj.unit = '%';
parsedData.push(obj);
//console.log(parsedData);
return parsedData;