How to use Low Byte Temp for VMB1TS?

For developers
1

I know how to find temperature by dividing High Byte by two (-63 to 63°C with step 0.5)
I would to know how to use Low Byte (4 bits at left) : 0.0625° x Value… but should I add it to first Value (High byte) ???

Thanks
David

2

Forget the low byte

If you receive command E6, take the first data byte after the command and run it through this code:

function ParseTemperature(Value: Byte): Double;
begin
  Result := Value;

  if Result >= $80 then
    Result := ($FF - Result + 1) * -1;

  Result := Result / 2;
end;

Numbers prefixed by the dollar sign “$” are hexadecimal numbers.

The “Result > $80” condition is for negative temperatures

Temperature precision is 0.5°C

3

After many tests and some help, here is a JavaScript code, to calculate temperature with decimal :

// Function to calculate temperature with high precision
function TempCurrentCalculation(msg) {
	// E6 (Transmit Temp) or EA (Sensor status)
	switch (msg[4]) {
		case 0xE6:
			return msg[5] / 2 - Math.round(((4 - msg[6]) >> 5) * 0.0625 * 10) / 10
		case 0xEA:
			return msg[8] / 2 - Math.round(((4 - msg[9]) >> 5) * 0.0625 * 10) / 10
		default:
			console.error("ERROR with TempCalculation", msg)
			return undefined
	}
}

Hope this will help other coders.

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