Xiaomi mi scale v1 Weight Data

Question

I am trying to writing an application that can take weight measurement from Xiaomi mi scale version 1. I get a hex value like this 0624b2070101002e3800004c04(5.50kg) from the Body Composition Measurement service.

According to my research the first byte gives 02:measurement unit The last two bytes are the weight value, But when I convert this value to decimal and divide by 200, I don't get the correct value.

Can someone help me get the correct data?

Answer 1

The last two bytes are 4c04. Bluetooth sends data in little endian format so as an integer that is 1100.

The "GATT Specification Supplement 4" document at https://www.bluetooth.com/specifications/specs/ says:

3.27.2.7 Weight field

This field is in kilograms with resolution 0.005 if the bit 0 of the Flag field is 0 or in pounds with a resolution of 0.01 if the bit 0 of the Flag field is 1.

1100 * 0.005 = 5.5kg

Answer 2

The value of hex 4c04 is equal to 19460 which does not give you the desired result. But changing the endianess (byte-order) to 044c results in a value of 1100 which, divided by 200, gives you the desired result of 5.5kg

Answer 3

I had a similar problem, here is how i do it personally read the whole thing i had everything documented and don't be intimidated by the looks of it it's pretty simple in fact:

for the conversion i use this website cause well I don't know how to convert :) enter link description here

here is an image showing exactly how it works u need to look to the INT 16 BIG endian and post the whole hex code not just the last two bytes like this: