xiaomi_mi_scale/src/Xiaomi_Scale.py

#############################################################################################
# Code to read weight measurements fom Xiaomi Scale V2
# (Framework is prsent to also read from Xiaomi Scale V1, though I do not own one to test so code has not been maintained)
# Must be executed with Python 3 else body measurements are incorrect.
# Must be executed as root, therefore best to schedule via crontab every 5 min (so as not to drain the battery):
# */5 * * * * python3 /path-to-script/Xiaomi_Scale.py
# Multi user possible as long as weitghs do not overlap, see lines 117-131
#
# Thanks to @syssi (https://gist.github.com/syssi/4108a54877406dc231d95514e538bde9) and @prototux (https://github.com/wiecosystem/Bluetooth) for their initial code
#
# Make sure you set your MQTT credentials below and user logic/data through the environment variables
#
#############################################################################################



#!/usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import print_function
import argparse
import binascii
import time
import os
import sys
from bluepy import btle
import paho.mqtt.client as mqtt
from datetime import datetime

import Xiaomi_Scale_Body_Metrics

# Configuraiton...
MISCALE_MAC = os.getenv('MISCALE_MAC', '')
MQTT_USERNAME = os.getenv('MQTT_USERNAME', '')
MQTT_PASSWORD = os.getenv('MQTT_PASSWORD', '')
MQTT_HOST = os.getenv('MQTT_HOST', '127.0.0.1')
MQTT_PORT = int(os.getenv('MQTT_PORT', 1883))
MQTT_TIMEOUT = int(os.getenv('MQTT_TIMEOUT', 60))
MQTT_PREFIX = os.getenv('MQTT_PREFIX', 'miscale')
TIME_INTERVAL = int(os.getenv('TIME_INTERVAL', 30))
OLD_MEASURE = ''

# User Variables...
USER1_GT = int(os.getenv('USER1_GT', '70')) # If the weight is greater than this number, we'll assume that we're weighing User #1
USER1_SEX = os.getenv('USER1_SEX', 'male')
USER1_NAME = os.getenv('USER1_NAME', 'David') # Name of the user
USER1_HEIGHT = int(os.getenv('USER1_HEIGHT', '175')) # Height (in cm) of the user
USER1_DOB = os.getenv('USER1_DOB', '1988-09-30') # DOB (in yyyy-mm-dd format)

USER2_LT = int(os.getenv('USER2_LT', '55')) # If the weight is less than this number, we'll assume that we're weighing User #2
USER2_SEX = os.getenv('USER2_SEX', 'female')
USER2_NAME = os.getenv('USER2_NAME', 'Joanne') # Name of the user
USER2_HEIGHT = int(os.getenv('USER2_HEIGHT', '155')) # Height (in cm) of the user
USER2_DOB = os.getenv('USER2_DOB', '1988-10-20') # DOB (in yyyy-mm-dd format)

USER3_SEX = os.getenv('USER3_SEX', 'male')
USER3_NAME = os.getenv('USER3_NAME', 'Unknown User') # Name of the user
USER3_HEIGHT = int(os.getenv('USER3_HEIGHT', '175')) # Height (in cm) of the user
USER3_DOB = os.getenv('USER3_DOB', '1988-01-01') # DOB (in yyyy-mm-dd format)


class ScanProcessor():
	def GetAge(self, d1):
		d1 = datetime.strptime(d1, "%Y-%m-%d")
		d2 = datetime.strptime(datetime.today().strftime('%Y-%m-%d'),'%Y-%m-%d')
		return abs((d2 - d1).days)/365

	def __init__(self):
		self.mqtt_client = None
		self.connected = False
		self._start_client()


	def handleDiscovery(self, dev, isNewDev, isNewData):
		global OLD_MEASURE
		if dev.addr == MISCALE_MAC.lower() and isNewDev:
			for (sdid, desc, data) in dev.getScanData():
				### Xiaomi V1 Scale ###
				if data.startswith('1d18') and sdid == 22:
					measunit = data[4:6]
					measured = int((data[8:10] + data[6:8]), 16) * 0.01
					unit = ''
					if measunit.startswith(('03', 'b3')): unit = 'lbs'
					if measunit.startswith(('12', 'b2')): unit = 'jin'
					if measunit.startswith(('22', 'a2')): unit = 'kg' ; measured = measured / 2
					if unit:
						if OLD_MEASURE != round(measured, 2):
							print('')
							self._publish(round(measured, 2), unit, str(datetime.today().strftime('%Y-%m-%d-%H:%M:%S')), "", "")
							OLD_MEASURE = round(measured, 2)

				### Xiaomi V2 Scale ###
				if data.startswith('1b18') and sdid == 22:
					data2 = bytes.fromhex(data[4:])
					ctrlByte1 = data2[1]
					isStabilized = ctrlByte1 & (1<<5)
					hasImpedance = ctrlByte1 & (1<<1)

					measunit = data[4:6]
					measured = int((data[28:30] + data[26:28]), 16) * 0.01
					unit = ''
					if measunit == "03": unit = 'lbs'
					if measunit == "02": unit = 'kg' ; measured = measured / 2
					#mitdatetime = datetime.strptime(str(int((data[10:12] + data[8:10]), 16)) + " " + str(int((data[12:14]), 16)) +" "+ str(int((data[14:16]), 16)) +" "+ str(int((data[16:18]), 16)) +" "+ str(int((data[18:20]), 16)) +" "+ str(int((data[20:22]), 16)), "%Y %m %d %H %M %S")
					miimpedance = str(int((data[24:26] + data[22:24]), 16))
					if unit and isStabilized:
						if OLD_MEASURE != round(measured, 2) + int(miimpedance):
							print('')
							self._publish(round(measured, 2), unit, str(datetime.today().strftime('%Y-%m-%d-%H:%M:%S')), hasImpedance, miimpedance)
							OLD_MEASURE = round(measured, 2) + int(miimpedance)

			if not dev.scanData:
				print ('\t(no data)')

	def _start_client(self):
		self.mqtt_client = mqtt.Client()
		self.mqtt_client.username_pw_set(MQTT_USERNAME, MQTT_PASSWORD)

		def _on_connect(client, _, flags, return_code):
			self.connected = True
			sys.stdout.write("MQTT connection: %s\n" % mqtt.connack_string(return_code))

		self.mqtt_client.on_connect = _on_connect
		self.mqtt_client.connect(MQTT_HOST, MQTT_PORT, MQTT_TIMEOUT)
		self.mqtt_client.loop_start()

	def _publish(self, weight, unit, mitdatetime, hasImpedance, miimpedance):
		if not self.connected:
			sys.stderr.write('Not connected to MQTT server\n')
			exit()
		if int(weight) > USER1_GT:
			user = USER1_NAME
			height = USER1_HEIGHT
			age = self.GetAge(USER1_DOB)
			sex = USER1_SEX
		elif int(weight) < USER2_LT:
			user = USER2_NAME
			height = USER2_HEIGHT
			age = self.GetAge(USER2_DOB)
			sex = USER2_SEX
		else:
			user = USER3_NAME
			height = USER3_HEIGHT
			age = self.GetAge(USER3_DOB)
			sex = USER3_SEX
		lib = Xiaomi_Scale_Body_Metrics.bodyMetrics(weight, height, age, sex, 0)
		message = '{'
		message += '"Weight":"' + "{:.2f}".format(weight) + '"'
		message += ',"BMI":"' + "{:.2f}".format(lib.getBMI()) + '"'
		message += ',"Basal Metabolism":"' + "{:.2f}".format(lib.getBMR()) + '"'
		message += ',"Visceral Fat":"' + "{:.2f}".format(lib.getVisceralFat()) + '"'

		if hasImpedance:
			lib = Xiaomi_Scale_Body_Metrics.bodyMetrics(weight, height, age, sex, int(miimpedance))
			message += ',"Lean Body Mass":"' + "{:.2f}".format(lib.getLBMCoefficient()) + '"'
			message += ',"Body Fat":"' + "{:.2f}".format(lib.getFatPercentage()) + '"'
			message += ',"Water":"' + "{:.2f}".format(lib.getWaterPercentage()) + '"'
			message += ',"Bone Mass":"' + "{:.2f}".format(lib.getBoneMass()) + '"'
			message += ',"Muscle Mass":"' + "{:.2f}".format(lib.getMuscleMass()) + '"'
			message += ',"Protein":"' + "{:.2f}".format(lib.getProteinPercentage()) + '"'
			#message += ',"Body Type":"' + str(lib.getBodyTypeScale(getBodyType())) + '"'
			#message += ',"Metabolic Age":"' + str(lib.getMetabolicAge()) + '"'

		message += ',"TimeStamp":"' + mitdatetime + '"'
		message += '}'
		self.mqtt_client.publish(MQTT_PREFIX + '/' + user + '/weight', message, qos=1, retain=True)
		sys.stdout.write('Sent data to topic %s: %s' % (MQTT_PREFIX + '/' + user + '/weight', message + '\n'))

def main():

	sys.stdout.write(' \n')
	sys.stdout.write('-------------------------------------\n')
	sys.stdout.write('Starting Xiaomi mi Scale...\n')
	scanner = btle.Scanner().withDelegate(ScanProcessor())
	while True:
		try:
			scanner.scan(5, passive=True) # Adding passive=True to try and fix issues on RPi devices
		except:
			sys.stderr.write("Error while running the script, continuing. If you see this message too often/constantly there is probably a real issue...\n")
			pass
		time.sleep(TIME_INTERVAL)

if __name__ == "__main__":
	main()