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import sys
import time
from argparse import ArgumentParser
from bluepy import btle # linux only (no mac)
from colr import color as colr
# BLE IoT Sensor Demo
# Author: Gary Stafford
# Reference: https://elinux.org/RPi_Bluetooth_LE
# Requirements: python3 -m pip install --user -r requirements.txt
# To Run: python3 ./rasppi_ble_receiver.py d1:aa:89:0c:ee:82 <- MAC address - change me!
def main():
# get args
args = get_args()
print("Connecting...")
nano_sense = btle.Peripheral(args.mac_address)
print("Discovering Services...")
_ = nano_sense.services
environmental_sensing_service = nano_sense.getServiceByUUID("181A")
print("Discovering Characteristics...")
_ = environmental_sensing_service.getCharacteristics()
while True:
print("\n")
read_temperature(environmental_sensing_service)
read_humidity(environmental_sensing_service)
read_pressure(environmental_sensing_service)
read_color(environmental_sensing_service)
# time.sleep(2) # transmission frequency set on IoT device
def byte_array_to_int(value):
# Raw data is hexstring of int values, as a series of bytes, in little endian byte order
# values are converted from bytes -> bytearray -> int
# e.g., b'\xb8\x08\x00\x00' -> bytearray(b'\xb8\x08\x00\x00') -> 2232
# print(f"{sys._getframe().f_code.co_name}: {value}")
value = bytearray(value)
value = int.from_bytes(value, byteorder="little")
return value
def split_color_str_to_array(value):
# e.g., b'2660,2059,1787,4097\x00' -> 2660,2059,1787,4097 ->
# [2660, 2059, 1787, 4097] -> 166.0,128.0,111.0,255.0
# print(f"{sys._getframe().f_code.co_name}: {value}")
# remove extra bit on end ('\x00')
value = value[0:-1]
# split r, g, b, a values into array of 16-bit ints
values = list(map(int, value.split(",")))
# convert from 16-bit ints (2^16 or 0-65535) to 8-bit ints (2^8 or 0-255)
# values[:] = [int(v) % 256 for v in values]
# actual sensor is reading values are from 0 - 4097
print(f"12-bit Color values (r,g,b,a): {values}")
values[:] = [round(int(v) / (4097 / 255), 0) for v in values]
return values
def byte_array_to_char(value):
# e.g., b'2660,2058,1787,4097\x00' -> 2659,2058,1785,4097
value = value.decode("utf-8")
return value
def decimal_exponent_two(value):
# e.g., 2350 -> 23.5
return value / 100
def decimal_exponent_one(value):
# e.g., 988343 -> 98834.3
return value / 10
def pascals_to_kilopascals(value):
# 1 Kilopascal (kPa) is equal to 1000 pascals (Pa)
# to convert kPa to pascal, multiply the kPa value by 1000
# 98834.3 -> 98.8343
return value / 1000
def celsius_to_fahrenheit(value):
return (value * 1.8) + 32
def read_color(service):
color_char = service.getCharacteristics("936b6a25-e503-4f7c-9349-bcc76c22b8c3")[0]
color = color_char.read()
color = byte_array_to_char(color)
color = split_color_str_to_array(color)
print(f" 8-bit Color values (r,g,b,a): {color[0]},{color[1]},{color[2]},{color[3]}")
print("RGB Color")
print(colr('\t\t', fore=(127, 127, 127), back=(color[0], color[1], color[2])))
print("Light Intensity")
print(colr('\t\t', fore=(127, 127, 127), back=(color[3], color[3], color[3])))
def read_pressure(service):
pressure_char = service.getCharacteristics("2A6D")[0]
pressure = pressure_char.read()
pressure = byte_array_to_int(pressure)
pressure = decimal_exponent_one(pressure)
pressure = pascals_to_kilopascals(pressure)
print(f"Barometric Pressure: {round(pressure, 2)} kPa")
def read_humidity(service):
humidity_char = service.getCharacteristics("2A6F")[0]
humidity = humidity_char.read()
humidity = byte_array_to_int(humidity)
humidity = decimal_exponent_two(humidity)
print(f"Humidity: {round(humidity, 2)}%")
def read_temperature(service):
temperature_char = service.getCharacteristics("2A6E")[0]
temperature = temperature_char.read()
temperature = byte_array_to_int(temperature)
temperature = decimal_exponent_two(temperature)
temperature = celsius_to_fahrenheit(temperature)
print(f"Temperature: {round(temperature, 2)}°F")
def get_args():
arg_parser = ArgumentParser(description="BLE IoT Sensor Demo")
arg_parser.add_argument('mac_address', help="MAC address of device to connect")
args = arg_parser.parse_args()
return args
if __name__ == "__main__":
main()
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