Telemetry (Sense Hat)

I have recently started trying out my Sense Hat module for the Raspberry Pi; it has a number of sensors built in to play with and support for reading and writing data through a Python library. There are a number of libraries out there, but I chose this one as it allowed me to recycle some of my old code.

I mostly just recycled the database creation and writing code for SQLite, and I am storing the data as a blob (JSON string) so that I can continue revising my data objects without having to mess around with my database at all.

I'm planning on calling this and processing the data through a service I'm working on as well.

	import logging
	import sqlite3
	import sys
	import time
	import json
	from sense_hat import SenseHat
	from re import findall
	from subprocess import check_output
	sense = SenseHat()
	rounding = 2
	logPath = '/home/pi/pyDev/SensorMgr/logs/'
	sqlite_file = logPath + 'SensorData.db'
	table_name = 'PiData'
	FORMAT = '%(asctime)s : %(levelname)s : %(message)s'
	logging.basicConfig(format=FORMAT, filename=logPath + 'debug.log', level=logging.DEBUG)
	try: # capture sensor data
	# system
	core_temp = check_output(["vcgencmd", "measure_temp"])
	core_temp = findall(b'\d+', core_temp)
	core_temp = core_temp[0].decode("utf-8")
	# time
	gmTime = time.gmtime()
	strTime = time.asctime(gmTime)
	timeStamp = time.time()
	# sense hat
	humidity = round(sense.get_humidity(), rounding)
	temp = round(sense.get_temperature(), rounding)
	pressure = sense.get_pressure()
	pressure = round(pressure / 10, rounding) # convert to kPa from millibars
	orientation_rad = sense.get_orientation_radians()
	# compass
	sense.set_imu_config(True, False, False) # gyroscope only
	north = round(sense.get_compass(), rounding)
	except: # catch *all* exceptions
	e = sys.exc_info()
	print("{msg}".format(msg=e))
	logging.debug(e[0], exc_info=True)
	try:
	# Open db connection
	conn = sqlite3.connect(sqlite_file)
	c = conn.cursor()
	except: # catch *all* exceptions
	e = sys.exc_info()
	print("{msg}".format(msg=e))
	logging.debug(e[0], exc_info=True)
	# create data obj
	myList = list()
	element = ["CoreTemp", core_temp, "C"]
	myList.append(element)
	element = ["Humidity", humidity, "%rH"]
	myList.append(element)
	element = ["Temperature", temp, "C"]
	myList.append(element)
	element = ["Pressure", pressure, "kPa"]
	myList.append(element)
	element = ["Orient", orientation_rad, "rad"]
	myList.append(element)
	element = ["Compass", north, "Deg N"]
	myList.append(element)
	dataStr = json.dumps(myList)
	print(dataStr)
	time_col = 'Time'
	date_col = 'DateTime'
	data_col = 'Data'
	try:
	# Create output sql strings
	sql_insert = "INSERT INTO {tn} ({tc}, {dc}, {dobc}) ".\
	format(tn=table_name, tc=time_col, dc=date_col, dobc=data_col)
	sql_values = "VALUES ({tc}, '{dc}', '{dobc}')".\
	format(tc=timeStamp, dc=strTime, dobc=dataStr)
	sql_string = sql_insert + sql_values
	print("SqlCmd: " + sql_string)
	except: # catch *all* exceptions
	e = sys.exc_info()
	print("{msg}".format(msg=e))
	logging.debug(e[0], exc_info=True)
	# execute the script, commit changes and disconnect
	try:
	c.execute(sql_string)
	conn.commit()
	conn.close()
	except: # catch *all* exceptions
	e = sys.exc_info()
	print("{msg}".format(msg=e))
	logging.debug(e[0], exc_info=True)
	# output to console
	print("Humidity: %s %%rH" % humidity)
	print("Temperature: %s C" % temp)
	print("Pressure: %s kPa" % pressure)
	print("p: {pitch}, r: {roll}, y: {yaw}".format(**orientation_rad))
	print("Core " + core_temp)
	print("North: %s" % north)

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