datalogger.py

# Racing car data logger for SenseHat equipped Raspberry Pi
# By David Edwards (Dedward5)
#
# Find the project on GitHUb at https://github.com/Dedward5/motorsportdatalogger

import time


from sense_hat import SenseHat # for core sensehat functions #import this first so we can use sense hat display

sense = SenseHat()

sense.show_letter("!",text_colour=[0, 0, 0], back_colour=[255,0,0])  # prints ! on the matrix to indicate "starting up"

time.sleep(5) # added to dealy load for warmup


####################################### Configuration and  Settings ###############################

import configparser

configparser = configparser.RawConfigParser()   
configparser.read("options.cfg")

pi_camera_installed = configparser.get('video_options', 'pi_camera')
pi_camera_vertical_flip = configparser.get('video_options', 'flip_pi_vertical')
pi_camera_horizontal_flip = configparser.get('video_options', 'flip_pi_horizontal')
do_overlay_sensedata = configparser.get('video_options', 'overlay_sense_data')
do_overlay_gpsdata = configparser.get('video_options', 'overlay_gps_data')
chosen_path =  configparser.get('general_options', 'file_path')
usb_gps_installed = configparser.get('gps_options', 'usb_gps')
usb_mic_installed = configparser.get('video_options', 'usb_mic')
do_video_preview = configparser.get('video_options', 'video_preview')
launch_g = configparser.get('general_options', 'launch_threshold')
log_revs = configparser.get('general_options', 'rpm_input')


print ("Datalogger started")
print ("Configuration settings")
print ("Pi camera option = ",pi_camera_installed) # display the camera option setting on screen as a debug helper
print ("Pi camera vertical flip  = ",pi_camera_vertical_flip) # display the camera option setting on screen as a debug he$
print ("Pi camera horizontal flip  = ",pi_camera_horizontal_flip) # display the camera option setting on screen as a debug he$
print ("Overlay sense data on video = ",do_overlay_sensedata) # display the config option for video overlay of sense data
print ("Overlay GPS data on video = ",do_overlay_gpsdata) # display the config option for the video overlay of GPS data
print ("GPS installed = ",usb_gps_installed) # display the config option for the USB BPS
print ("USB Microphone = ", usb_mic_installed) 
print ("Video Preview =", do_video_preview)  
print ("Logs Revs =",log_revs)
print ("Launch Threshold =",launch_g)

FILENAME = ""
WRITE_FREQUENCY = 20



############################################ Libraries ############################################

 
import sys # revisit to see if needed
import os # used for the shutdown
# import time # used for time functions

from datetime import datetime # for date and time function

# Import and setup the camera if camera option set in config file


if pi_camera_installed == "yes":
	try:
		from picamera import PiCamera
		camera = PiCamera()

		if pi_camera_vertical_flip == "yes": 
			camera.vflip = True
		if pi_camera_horizontal_flip == "yes":
			camera.hflip = True
	except:
		pi_camera_installed = "no"		
		print ("Camera Error!")
		sense.show_message("Camera Error!",scroll_speed=0.02, text_colour=[255,0,0], back_colour=[0,0,0])



# Import and setup the GPS if GPS option set in the config file		
if usb_gps_installed == "yes":
	
	try:
		print("Installing GPS")
		from gps3.agps3threaded import AGPS3mechanism
		agps_thread = AGPS3mechanism()  # Instantiate AGPS3 Mechanisms
		agps_thread.stream_data()  # From localhost (), or other hosts, by example, (host='gps.ddns.net')
		agps_thread.run_thread()  # Throttle time to sleep after an empty lookup, default '()' 0.2 two tenths of a second
	except:
		usb_gps_installed = "no"
		print ("GPS Error, Check Connection!")
		sense.show_message("GPS Error!",scroll_speed=0.02, text_colour=[255,0,0], back_colour=[0,0,0])
		

# import dependencies for Audio Recording
import subprocess
from decimal import *



#import the GPIO functions for RPM sensing
if log_revs == "yes":
	import RPi.GPIO as GPIO
	GPIO.setmode(GPIO.BCM)
	GPIO.setup(18,GPIO.IN) #set up pin 18 for input 
	global last_rpm
	last_rpm = 600 

############################################ Functions ############################################

 
def file_setup(filename): # setup the CSV headers using the right options for any add-ons like GPS
	header  =["runtime",
	"accel_x","accel_y","accel_z",
	"pitch","roll","yaw",
	"mag_x","mag_y","mag_z",
	"gyro_x","gyro_y","gyro_z",
	"temp_h","temp_p","humidity","pressure"]
	
	if log_revs == "yes":
		header +=["rpm"]	
		
	if usb_gps_installed == "yes":
		header += "alt","lat","lon","mps","mph","gpstime"

	with open(filename,"w") as f:
		f.write(",".join(str(value) for value in header)+ "\n")

def get_sense_data(): # Main function to get all the sense data
	global sense_overlay_data  
	global moving
	global launch_time
	global run_time
	sense_data=[]
  	
	log_time = time.time() - start_time

	acc = sense.get_accelerometer_raw()
	x = acc["x"]
	y = acc["y"]
	z = acc["z"]

	o = sense.get_orientation()
	yaw = o["yaw"]
	pitch = o["pitch"]
	roll = o["roll"]

	mag = sense.get_compass_raw()
	mag_x = mag["x"]
	mag_y = mag["y"]
	mag_z = mag["z"]

	gyro = sense.get_gyroscope_raw()
	gyro_x = gyro["x"]
	gyro_y = gyro["y"]
	gyro_z = gyro["z"]
	
	# Magic timer: This starts a timer if the PI sees an accelleration over a value e.g. a launch.
	# print(moving)

	if moving == 1:
		if y > 0.2: # check y accellerometer to see if you are launching 
			launch_time = time.time() # record the launch time
			moving = 0 # set the variable to say you are launched in this logging session
			run_time = 00.00
		else:
			run_time = 00.00  # if not launching you are stationary		
	else:
		run_time = time.time() - launch_time # you must be launched so the timer is now - launch time 
	
	# now write the sense data to the list
	
	sense_data.append(run_time)
	sense_data.extend([x,y,z])
	sense_data.extend([pitch,roll,yaw])
	sense_data.extend([mag_x,mag_y,mag_z])
	sense_data.extend([gyro_x,gyro_y,gyro_z])
	sense_data.append(sense.get_temperature_from_humidity())
	sense_data.append(sense.get_temperature_from_pressure())
	sense_data.append(sense.get_humidity())
	sense_data.append(sense.get_pressure())

	sense_overlay_data ="Time " + '{: <5}'.format(str(round(run_time,2))) + " Acc-G " +'{: <5}'.format(str(round(y,2))) + " Lat-G " + '{: <5}'.format(str(round(x,2)))
 
	# print(sense_overlay_data)  # prints the overlay data on the screen, left to aid debugging if needed

	return sense_data


def get_rpm_data ():
	global rpm_overlay_data
	global rpm_data
	global last_rpm
	GPIO.wait_for_edge(18, GPIO.RISING, timeout = 50)	
	first_pulse = time.time()
	GPIO.wait_for_edge(18, GPIO.RISING, timeout = 50)
	second_pulse = time.time()	
	pulse_gap = second_pulse - first_pulse

	try:
		rpm = 0.5 /pulse_gap
	
	except:
		# see if there is a devide by zero errror and just fudge the RPM
		# this will make RPM = 600.
		rpm = 10
	
	
	rpm_data = int(rpm*60)
	

	if rpm_data > 8000 :
		rpm_data = last_rpm
	last_rpm = rpm_data
	rpm_overlay_data =  " RPM " + '{: <4}'.format(str(rpm_data))

	print (rpm_overlay_data) #for debugging, this prints the RPM data to the screen


	return rpm_data

def get_gps_data (): # function that gets the GPS data
	global gps_overlay_data
	gps_data=[]

	lat = format(agps_thread.data_stream.lat)
	lon = format(agps_thread.data_stream.lon)
	speed = format(agps_thread.data_stream.speed)
	alt = format(agps_thread.data_stream.alt)	
	gpstime = format(agps_thread.data_stream.time)[0:19]
	try:
		mph = float(speed) * 2.23694
		
	except:
		mph=0
	gps_data.extend([alt,lat,lon,speed,mph,gpstime])
	gps_overlay_data =  " MPH " + '{: <3}'.format(str(int(mph))) + " " + gpstime

	print("GPS Data", gps_overlay_data)  #prints the overlay data on the screen, left to aid debugging if need
 
	return gps_data

  
def joystick_push(event): # if stick is pressed toggle logging state by switching "value" 
	global value
	global running
	global hold_wait	
	global start_time
	start_time  = time.time()
	if event.action=='released':
	# time.sleep(0.5) #wait half a second to reduce button bounce
		hold_wait = 1 # Resets the wait counter for hold-to-shutdown	
		value = (1, 0)[value] 
		time.sleep(0.1) #wait half a second to reduce button bounce
              
		if value == 1:
			start_logging() 
		else:
			stop_logging()	
    
	if event.action=='held':
		print("Button is held")
		sense.show_letter("H",text_colour=[0, 0, 0], back_colour=[255,181,7])  # prints H on the matrix to indicate held
		hold_wait +=1
		print(hold_wait)
		if hold_wait == 50:
			shutdown_pi()       
		




def start_logging ():	
	print ("Logging started, press joystick button to stop")
	global filename
	global record_process
	global moving
	moving = 1
	batch_data.clear()
	
	gps_set_time = agps_thread.data_stream.time
	if gps_set_time !="n/a":
		os.system('date -s %s' % gps_set_time)
		print ("System time set to GPS time of ",gps_set_time)
	else:
		print ("Could not set system time from GPS !")

	sense.show_letter("L",text_colour=[0, 0, 0], back_colour=[0,255,0])
	filename =  "/media/usb/race_data_"+time.strftime("%Y%m%d-%H%M%S")+".csv"
	file_setup(filename)
	
	# if the camera is installed and works then start recording if not the say its not installed and carry on
	if pi_camera_installed == "yes":
		camera.start_recording("/media/usb/race_video_"+time.strftime("%Y%m%d-%H%M%S")+".h264")   # starts the camera recording 
		if do_video_preview == "yes":
			camera.start_preview(alpha=200) #shows camea on monior for debugging
	
	try: #try to start recording
		if usb_mic_installed == "yes":	
			arecord_cmd = "arecord -D plughw:1 -f cd /media/usb/race_audio"+time.strftime("%Y%m%d-%H%M%S")+".wav"
			record_process = subprocess.Popen("exec " + arecord_cmd,stdout=subprocess.PIPE, shell=True)
	except:
		sense.show_message("Microphone  Error!",text_colour=[255,0,0], back_colour=[0,0,0])


def log_data ():
	global rpm_data
	sense_output_string = ",".join(str(value) for value in sense_data)
	gps_output_string = ",".join(str(value) for value in gps_data)
	rpm_string = ","  + str(rpm_data) + ","
	output_string = sense_output_string + rpm_string + gps_output_string	
	batch_data.append(output_string)
	print (output_string) #prints the video overlay data to the screen for debug/testing 
  
def video_overlay ():
	try:
		if do_overlay_sensedata == "yes": 
			if do_overlay_gpsdata == "yes":
 				camera.annotate_text = sense_overlay_data+rpm_overlay_data+gps_overlay_data
			else:	
				camera.annotate_text = sense_overlay_data		
		else:
			print("Overlay disabled")
	except:
		print("Overlay error, is camera working?")
 
def stop_logging ():
	print("Logging stopped, still ready") # prints to the main screen
	batch_data.clear() #clear out any values in the list
	sense.show_letter("R",text_colour=[0, 0, 0], back_colour=[255,181,7]) 
	if pi_camera_installed == "yes":
		camera.stop_recording() # stops the camera from recording
		if do_video_preview == "yes":
			camera.stop_preview()

	if usb_mic_installed =="yes":
		record_process.kill()
		  	
	
def shutdown_pi ():
	print ("Shutting down the Pi") # displays this on the main screen
	stop_logging()
	sense.show_message("Shutting down the Pi", scroll_speed=0.02, text_colour=[255,255,255], back_colour=[0,0,0]) # show this text on the matrix
	sense.clear()  # blank the LED matrix
	os.system('shutdown now -h') # call the OS command to shutdown	 		


################################################ Main Program #####################################

print("Press Ctrl-C to quit")
global batch_data
global count

sense = SenseHat()
batch_data= [] # creates an empty list called batch_data 
sense.clear()  # blank the LED matrix  
sense.show_letter("R",text_colour=[0, 0, 0], back_colour=[255,181,7])  # prints R on the matrix to indicate "Ready"

sense.stick.direction_middle = joystick_push  #call the callback (function) joystick_push if pressed at any time including in a loop
 
value = 0 
running = 1
hold_wait = 1

print("Ready, press sensehat jostick to start logging") # prints to the main screen

while running: # Loop around until CRTL-C keyboard interrupt   
 
	# print(".")  prints to the main screen after "Ready" not the postion of the comma
	# print("GPS time is",agps_thread.data_stream.time) #debug line to see if GPS has picked up the time
  
	while value: # When we are logging
		sense.show_letter("L",text_colour=[0, 0, 0], back_colour=[0,255,0])
		sense_data = get_sense_data()
		gps_data = get_gps_data()
		rpm_data = get_rpm_data()
		log_data()
		video_overlay()

		if len(batch_data) >= WRITE_FREQUENCY:
			sense.show_letter("W",text_colour=[0, 0, 0], back_colour=[0,255,0])
			print("Writing to file")
			with open(filename,"a") as f:
				for line in batch_data:
					f.write(line + "\n")
				batch_data = []