adc.py

#!/usr/bin/python3

#imports
import spidev
import time as _time
from array import *
from datetime import datetime, timedelta, time
import RPi.GPIO as GPIO
import atexit


#Define Variables
delay = 0.5
ldr_channel = 0
base = 0
HOST = '127.0.0.1'  # The server's hostname or IP address
PORT = 65000        # The port used by the server

#Create SPI
spi = spidev.SpiDev()
spi.open(0, 0)
spi.max_speed_hz = 1350000 #setting the maximum frequency of the spi

#define input pins for the buttons:
RESET_SWITCH = 11 #button for reset the timer and cleaning the console
FREQUENCY_CHANGE_SWITCH =15 #button to be used to change the frequency of the application
STOP_START_SWITCH = 29 #the button to be used to start and stop the taking of data
DISPLAY_SWITCH = 33 #button to display the results

#variables to be used in the program
frequency = .5
readings_recorded = [None]*5
timer = 0
recording = False
index =0

def exit_handler():
    print("Cleaning up")
    GPIO.cleanup()

atexit.register(exit_handler)

def delay():
    _time.sleep(2)

def freq_change_handler(channel_number):
    global frequency
    print("Change frequency presse")
    if frequency == .5:
        frequency = 1
    elif frequency == 1:
        frequency = 2
    elif frequency == 2:
        frequency = .5
    delay()

def reset_handler(channel_number):
    print("\033[H\033[J")
    print("reset pressed")
    delay()

def start_stop_handler(channel_number):
    global recording
    print("Stop/Start pressed\n")
    recording = True if (recording == False) else False
    delay()

#setting board and gpio pins
GPIO.setmode(GPIO.BOARD)

def readadc(adcnum):
    # read SPI data from the MCP3008, 8 channels in total
    if adcnum > 7 or adcnum < 0:
        return -1
    r = spi.xfer2([1, 8 + adcnum << 4, 0])
    data = ((r[1] & 3) << 8) + r[2]
    return data

def readLdr():
    ldr_reading = readadc(0)
    return ldr_reading

def sendData(time):
	global HOST
	global PORT
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
    s.connect((HOST, PORT))
    s.sendall(str(time).encode)
	
def wavedetected():
    global base
	wave = True
	time_start = time.time()
	while(readLdr()-base>100):
	     if(time.time()- time_start) > 5:
		     wave = False
			 base = readLdr()
			 break
			 
	if(wave):
	    time_end= time.time()
		duration = time_end - time_start)
		print("Wave lasted " +str(duration))
		sendData(duration)
		#send this to the server over a socket 
def main():
    global base
	base=readLdr()
    while True:
        ldr_value = readLdr()
        if(ldr_value - base > 100)
		    wavedetected()

if __name__ == "__main__": main()