#!/usr/bin/env python

# Written by Limor "Ladyada" Fried for Adafruit Industries, (c) 2015
# This code is released into the public domain

import time
import os
import RPi.GPIO as GPIO
import sys
import datetime
import time
import csv

from csv import reader

# Setup the RPI pin with BCM labeling
GPIO.setmode(GPIO.BCM)
GPIO.setup(18,GPIO.OUT)

# Power management registers
power_mgmt_1 = 0x6b

# Turn on relay (pin 18), HIGH means "ON"
GPIO.output(18,GPIO.HIGH)
DEBUG = 1

# read SPI data from MCP3008 chip, 8 possible adc's (0 thru 7)
def readadc(adcnum, clockpin, mosipin, misopin, cspin):
        if ((adcnum > 7) or (adcnum < 0)):
                return -1
        GPIO.output(cspin, True)

        GPIO.output(clockpin, False)  # start clock low
        GPIO.output(cspin, False)     # bring CS low

        commandout = adcnum
        commandout |= 0x18  # start bit + single-ended bit
        commandout <<= 3    # we only need to send 5 bits here
        for i in range(5):
                if (commandout & 0x80):
                        GPIO.output(mosipin, True)
                else:
                        GPIO.output(mosipin, False)
                commandout <<= 1
                GPIO.output(clockpin, True)
                GPIO.output(clockpin, False)

        adcout = 0
        # read in one empty bit, one null bit and 10 ADC bits
        for i in range(12):
                GPIO.output(clockpin, True)
                GPIO.output(clockpin, False)
                adcout <<= 1
                if (GPIO.input(misopin)):
                        adcout |= 0x1

        GPIO.output(cspin, True)
        
        adcout >>= 1       # first bit is 'null' so drop it
        return adcout

# change these as desired - they're the pins connected from the
# SPI port on the ADC to the Cobbler
SPICLK = 11
SPIMISO = 9
SPIMOSI = 10
SPICS = 8

# set up the SPI interface pins
GPIO.setup(SPIMOSI, GPIO.OUT)
GPIO.setup(SPIMISO, GPIO.IN)
GPIO.setup(SPICLK, GPIO.OUT)
GPIO.setup(SPICS, GPIO.OUT)

# 10k trim pot connected to adc #0
potentiometer_adc = 0;

last_read = 0       # this keeps track of the last potentiometer value
tolerance = 5       # to keep from being jittery we'll only change
                    # volume when the pot has moved more than 5 'counts'
print('% Voltage')
while True:
        # read the analog pin
        trim_pot = readadc(potentiometer_adc, SPICLK, SPIMOSI, SPIMISO, SPICS)

        print (trim_pot)
        #Write Temp data to csv file
        mydate = datetime.datetime.now()
        with open("/home/pi/Desktop/Currentdata.txt", "a+") as tempFile:
            tempFileWriter = csv.writer(tempFile)
            tempFileWriter.writerow([mydate,trim_pot])

        if  (abs(trim_pot) > 600):
                GPIO.output(18,GPIO.LOW)
                print("Threshold Exceeded!")
                sys.exit()
        #set_volume = abs((trim_pot) / 10.24)  # for potentiometer             
        #set_volume = abs((trim_pot-512) / 10.24)*800 #for mA current sensor # convert 10bit adc0 (0-1024) trim pot read into 0-100 volume level
        #set_volume = round(set_volume)          # round out decimal value
        #set_volume = int(set_volume)            # cast volume as integer

        #print (set_volume)

        #print ('Voltage = {volume}%'.format(volume = set_volume))

        # hang out and do nothing for a half second
        state = GPIO.input(18)
        if  (state is 0):
                sys.exit()
        time.sleep(2)

GPIO.cleanup()