#!/usr/bin/python

# HM8012 log test
# for a list of available commands, see here:
# https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_manuals/gb_1/h/hm8012_1/HM8012_Digit_Multimeter_UserManual_de_en_03.pdf
# interactive test: sudo minicom -D /dev/serial0 -b 4800

import serial
import time
import datetime
import sys
import Adafruit_GPIO as GPIO

pinA0 = 23
pinA1 = 24
pinA2 = 25

gpio = GPIO.get_platform_gpio()
gpio.setup(pinA0, GPIO.OUT)
gpio.setup(pinA1, GPIO.OUT)
gpio.setup(pinA2, GPIO.OUT)

gpio.output(pinA0, 0)
gpio.output(pinA1, 0)
gpio.output(pinA2, 0)

# open serial port
ser = serial.Serial(
		port='/dev/serial0',
		baudrate = 4800,
		parity=serial.PARITY_NONE,
		stopbits=serial.STOPBITS_ONE,
		bytesize=serial.EIGHTBITS,
		timeout=1
)
print("Port " + ser.portstr + " opened : " + str(ser.isOpen()))

def command(cmd):
  ser.write(cmd + '\r')
  time.sleep(1)
  bytesToRead = ser.inWaiting()
  result = ser.read(bytesToRead)
  withoutControlCharacters = filter(lambda x: ord(x)>=32, result)
  return withoutControlCharacters
  
# test device identification
identification = command('I?')
print('identification: ' + identification)
if 'HM8012' not in identification:
  print('no HM8012 device found')
  ser.close()
  sys.exit(1)

# write log file, measure every 10 seconds
LogDir = '/pub/logs/'
LogFile= LogDir + 'HM8012_Log.csv'

starttime = time.time() - 9
with open(LogFile, 'w') as MeterLog:
  MeterLog.write('TimeStamp,Battery,Peak\n')
while True:
  time.sleep(10.0 - ((time.time() - starttime) % 10.0))
  t = time.time()
  # file is closed while waiting, so that it can be loaded from the webserver
  with open(LogFile, 'a') as MeterLog:
    delta = seconds=t - starttime
    m, s = divmod(seconds, 60)
    h, m = divmod(m, 60)
    timestamp = "%d:%02d:%02d" % (h, m, s)
    time.sleep(2)
    battery = command("S?").split()[0]
    gpio.output(pinA0, 1)
    time.sleep(2)
    peak = command("S?").split()[0]
    gpio.output(pinA0, 0)
    line = timestamp + ',' + battery + "," + peak
    MeterLog.write(line + '\n')
    print(line)

ser.close()