readacs712-30amp.py

#!/usr/bin/env python3
# read ACS712 30 Amp current sensor with a abelectronics ADC Pi board on channel 1 input
# uses quick2wire from http://quick2wire.com/ github: https://github.com/quick2wire/quick2wire-python-api
# Requries Python 3 
# GPIO API depends on Quick2Wire GPIO Admin. To install Quick2Wire GPIO Admin, follow instructions at http://github.com/quick2wire/quick2wire-gpio-admin
# I2C API depends on I2C support in the kernel

import quick2wire.i2c as i2c

import time


adc_address1 = 0x68
adc_channel1 = 0x98

# for version 1 Raspberry PI boards use: 
# with i2c.I2CMaster(0) as bus:
# for version 2 Raspberry PI boards use: 
with i2c.I2CMaster(1) as bus:
	

	def getadcreading(address, channel):
		bus.transaction(i2c.writing_bytes(address, channel))
		time.sleep(0.001)
		h, l, r = bus.transaction(i2c.reading(address,3))[0]
		time.sleep(0.001)
		h, l, r = bus.transaction(i2c.reading(address,3))[0]
		
		t = (h << 8 | l)
		if (t >= 32768):
			t = 65536 -t
		v = (t * 0.000154	)
		if (v < 5.5):
			return v
		return 0.00
		
		
	def calcCurrent(inval):
		return ((inval) - 2.477) / 0.066;
	while True:
		
		print ("Current: %02f" % calcCurrent(getadcreading(adc_address1, adc_channel1)))
		
		
		time.sleep(1)