sharks/ride_height.py at master · donour/sharks · GitHub

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#!/usr/bin/python

import quick2wire.i2c as i2c

bus = i2c.I2CMaster()
adc_address1 = 0x68
adc_address2 = 0x69

varDivisior = 16 # from pdf sheet on adc addresses and config
varMultiplier = (2.4705882/varDivisior)/1000

def changechannel(address, adcConfig):
    bus.transaction(i2c.writing_bytes(address, adcConfig))

def getadcreading(address):
    h, m, l ,s = bus.transaction(i2c.reading(address,4))[0]
    t = h << 8 | m
    # check if positive or negative number and invert if needed
    if (h > 128):
        t = ~(0x020000 - t)
    return t * varMultiplier

def setadc(addr):
    mode = 1
    sr = 2   # 0:240, 1:60, 2:15, 3:3.75
    gain = 0 # gain = 2^x

    config_register = 0;
    config_register |= 0    << 5
    config_register |= mode << 4
    config_register |= sr   << 2
    config_register |= gain
    bus.transaction(i2c.writing_bytes(addr, config_register))

start = 0.0
setadc(adc_address1)
changechannel(adc_address2, 0x9C)

def height():
    return getadcreading(adc_address1)

if __name__ == "__main__":
    import sys,time
    while True:
        s = "\r%.6f" % height()
        sys.stdout.write(s)
        time.sleep(0.1)