ADCDevice.py

import smbus

class ADCDevice(object):
    def __init__(self):
        self.cmd = 0
        self.address = 0
        self.bus=smbus.SMBus(1)
        # print("ADCDevice init")
        
    def detectI2C(self,addr):
        try:
            self.bus.write_byte(addr,0)
            print("Found device in address 0x%x"%(addr))
            return True
        except:
            print("Not found device in address 0x%x"%(addr))
            return False
            
    def close(self):
        self.bus.close()
        
class PCF8591(ADCDevice):
    def __init__(self):
        super(PCF8591, self).__init__()
        self.cmd = 0x40     # The default command for PCF8591 is 0x40.
        self.address = 0x48 # 0x48 is the default i2c address for PCF8591 Module.
        
    def analogRead(self, chn): # PCF8591 has 4 ADC input pins, chn:0,1,2,3
        value = self.bus.read_byte_data(self.address, self.cmd+chn)
        value = self.bus.read_byte_data(self.address, self.cmd+chn)
        return value
    
    def analogWrite(self,value): # write DAC value
        self.bus.write_byte_data(address,cmd,value)	

class ADS7830(ADCDevice):
    def __init__(self):
        super(ADS7830, self).__init__()
        self.cmd = 0x84
        self.address = 0x4b # 0x4b is the default i2c address for ADS7830 Module.   
        
    def analogRead(self, chn): # ADS7830 has 8 ADC input pins, chn:0,1,2,3,4,5,6,7
        value = self.bus.read_byte_data(self.address, self.cmd|(((chn<<2 | chn>>1)&0x07)<<4))
        return value