94 lines
2.7 KiB
Python
94 lines
2.7 KiB
Python
import smbus
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import time
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class Adc:
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def __init__(self):
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# Get I2C bus
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self.bus = smbus.SMBus(1)
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# I2C address of the device
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self.ADDRESS = 0x48
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# PCF8591 Command
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self.PCF8591_CMD = 0x40 # Command
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# ADS7830 Command
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self.ADS7830_CMD = 0x84 # Single-Ended Inputs
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for i in range(3):
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aa = self.bus.read_byte_data(self.ADDRESS, 0xf4)
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if aa < 150:
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self.Index = "PCF8591"
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else:
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self.Index = "ADS7830"
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def analogReadPCF8591(self, chn): # PCF8591 read ADC value,chn:0,1,2,3
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value = [0, 0, 0, 0, 0, 0, 0, 0, 0]
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for i in range(9):
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value[i] = self.bus.read_byte_data(self.ADDRESS, self.PCF8591_CMD + chn)
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value = sorted(value)
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return value[4]
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# TODO: bug in original code???
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#def analogWritePCF8591(self, value): # PCF8591 write DAC value
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# self.bus.write_byte_data(self.ADDRESS, cmd, value)
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def recvPCF8591(self, channel): # PCF8591 write DAC value
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while (1):
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value1 = self.analogReadPCF8591(channel) # read the ADC value of channel 0,1,2,
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value2 = self.analogReadPCF8591(channel)
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if value1 == value2:
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break;
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voltage = value1 / 256.0 * 3.3 # calculate the voltage value
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voltage = round(voltage, 2)
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return voltage
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def recvADS7830(self, channel):
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"""Select the Command data from the given provided value above"""
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COMMAND_SET = self.ADS7830_CMD | ((((channel << 2) | (channel >> 1)) & 0x07) << 4)
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self.bus.write_byte(self.ADDRESS, COMMAND_SET)
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while (1):
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value1 = self.bus.read_byte(self.ADDRESS)
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value2 = self.bus.read_byte(self.ADDRESS)
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if value1 == value2:
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break;
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voltage = value1 / 255.0 * 3.3 # calculate the voltage value
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voltage = round(voltage, 2)
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return voltage
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def recvADC(self, channel):
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if self.Index == "PCF8591":
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data = self.recvPCF8591(channel)
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elif self.Index == "ADS7830":
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data = self.recvADS7830(channel)
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return data
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def i2cClose(self):
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self.bus.close()
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def loop():
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adc = Adc()
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while True:
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Left_IDR = adc.recvADC(0)
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print(Left_IDR)
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Right_IDR = adc.recvADC(1)
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print(Right_IDR)
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Power = adc.recvADC(2) * 3
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print(Power)
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time.sleep(1)
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print('----')
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def destroy():
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pass
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# Main program logic follows:
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if __name__ == '__main__':
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print('Program is starting ... ')
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try:
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loop()
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except KeyboardInterrupt: # When 'Ctrl+C' is pressed, the child program destroy() will be executed.
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destroy()
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