108 lines
3.0 KiB
Python
108 lines
3.0 KiB
Python
import RPi.GPIO as GPIO
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from datetime import datetime
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class Sensors:
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"""Class for communicate with sensors through MCP3008"""
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def __init__(self, config):
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self.mosi = int(config.get('adc', 'MOSI'))
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self.miso = int(config.get('adc', 'MISO'))
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self.clk = int(config.get('adc', 'CLK'))
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self.cs = int(config.get('adc', 'CS'))
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self.channel = 0
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self.config = config
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GPIO.setup(self.mosi, GPIO.OUT)
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GPIO.setup(self.miso, GPIO.IN)
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GPIO.setup(self.clk, GPIO.OUT)
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GPIO.setup(self.cs, GPIO.OUT)
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# read SPI data from MCP3008(or MCP3204) chip,8 possible adc's (0 thru 7)
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def readadc(self):
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adcnum = self.getChannel()
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if ((adcnum > 7) or (adcnum < 0)):
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return -1
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GPIO.output(self.cs, True)
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GPIO.output(self.clk, False) # start clock low
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GPIO.output(self.cs, False) # bring CS low
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commandout = adcnum
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commandout |= 0x18 # start bit + single-ended bit
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commandout <<= 3 # we only need to send 5 bits here
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for i in range(5):
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if (commandout & 0x80):
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GPIO.output(self.mosi, True)
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else:
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GPIO.output(self.mosi, False)
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commandout <<= 1
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GPIO.output(self.clk, True)
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GPIO.output(self.clk, False)
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adcout = 0
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# read in one empty bit, one null bit and 10 ADC bits
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for i in range(12):
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GPIO.output(self.clk, True)
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GPIO.output(self.clk, False)
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adcout <<= 1
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if (GPIO.input(self.miso)):
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adcout |= 0x1
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GPIO.output(self.cs, True)
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return adcout
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# Convert value to volt
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def convertToVoltage(self, value):
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correction = 1
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if (self.getChannelModel() == "arceli"):
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correction = 2
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return value * (3.3 / 1024) * 5 / correction
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# Convert volt to celcius value
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def convertToCelcius(self, value):
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value /= 2
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return (value * (3300.0/1024.0) - 100.0) / 10.0 - 40.0
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def convertToPrintableValue(self, value):
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if (self.getChannelType() == 'voltage'):
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return self.convertToVoltage(value)
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else:
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return self.convertToCelcius(value)
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def getChannelType(self):
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return self.config.get(
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'sensors',
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'SENSOR_' + str(self.channel) + '_TYPE'
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)
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def getChannelModel(self):
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return self.config.get(
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'sensors',
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'SENSOR_' + str(self.channel) + '_MODEL'
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)
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def getChannel(self):
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return self.channel
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def setChannel(self, channel):
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self.channel = channel
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def getValue(self):
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if (self.channel == 8):
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now = datetime.now()
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return now.strftime("%H:%M")
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else:
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raw_value = self.readadc()
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value = self.convertToPrintableValue(raw_value)
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return f"{value:.02f}"
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def main(self):
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print('MAIN')
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