150 lines
3.3 KiB
Python
150 lines
3.3 KiB
Python
import time
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import atexit
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import board
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import RPi.GPIO as GPIO
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from datetime import datetime
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from adafruit_ht16k33.segments import Seg7x4
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# ADC configuration
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CLK = 11
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MISO = 9
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MOSI = 10
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CS = 8
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CHANNEL = 0 # By default read sensor 0
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# Display configuration
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i2c = board.I2C()
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display = Seg7x4(i2c)
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# Button
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BUTTON = 5 # GPIO5
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# Function called on push button (change sensor)
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def handlePushButton(button):
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global CHANNEL
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CHANNEL += 1
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if ( CHANNEL > 8 ):
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CHANNEL = 0
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display.print(" :"+str(CHANNEL)+"-")
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# On exit
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def handleExit():
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print("GoodBye!")
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display.print("--:--")
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sleep(2)
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display.fill(0)
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# Init program
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def init():
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# Set display
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display.brightness = 1
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display.blink_rate = 0 # Between 0 and 3
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GPIO.setwarnings(False)
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GPIO.setmode(GPIO.BCM)
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GPIO.setup(BUTTON, GPIO.IN, pull_up_down=GPIO.PUD_UP)
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GPIO.setup(MOSI, GPIO.OUT)
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GPIO.setup(MISO, GPIO.IN)
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GPIO.setup(CLK, GPIO.OUT)
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GPIO.setup(CS, GPIO.OUT)
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# Add button event
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GPIO.add_event_detect(BUTTON, GPIO.FALLING, callback=handlePushButton, bouncetime=250)
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pass
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# Convert value to volt
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def convertToVoltage(value):
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return value * ( 3.3 / 1024 ) * 5
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# Convert volt to celcius value
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def convertToCelcius(value):
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return ( ( 3300.0 / 1024.0 ) - 100.0 ) / 10.0 - 40.0
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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(adcnum, clockpin, mosipin, misopin, cspin):
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if ((adcnum > 7) or (adcnum < 0)):
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return -1
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GPIO.output(cspin, True)
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GPIO.output(clockpin, False) # start clock low
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GPIO.output(cspin, 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(mosipin, True)
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else:
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GPIO.output(mosipin, False)
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commandout <<= 1
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GPIO.output(clockpin, True)
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GPIO.output(clockpin, 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(clockpin, True)
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GPIO.output(clockpin, False)
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adcout <<= 1
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if (GPIO.input(misopin)):
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adcout |= 0x1
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GPIO.output(cspin, True)
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#adcout >>= 1 # first bit is 'null' so drop it
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return adcout
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# Main programm
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def main():
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init()
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time.sleep(2)
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print("Let's go!")
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while True:
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if ( CHANNEL == 8 ): # Last sensor => clock mode
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now = datetime.now()
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printableValue = now.strftime("%H:%M")
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else:
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# Get current sensor value
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ad_value = readadc(CHANNEL, CLK, MOSI, MISO, CS)
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value = 0
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# Convert value in readable Volt or Celcius
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if ( CHANNEL == 0 ):
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value = convertToVoltage(ad_value)
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else:
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value = convertToCelcius(ad_value)
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# Format value with 2 decimals
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printableValue = f"{value:.02f}"
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# Clear display
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display.fill(0)
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# Print new value
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display.print(str(printableValue))
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# Wait between next loop
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time.sleep(10)
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atexit.register(handleExit)
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if __name__ =='__main__':
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try:
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main()
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except KeyboardInterrupt:
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pass
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