start

calibrate.py

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+#!/usr/bin/python
+''' Raspberry Pi, ADS1115, PH4502C Calibration '''
+import board
+import busio
+import time
+import sys
+
+import adafruit_ads1x15.ads1115 as ADS
+from adafruit_ads1x15.analog_in import AnalogIn
+
+# Setup 
+i2c = busio.I2C(board.SCL, board.SDA)
+ads = ADS.ADS1115(i2c)
+
+def read_voltage(channel):
+    while True:
+        buf = list()
+        
+        for i in range(10): # Take 10 samples
+            buf.append(channel.voltage)
+        buf.sort() # Sort samples and discard highest and lowest
+        buf = buf[2:-2]
+        avg = (sum(map(float,buf))/6) # Get average value from remaining 6
+
+        print(round(avg,2),'V')
+        time.sleep(2)
+
+if __name__ == '__main__':
+    print('\n\n\n')
+    print('---- RPi-ADS115-PH4502 Calibration ----')
+    input('Press Enter once you have grounded the BNC connector...')
+    channel = None
+    while channel not in [0,1,2,3]:
+        try: 
+            channel = int(input('ADS1115 channel 0-3: '))  # ADS.P0, ADS.P1, ADS.P2, ADS.P3
+        except:
+            print('Not a valid option. Try again.')
+    if channel == 0:
+        channel = AnalogIn(ads, ADS.P0)
+    elif channel == 1:
+        channel = AnalogIn(ads, ADS.P1)
+    elif channel == 2:
+        channel = AnalogIn(ads, ADS.P1)
+    elif channel == 3:
+        channel = AnalogIn(ads, ADS.P1)
+    else:
+        sys.exit('Error selecting an ADS1115 pin.')
+    print('Adjust potentiometer nearest to BNC socket to ~2.50V')
+    print('Starting readings. Press CTRL+C to stop...')
+    try:
+        read_voltage(channel)
+    except KeyboardInterrupt:
+        pass