Create local_altitude.py

examples/local_altitude.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+import time
+
+try:
+    from smbus2 import SMBus
+except ImportError:
+    from smbus import SMBus
+from bme280 import BME280
+
+print("""local_altitude.py - 
+Allows you to correct the QNH for your local area.
+Do not rely on this approximation for landing planes.
+Press Ctrl+C to exit!
+""")
+
+# Initialise the BME280
+bus = SMBus(1)
+bme280 = BME280(i2c_dev=bus)
+
+# asks the user for their local QNH value and confirms it
+local_qnh = input("""Please enter your local QNH value. 
+You can find this by searching for a local METAR on the internet.
+>""")
+print("You have told us the QNH is", local_qnh)
+
+# converts the input into a floating point number
+local_qnh = float(local_qnh)
+time.sleep(1)
+
+# workaround to get rid of the first reading
+altitude = bme280.get_altitude()
+print("Waiting a couple of seconds for the sensor to initialise..."
+time.sleep(2)
+
+while True:
+    altitude = bme280.get_altitude(qnh=local_qnh)
+    print(round(altitude), "metres above sea level")
+    time.sleep(2)