Here is the CircuitPython code to turn the Circuit Playground into an inclinometer. Save it to a file named main.py and place it on your Circuit Playground.

CircuitPython only works on the Circuit Playground Express.
# Circuit Playground Express How Tall Is It
# 
# Uses the accelerometer to turn the Circuit Playground into an inclinometer.
# Can be used to determine the height of objects using a little right angle
# math.
#
# Author: Carter Nelson
# MIT License (https://opensource.org/licenses/MIT)
import time
import math
from adafruit_circuitplayground.express import cpx

# Indicate ready using NeoPixel 9.
# Set it red to indicate no good reading yet.
cpx.pixels[9] = ((255, 0, 0))

while True:
    if (cpx.button_a or cpx.button_b):
        # Compute average
        X = 0
        Y = 0
        Z = 0
        for count in range(10):
            x,y,z = cpx.acceleration
            X = X + x
            Y = Y + y
            Z = Z + z
            time.sleep(0.01)
        X = X / 10
        Y = Y / 10
        Z = Z / 10
        
        # Compute angle
        angle = math.atan2(-X, Y)
        
        # Compute total acceleration
        total_accel = math.sqrt(X*X + Y*Y + Z*Z)
        
        # Initially assume the reading is good
        good_reading = True
        
        # Check for levelness
        # Ideally Z=0, but allow a small amount of Z
        if abs(Z) > 1.0:
            good_reading = False
            
        # Check for motion
        # Gravity (9.8 m/s^2) should be the only acceleration, but allow a small amount of motion.
        if total_accel > 10:
            good_reading = False
            
        # Indicate if reading was good
        if good_reading:
            # Green light
            cpx.pixels[9] = (0, 255, 0)
        else:
            # Red light
            cpx.pixels[9] = (255, 0, 0)
        
        # Indicate sign of angle
        if angle < 0:
            # Blue light
            cpx.pixels[8] = (0, 0, 255)
        else:
            # Off
            cpx.pixels[8] = (0, 0, 0)
            
        # Display angle magnitude, in degrees, on NeoPixels 0-7 as 8 bit value.
        # 1 = NeoPixel ON, 0 = NeoPixel OFF
        angle_display = int(abs(angle * 57.29578))
        for p in range(8):
            if angle_display & 0x01 == 1:
                # Turn on the NeoPixel
                cpx.pixels[p] = (255, 255, 255)
            else :
                # Turn off the NeoPixel
                cpx.pixels[p] = (0, 0, 0)
            angle_display = angle_display >> 1

This guide was first published on Oct 25, 2016. It was last updated on Oct 25, 2016.

This page (CircuitPython) was last updated on Nov 17, 2017.

Text editor powered by tinymce.