Adafruit Sensors

Introduction

In this article,we propose an overview of the Adafruit Circuit Playground Express (CPX) built-in sensors. This aim of this page is to show you how to leverage them in MakeCode. So, if you are not familiar with MakeCode, we advise to have a look on MakeCode page in this wiki.

The CPX built-on sensors available are :

• Buttons
• Capacitive touch
• Light sensor
• Accelerometer
• Microphone
• Switch button
• Thermometer
• Infrared Transceiver.

Coding sensors in MakeCode

In MakeCode, there are two means to read the code : through events or by reading live data:

• Events: code runs when an event is detected. For example, the OnShake event runs code when a certain type of shaking is detected by the accelerometer.
• Live data: live reading of the sensor data without a particular event taking place. For example,Rotation gets a immediate reading from the accelerometer.

You will find below the 2 style of programming with sensors : through events (on left of the picture below) and through live data (on right on the picture below).

Sensors

Buttons

Buttons A & B

On the CPX, there are 2 buttons : Button A or Button B. The two buttons could be coded together Button A + B.

Event

the OnEvent block allows to respond to action (click, long click and other events.

Live data

the button can be read in live by using the input IsPressed that is to say the code check if the button is pressed. You can also used the input WasPressed in situations in which the program have a risk to busy when the user clicked. In this case, the code check if the button was clicked earlier.

Example : The click on button A is used to play a sound. The state of button A is checked in a forever loop to switch between red (if button A is pressed) and green (if nothing happens).

Capacitive touch

Capacitive touch pins

On the CPX, there are 7 capacitive pins (A1, A2, A3, A4, A5, A6 and A7). They can be used as buttons (like buttons A or B).

Event

The pins can be used as touch inputs, the code use them like buttons. Instead of saying Button A or Button B as the input source, use a pin name like A1.

Live data

you can read the live button status using input IsPressed or WasPressed.

Example : An event on pin A4 is used to show pixels animation and the state of pin A7 is checked in a forever loop to switch between blue or red on the neopixels.

Light sensor

Light sensor

Links

At Adafruit

• Sensors in MakeCode

Aknowledgement

Pictures as well as some text was reproduced from the Adafruit circuit playground express documentation. Some pictures are available under a CC BY-NC-SA license. Others are copyright AdaFruit and "all rights reserved" and reproduced with permission. Before you reuse any picture from this website, make sure to look at the license information.

For more information about using Adafruit, see https://learn.adafruit.com.