How to Use Adafruit Circuit Playground Express: Examples, Pinouts, and Specs

The Adafruit Circuit Playground Express (CPX) is a compact, all-in-one electronic development board that is ideal for beginners and experts alike. It is designed to provide a hands-on introduction to electronics and programming. With built-in sensors, LEDs, and buttons, the CPX is versatile enough to be used in a wide range of projects, from simple educational exercises to complex prototypes.

• Educational purposes (learning programming and electronics)
• Prototyping IoT devices
• Creating interactive wearables
• Developing simple games and animations
• Building assistive technology devices

• Microcontroller: ATSAMD21G18 ARM Cortex-M0
• Operating Voltage: 3.3V
• Input Voltage (recommended): 4.5V to 5.5V
• Digital I/O Pins: 7
• PWM Channels: 7
• Analog Input Channels: 7
• Flash Memory: 256KB
• SRAM: 32KB
• LEDs: 10x mini NeoPixels, each capable of displaying 16 million colors
• Sensors:
  • Temperature sensor
  • Light sensor
  • Sound sensor (microphone)
  • 3-axis accelerometer (motion sensor)
  • Capacitive touch sensor

1. Powering the CPX: Connect the CPX to a computer or battery pack via the micro-USB port.
2. Programming: Use the Microsoft MakeCode editor, CircuitPython, or the Arduino IDE to program the CPX.
3. Connecting Additional Components: Use the alligator clip pads around the edge of the CPX to connect additional sensors, actuators, or components.

• Always ensure that the power supply voltage is within the recommended range.
• When connecting external components, make sure they are compatible with the CPX's operating voltage.
• Avoid static discharge by grounding yourself before handling the CPX.
• When using the NeoPixels, be mindful of their power consumption, especially when displaying bright or white colors.

#include <Adafruit_CircuitPlayground.h>

void setup() {
  // Initialize the Circuit Playground board
  CircuitPlayground.begin();
}

void loop() {
  // Turn on the first NeoPixel with red color
  CircuitPlayground.setPixelColor(0, 255, 0, 0); // Red color
  delay(500); // Wait for half a second

  // Turn off the first NeoPixel
  CircuitPlayground.setPixelColor(0, 0, 0, 0); // No color (off)
  delay(500); // Wait for half a second
}

• CPX Not Recognized by Computer: Ensure the micro-USB cable is properly connected and that it is a data cable, not just a charging cable.
• Unable to Upload Code: Check that the correct board and port are selected in your IDE. Also, ensure the CPX is in bootloader mode if necessary.
• NeoPixels Not Lighting Up: Verify that the NeoPixel code is correct and that the CPX is adequately powered.

• If the CPX is not detected, try using a different USB port or cable.
• Press the reset button twice quickly to enter bootloader mode if you have trouble uploading code.
• When working with NeoPixels, start with lower brightness to reduce power consumption.

Q: Can I use the CPX with a battery? A: Yes, the CPX can be powered with an external battery pack.

Q: Is the CPX compatible with Arduino IDE? A: Yes, with the addition of the Adafruit Board Manager URL, you can program the CPX using Arduino IDE.

Q: How do I reset the CPX? A: Press the reset button on the board. If you need to enter the bootloader mode, press it twice quickly.

Q: Can I connect other I2C or SPI devices to the CPX? A: Yes, the CPX supports I2C and SPI communication, allowing you to connect a wide range of additional sensors and components.