CircuitPython on Wio Terminal

CircuitPython is a lightweight programming language based on Python, designed for microcontrollers. The Wio Terminal by Seeed Studio is a versatile embedded device that supports CircuitPython, making it an excellent choice for IoT, ML, and sensor-based applications. This guide provides an in-depth look at installing, configuring, and using CircuitPython on the Wio Terminal.

Wio Terminal is powered by the ATSAMD51P19 microcontroller, a powerful ARM Cortex-M4F chip running at 120MHz, with the following features:

• Memory & Storage:
  • 4MB External Flash
  • 192KB RAM
  • MicroSD card slot for external storage
• Display:
  • 2.4” LCD screen (320×240 resolution, IPS)
• Connectivity:
  • Built-in Wi-Fi and Bluetooth (via Realtek RTL8720DN)
  • USB-C connection
  • UART, SPI, I2C for external communication
• Built-in Sensors & Modules:
  • Accelerometer (LIS3DHTR)
  • Microphone
  • Light sensor
  • Buzzer
  • IR Emitter
  • Real-Time Clock (RTC)
• Expandable Features:
  • Grove connectors for easy sensor and peripheral integration
  • Compatible with Raspberry Pi HATs via a 40-pin GPIO expansion

CircuitPython is an ideal programming language for Wio Terminal due to the following benefits:

• Ease of Use: Simply copy your Python code to the device and run it.
• No Compilation Required: Write code in Python and execute it directly.
• Extensive Library Support: Adafruit’s CircuitPython libraries support a vast range of sensors and peripherals.
• Interactive Development: Supports REPL (Read-Eval-Print Loop) for real-time debugging.
• Low Power Consumption: Optimized for embedded and battery-powered applications.

To install CircuitPython, follow these steps:

1. Visit the CircuitPython downloads page and search for Wio Terminal.
2. Download the latest UF2 firmware for Wio Terminal.

1. Connect Wio Terminal to your computer using a USB-C cable.
2. Enter bootloader mode by holding the BOOT button while pressing RESET once.
3. The device will appear as a USB drive named WIO-BOOT.
4. Drag and drop the UF2 firmware file onto the WIO-BOOT drive.
5. The device will reboot, and a new drive named CIRCUITPY will appear.

Use any text editor, but Mu Editor is recommended:

• Download and install Mu Editor (supports CircuitPython by default).

• Download the Adafruit CircuitPython Bundle from Adafruit.
• Extract the ZIP file and copy necessary libraries into the lib folder on the CIRCUITPY drive.

Create a file named code.py in the CIRCUITPY drive and enter:

import board
import time
import digitalio

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT

while True:
    led.value = not led.value  # Toggle LED
    time.sleep(0.5)

This script blinks the onboard LED every 0.5 seconds.

import board
import displayio
import terminalio
from adafruit_display_text import label
from adafruit_st7789 import ST7789

display = board.DISPLAY

text_area = label.Label(terminalio.FONT, text="Hello, Wio!", color=0xFFFFFF, x=50, y=60)
display.show(text_area)

while True:
    pass  # Keep the display on

import board
import busio
import adafruit_lis3dh

i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_lis3dh.LIS3DH_I2C(i2c)

while True:
    x, y, z = sensor.acceleration
    print(f"X={x}, Y={y}, Z={z}")
    time.sleep(1)

import board
import audiobusio
import array

i2s = audiobusio.I2SIn(board.GP0, board.GP1, board.GP2)

while True:
    data = bytearray(100)
    i2s.readinto(data)
    print("Audio Data:", data)

import board
import pwmio
import time

buzzer = pwmio.PWMOut(board.GP18, duty_cycle=0, frequency=440, variable_frequency=True)

for freq in [440, 880, 1760]:
    buzzer.frequency = freq
    buzzer.duty_cycle = 32768  # 50% duty cycle
    time.sleep(0.5)
    buzzer.duty_cycle = 0

Wio Terminal’s RTL8720DN Wi-Fi module is not natively supported by CircuitPython. Instead, you can:

• Use Arduino firmware to establish Wi-Fi connections.
• Communicate via UART between Arduino firmware and CircuitPython.

CircuitPython on Wio Terminal is a powerful way to develop embedded applications with ease. With its user-friendly interface, wide library support, and real-time debugging capabilities, CircuitPython unlocks endless possibilities for IoT, ML, and automation projects. Whether you’re a beginner or an experienced developer, Wio Terminal with CircuitPython is a game-changer for embedded development.