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adafruit-feather-rp2040

5 min read

Important Note

This entire repo was AI created - including all of the data within. The intent was to A) help me with my personal electronics inventory; and B) see how I could use AI to make that process a bit easier. DO NOT TRUST!

Adafruit Feather RP2040

Details

  • Location: Cabinet-1, Bin 32
  • Category: Feather Boards
  • Type: RP2040 Development Board (Feather Form Factor)
  • Microcontroller: RP2040 (Dual ARM Cortex-M0+ @ 125MHz)
  • Brand: Adafruit
  • Part Number: 4884
  • Quantity: 1
  • Product URL: https://www.adafruit.com/product/4884

Description

A new chip means a new Feather, and the Raspberry Pi RP2040 is no exception. This Feather features the RP2040, and all niceties you know and love about Feather including built-in lipoly charging, tons of GPIO, and the standard Feather form factor that’s compatible with all FeatherWings.

Specifications

  • Microcontroller: RP2040 32-bit Cortex M0+ dual core @ ~125 MHz
  • Logic/Power: 3.3V
  • Memory: 264 KB RAM, 8 MB SPI FLASH, No EEPROM
  • Crystal: 12 MHz for perfect timing
  • GPIO Pins: 21 total (4 ADC, 16 PWM capable)
  • ADC: Four 12-bit ADCs (one more than Pico)
  • Peripherals: Two I2C, Two SPI, Two UART
  • PWM: 16 PWM outputs
  • USB: USB Type C connector with built-in ROM bootloader
  • Regulator: 3.3V with 500mA peak current output
  • Battery: Built-in 200mA+ lipoly charger with status LED

Dimensions

  • Board Size: 51.0mm x 23.0mm x 7.5mm (2.0” x 0.9” x 0.3”)
  • Weight: 5g (light as a large feather!)
  • Form Factor: Standard Feather compatible

Image

Adafruit Feather RP2040

Features

  • Standard Feather form factor compatible with all FeatherWings
  • Built-in 200mA+ lipoly charger with charging status indicator LED
  • Pin #13 red LED for general purpose blinking
  • RGB NeoPixel for full-color indication
  • On-board STEMMA QT connector for easy I2C device connection
  • Both Reset button and Bootloader select button
  • Optional SWD debug port can be soldered in
  • 4 mounting holes for secure installation
  • UF2 bootloader for easy programming
  • Boot button connected to GPIO #4 for user input

Pinout Diagram

Feather RP2040 Pinout

Basic Wiring Examples

Feather Pin D13 → Built-in LED (no external wiring needed)
OR
Feather Pin D5 → LED Anode (long leg)
LED Cathode (short leg) → 220Ω Resistor → Feather GND

Button Input Circuit

Feather 3V → 10kΩ Pull-up Resistor → Feather Pin D4
Feather Pin D4 → Button → Feather GND

Code: digitalRead(D4) returns HIGH when not pressed, LOW when pressed

I2C Device Connection (STEMMA QT - Recommended)

Simply plug STEMMA QT cable between Feather and I2C device
No wiring required! STEMMA QT provides:
- 3.3V Power
- Ground
- SDA (Pin SDA)
- SCL (Pin SCL)

Manual I2C Connection

I2C Device     Feather RP2040
----------     --------------
VCC       →    3V
GND       →    GND
SDA       →    SDA
SCL       →    SCL

Note: Built-in pull-up resistors included

SPI Device Connection

SPI Device     Feather RP2040
----------     --------------
VCC       →    3V
GND       →    GND
SCK       →    SCK
MOSI      →    MO (MOSI)
MISO      →    MI (MISO)
CS        →    Any GPIO pin (e.g., D5)

Analog Sensor Reading

Sensor Output → Feather Pin A0, A1, A2, or A3
Code: analogRead(A0) returns 0-65535 (0-3.3V)

Battery Power

3.7V LiPo Battery → JST PH connector on Feather
Feather automatically manages charging when USB connected
Battery voltage available on BAT pin

Programming Setup Guide

  1. Download CircuitPython UF2 from circuitpython.org
  2. Hold BOOTSEL button while connecting USB-C
  3. Drag UF2 file to RPI-RP2 drive
  4. Board reboots as CIRCUITPY drive
  5. Edit code.py to program

Arduino IDE Setup

  1. Install Arduino IDE 2.0+
  2. Add RP2040 board package URL in preferences
  3. Install “Raspberry Pi Pico/RP2040” boards
  4. Select “Adafruit Feather RP2040” from Tools → Board
  5. Hold BOOTSEL while connecting for first upload

Programming Examples

CircuitPython NeoPixel Example

import board
import neopixel
import time
 
# Initialize NeoPixel
pixel = neopixel.NeoPixel(board.NEOPIXEL, 1)
 
while True:
    pixel[0] = (255, 0, 0)  # Red
    time.sleep(1)
    pixel[0] = (0, 255, 0)  # Green
    time.sleep(1)
    pixel[0] = (0, 0, 255)  # Blue
    time.sleep(1)

Arduino NeoPixel Example

#include <Adafruit_NeoPixel.h>
 
#define NEOPIXEL_PIN PIN_NEOPIXEL
#define NUM_PIXELS 1
 
Adafruit_NeoPixel pixels(NUM_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
 
void setup() {
  pixels.begin();
  pixels.setBrightness(50);
}
 
void loop() {
  pixels.setPixelColor(0, pixels.Color(255, 0, 0));  // Red
  pixels.show();
  delay(1000);
 
  pixels.setPixelColor(0, pixels.Color(0, 255, 0));  // Green
  pixels.show();
  delay(1000);
 
  pixels.setPixelColor(0, pixels.Color(0, 0, 255));  // Blue
  pixels.show();
  delay(1000);
}

CircuitPython Battery Monitor

import board
import analogio
import time
 
# Monitor battery voltage
vbat_voltage = analogio.AnalogIn(board.VOLTAGE_MONITOR)
 
def get_voltage(pin):
    return (pin.value * 3.3) / 65536 * 2  # Voltage divider
 
while True:
    battery_voltage = get_voltage(vbat_voltage)
    print(f"Battery voltage: {battery_voltage:.2f}V")
 
    if battery_voltage < 3.2:
        print("Low battery warning!")
 
    time.sleep(5)

Arduino I2C Scanner

#include <Wire.h>
 
void setup() {
  Wire.begin();
  Serial.begin(9600);
  while (!Serial);
  Serial.println("\nI2C Scanner");
}
 
void loop() {
  byte error, address;
  int nDevices;
 
  Serial.println("Scanning...");
  nDevices = 0;
 
  for(address = 1; address < 127; address++) {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
 
    if (error == 0) {
      Serial.print("I2C device found at address 0x");
      if (address < 16) Serial.print("0");
      Serial.print(address, HEX);
      Serial.println("  !");
      nDevices++;
    }
  }
 
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");
 
  delay(5000);
}

Feather Ecosystem

The Feather RP2040’s standard form factor makes it compatible with the entire Feather ecosystem:

FeatherWings (Add-on Boards)

  • OLED displays (128x32, 128x64)
  • Motor controllers
  • Sensor breakouts
  • Audio amplifiers
  • LoRa radio modules
  • GPS modules
  • And many more!

Stacking and Expansion

  • Stack multiple FeatherWings using stacking headers
  • Breadboard-friendly with standard 0.1” spacing
  • Prototyping area available on many FeatherWings
  • Mix and match functionality as needed

Important Notes

Power Considerations

  • 3.3V Logic: All GPIO pins are 3.3V logic level
  • USB-C Power: Can be powered via USB-C or battery
  • Battery Charging: Built-in 200mA+ LiPo charger
  • Current Limit: 500mA peak from onboard regulator

Pin Limitations and Features

  • ADC Pins: A0, A1, A2, A3 can be used for analog input
  • PWM: 16 pins support PWM output
  • I2C: Two I2C peripherals (I2C0 and I2C1)
  • SPI: Two SPI peripherals (SPI0 and SPI1)
  • UART: Two UART peripherals (UART0 and UART1)

Special Features

  • BOOTSEL Button: Connected to GPIO4 (Rev D+) for user input
  • NeoPixel: Built-in RGB LED for status indication
  • STEMMA QT: Plug-and-play I2C connectivity
  • Battery Monitor: Built-in voltage divider for battery monitoring

Tags

microcontroller, rp2040, feather, stemma-qt, usb-c, adafruit, circuitpython, neopixel, battery-charging

Notes

Perfect for portable projects with the built-in battery charging capability. The Feather form factor makes it compatible with the entire ecosystem of FeatherWings. Supports CircuitPython, MicroPython, and C/C++ development. The 8 consecutive digital GPIO pins provide maximum PIO compatibility for advanced applications.

Graph View

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