How to Use Adafruit Feather RP2040 ThinkInk: Examples, Pinouts, and Specs

The Adafruit Feather RP2040 ThinkInk (Manufacturer Part ID: 5727) is a compact microcontroller board powered by the Raspberry Pi RP2040 chip. It is specifically designed for low-power applications and features an integrated ThinkInk ePaper display for clear, low-energy visual output. This board is part of Adafruit's Feather ecosystem, making it compatible with a wide range of FeatherWing add-ons.

The ThinkInk display is ideal for applications requiring persistent, low-power visual feedback, such as eBook readers, dashboards, or IoT devices. With its dual-core ARM Cortex-M0+ processor, ample GPIO pins, and built-in USB-C connectivity, the Feather RP2040 ThinkInk is a versatile choice for both hobbyists and professionals.

• Low-power IoT devices with visual feedback
• ePaper-based dashboards and displays
• Portable data loggers
• Wearable electronics
• Educational projects and prototyping

1. Powering the Board:

   • Connect a USB-C cable to power the board via USB.
   • Alternatively, connect a 3.7V LiPo battery to the BAT pin for portable applications.
   • Ensure the EN pin is connected to enable power to the board.

2. Connecting Peripherals:

   • Use the GPIO pins for connecting sensors, actuators, or other peripherals.
   • The board supports I2C, SPI, and UART communication protocols for interfacing with external devices.

3. Programming the Board:

   • The Feather RP2040 ThinkInk can be programmed using CircuitPython, MicroPython, or C/C++ via the Arduino IDE.
   • To upload code, connect the board to your computer via USB-C and follow the programming instructions for your chosen environment.

4. Using the ThinkInk Display:

   • The integrated ePaper display can be controlled using Adafruit's Adafruit_EPD library.
   • The display supports three colors (black, white, and red) and is ideal for static or low-refresh-rate content.

• Low Power Mode: Use the RP2040's sleep modes to minimize power consumption in battery-powered applications.
• Display Refresh: Avoid frequent updates to the ePaper display, as it is optimized for static content and has a limited refresh rate.
• Voltage Levels: Ensure all connected peripherals operate at 3.3V logic levels to avoid damaging the board.
• Battery Safety: Use only compatible 3.7V LiPo batteries and avoid overcharging or deep discharging.

Below is an example of how to display text on the ThinkInk ePaper display using the Arduino IDE:

#include <Adafruit_GFX.h>       // Core graphics library
#include <Adafruit_EPD.h>       // Adafruit ePaper display library

// Define display pins
#define EPD_CS    10  // Chip select
#define EPD_DC    9   // Data/command
#define SRAM_CS   6   // SRAM chip select
#define EPD_RESET 5   // Reset pin
#define EPD_BUSY  7   // Busy pin

// Initialize the display
Adafruit_IL0373 display(250, 122, EPD_DC, EPD_RESET, EPD_CS, SRAM_CS, EPD_BUSY);

void setup() {
  // Initialize serial communication
  Serial.begin(115200);
  Serial.println("Initializing ThinkInk display...");

  // Initialize the display
  display.begin();
  display.setRotation(1);  // Set display orientation
  display.fillScreen(EPD_WHITE);  // Clear the screen
  display.setTextColor(EPD_BLACK);  // Set text color
  display.setCursor(10, 10);  // Set text position
  display.setTextSize(2);  // Set text size
  display.print("Hello, ThinkInk!");  // Display text
  display.display();  // Refresh the display
}

void loop() {
  // Nothing to do here
}

1. The board is not recognized by the computer:

   • Ensure the USB-C cable is data-capable (not just for charging).
   • Double-tap the reset button to enter bootloader mode and reprogram the board.

2. The ThinkInk display does not update:

   • Verify the display connections and ensure the correct pins are defined in your code.
   • Check that the Adafruit_EPD library is installed and up to date.

3. The board is not powering on:

   • Confirm that the EN pin is connected and not pulled low.
   • Check the battery voltage if using a LiPo battery.

4. The display refresh is slow:

   • ePaper displays are inherently slower than LCDs or OLEDs. Optimize your code to minimize unnecessary refreshes.

• Can I use the board without a battery?
  Yes, the board can be powered directly via USB-C without a battery.

• What is the lifespan of the ThinkInk display?
  The display is rated for thousands of refresh cycles, making it suitable for most low-power applications.

• Is the board compatible with FeatherWings?
  Yes, the Feather RP2040 ThinkInk is fully compatible with Adafruit FeatherWing add-ons.

This concludes the documentation for the Adafruit Feather RP2040 ThinkInk. For additional support, visit the Adafruit Learning System.