Adafruit 4778 2.9 inch Tri-Color eInk / ePaper Display FeatherWing - Red Black White

The Adafruit 4778 is a 2.9-inch tri-color electrophoretic display module that integrates seamlessly with Adafruit Feather microcontroller boards, enabling ultra-low-power IoT and wearable applications with simultaneous red, black, and white pixel rendering. IoT developers, embedded systems engineers, and makers designing battery-powered devices leverage this FeatherWing to create information displays that consume minimal power while maintaining excellent visibility in direct sunlight. This product solves the critical challenge of building long-lasting, always-on displays for remote monitoring systems, smart labels, and portable instrumentation where traditional LCD or OLED screens drain batteries within hours.

Product Overview

The Adafruit 4778 utilizes advanced electrophoretic ink technology where charged pigment particles suspended in a dielectric fluid migrate within micro-capsules in response to applied electric fields. Unlike LCD displays that require constant backlight power, eInk displays only consume energy during image updates, making them ideal for applications requiring weeks of battery life on a single charge. The tri-color variant incorporates red and black pigments alongside white backgrounds, enabling developers to create visually distinctive interfaces with three distinct color states per pixel. The display communicates via SPI interface with configurable clock speeds up to 10 MHz, allowing rapid image refreshes while maintaining low standby power consumption below 1 microamp.

This FeatherWing form factor mounts directly onto compatible Adafruit Feather boards including the SAMD51, nRF52840, and ESP32 variants, eliminating breadboard prototyping and reducing project footprint. The module integrates a dedicated display controller handling all timing and voltage sequencing requirements, simplifying firmware development through Adafruit's well-documented Arduino libraries. Partial refresh capabilities enable updating specific screen regions without full display cycles, further reducing power consumption in applications requiring frequent data updates. The 296 x 128 pixel resolution provides sufficient screen real estate for status indicators, sensor readings, and simple graphical elements while maintaining crisp text rendering at standard viewing distances.

Key Specifications

Specification	Details
Product Type	Tri-Color eInk Display FeatherWing Module
Brand	Adafruit Industries
Origin	Original/Authentic
Warranty	7 days on manufacturing defects
Shipping	1-5 days from Bengaluru
Delivery	7-8 days across India
Support	24/7 via Email and WhatsApp
Display Size	2.9 inches diagonal
Resolution	296 x 128 pixels
Color Capability	Tri-color: Red, Black, White
Interface	SPI (Serial Peripheral Interface)
Operating Voltage	3.3V to 5V
Standby Current	Less than 1 microamp
Refresh Time	1-2 seconds full refresh, 0.5 seconds partial
Viewing Angle	180 degrees

Key Features

• Ultra-Low Power Consumption: Standby current below 1 microamp enables month-long battery operation on coin cell batteries, ideal for remote sensor nodes and asset tracking devices
• Tri-Color Pixel Rendering: Simultaneous red, black, and white pixel states allow creation of attention-grabbing alerts and multi-state status indicators without color dithering complexity
• Direct Sunlight Visibility: High contrast electrophoretic display maintains readability in bright outdoor environments where LCD screens wash out, essential for field monitoring applications
• Partial Refresh Capability: Update only changed screen regions in 0.5 seconds versus 1-2 seconds for full refresh, dramatically reducing power consumption in frequently-updated dashboards
• Feather-Compatible Design: Direct plug-and-play integration with Adafruit Feather ecosystem eliminates soldering and breadboard complexity for rapid prototyping
• SPI Interface with Configurable Clock: Supports clock speeds to 10 MHz for flexible timing optimization between power consumption and refresh speed requirements

Applications and Use Cases

• IoT Environmental Monitoring: Deploy multi-sensor weather stations displaying temperature, humidity, and air quality readings with battery life extending beyond 6 months on AA batteries, eliminating frequent maintenance in remote locations
• Wearable Fitness Trackers: Integrate into smartwatch designs for persistent activity metrics and heart rate data visualization consuming negligible power compared to LCD alternatives, extending wearable runtime to 2-3 weeks per charge
• Smart Shelf Labels: Create dynamic retail pricing displays updating via WiFi or Bluetooth with red highlighting for sale items and black text for regular pricing, powered by small batteries lasting 12+ months without replacement
• Portable Medical Instruments: Build battery-powered diagnostic devices displaying patient vitals and test results with high-contrast readability in clinical environments, maintaining operation for 8+ hours on rechargeable batteries
• Industrial Asset Tracking Tags: Implement location and status displays on equipment using LoRaWAN connectivity with multi-week battery life, eliminating frequent charging infrastructure in warehouse and manufacturing environments
• Educational Electronics Projects: Teach microcontroller programming and display interfacing through hands-on projects with visual feedback, leveraging Adafruit's extensive documentation and community support

How to Use

Begin by installing the Adafruit 4778 FeatherWing onto your compatible Feather board, ensuring all pins align properly with the header sockets. Connect power and ground lines, then install the Adafruit_EPD Arduino library through the Library Manager in the Arduino IDE. Initialize the display object specifying your board's CS, DC, and RST pin assignments, then call the begin() function to configure the SPI interface and perform initial display calibration. The library provides high-level graphics functions including drawPixel(), drawLine(), drawRect(), and drawBitmap() that abstract away the complex electrophoretic timing sequences.

For optimal power efficiency, use partial refresh mode when updating small screen regions by calling the partialUpdate() function instead of the full refresh cycle. Implement image buffering in your microcontroller's RAM to minimize SPI communication overhead, updating the display only when sensor data changes exceed threshold values. Monitor supply voltage during operation as the display controller requires stable 3.3V rails; add 100nF decoupling capacitors near the module if experiencing refresh artifacts. Test your battery life estimates by measuring actual current consumption during various refresh modes using a digital multimeter in series with your power supply, then adjust update frequencies to meet your application's runtime requirements.

Frequently Asked Questions

What is the difference between full refresh and partial refresh modes?

Full refresh cycles clear the entire display by applying specific voltage sequences to all pixels, taking 1-2 seconds but ensuring no ghosting artifacts remain from previous images. Partial refresh updates only changed pixel regions in approximately 0.5 seconds, consuming roughly 25-30% of the energy of full refresh but potentially leaving faint traces of previous content if used excessively. Use partial refresh for frequent small updates like changing a temperature reading, and full refresh every 5-10 partial cycles to maintain image quality.

Can I use this display with non-Feather microcontroller boards?

Yes, the Adafruit 4778 communicates via standard SPI protocol with CS, DC, and RST control lines compatible with any microcontroller featuring SPI hardware or bit-banged GPIO pins. You will need to manually wire the display module to your board's SPI pins and configure the Arduino library with your specific pin assignments. Adafruit provides detailed pinout documentation and example code for various non-Feather platforms including Arduino Uno, Raspberry Pi, and STM32 boards.

How long does the display retain an image after power is removed?

Electrophoretic displays are bistable, meaning pixels retain their charged state indefinitely without power consumption. An image displayed and then power removed will remain visible for months or years until the display is refreshed with new content. This makes eInk displays ideal for ultra-low-power applications like smart shelf labels that update infrequently but must display information persistently.

What is the minimum operating voltage and can I power it from a coin cell battery?

The display operates from 3.3V to 5V, with typical operating current of 50-100mA during refresh cycles and less than 1 microamp during standby. A single CR2032 coin cell provides approximately 220mAh capacity, sufficient to power the display for 2000+ refresh cycles if spaced several minutes apart. For extended operation, use two AA batteries in series (3V) with a low-dropout regulator to maintain stable 3.3V supply voltage.

When will I receive my order?

Orders are dispatched within 1-5 business days from our Bengaluru warehouse. Delivery takes 7-8 days to most locations across India.

What is your return and warranty policy?

We offer a 7-day return policy on manufacturing defects only. Contact support within 7 days of receipt for free replacement or full refund. Not applicable for user damage or misuse.

Are bulk discounts available?

Yes, wholesale pricing for orders of 10 or more units. Contact our sales team via WhatsApp or email for a customized bulk quote.

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Buy Adafruit 4778 2.9 inch Tri-Color eInk / ePaper Display FeatherWing - Red Black White Online in India

Purchase the Adafruit 4778 2.9 inch Tri-Color eInk / ePaper Display FeatherWing - Red Black White online at The Engineer Store, India's trusted source for genuine electronics. We deliver across Bengaluru, Mumbai, Delhi, Chennai, Hyderabad, Pune,