Display, mainboard, battery, enclosure, buttons, and magnetic back form a complete device.
ZECTRIX NOTE SERIES / 02
NOTE4C
A fully assembled starting point for four-color e-paper
The display, mainboard, battery, enclosure, and mechanical structure are already assembled. Black, white, red, and yellow make it a strong base for labels, status boards, photo cards, and low-power information displays.
Please note: NOTE4C does not include NOTE4's finished consumer firmware or its official AI experience.
NOTE4C / FOUR-COLOR E-INKDISPLAY4.2-inch black, white, red, and yellow display
FORMDisplay, battery, and enclosure assembled
COREESP32-S3 N16R8
OPEN SOURCEFully open reference code
ASSEMBLED HARDWARE
Skip the bare board.
Start developing.
NOTE4C keeps NOTE4's processor, battery, enclosure, interfaces, and mechanical design, replacing the display module with four-color e-paper.
Reference firmware covers Wi-Fi provisioning, image upload and transfer, and four-color display validation.
Spend your time on firmware, data sources, content logic, and peripherals instead of rebuilding the enclosure.
A four-color display on a proven hardware platform.
Designed for individuals and teams with ESP32 experience who want to validate a four-color e-paper product concept.
WHAT TO BUILD
Four colors work best
when updates are occasional
Red and yellow are ideal for emphasizing status, categories, and alerts. Think of it as a low-power static information terminal, not a conventional display that responds every second.
Four-color electronic labels
Use red and yellow to emphasize status, categories, and alerts, giving static labels clearer hierarchy.
Family photos and memory cards
Generate a daily photo, anniversary card, or family reminder from a NAS, album, or other data source.
Desktop AI status board
Display token usage, API calls, cost trends, and service status.
Low-power information display
Show class schedules, calendars, inventory status, room signs, or duty rosters.
Image transfer experiments
Validate image processing, color mapping, transfer workflows, and four-color output.
GPIO peripheral exploration
Connect sensors, buttons, and your own hardware logic to a complete assembled device.
FOUR COLORS, CLEAR SIGNALS
Use color to create a clear information hierarchy
Black and white carry the main content, while red and yellow signal status and emphasis. These examples show possible directions. Actual results depend on your firmware, data sources, and image pipeline.
STATUS BOARD
Desktop AI and service status
Arrange token usage, APIs, cost trends, and service alerts in a static interface that does not need second-by-second updates.
SERVICE STATUS09:30
API USAGE82%
TOKEN BUDGET56%
NAS BACKUPOK
COLOR LABEL
Electronic labels and alerts
Use red and yellow to emphasize categories, priorities, and exceptions.
MEMORY CARD
Photos and memory cards
Update once a day or once an hour to keep family photos and dates visible.
FROM THE NOTE COMMUNITY
A proven form,
ready for new ideas
These comments come from ZECTRIX NOTE series customers and describe the shared physical design and open direction. They are not reviews of NOTE4C itself.
“A great design, useful as it is and equally suited to custom development.”
“The open API makes it easy to connect with my own agent and other services.”
“The build is refined, it looks great, and the magnet is strong.”
For NOTE4C display refresh behavior and software scope, refer to the product details on this page. This section will be updated as direct NOTE4C feedback becomes available.
KNOW BEFORE YOU BUILD
Four-color e-paper
is not a real-time display
Its strengths are low power, image retention without power, and static color. The tradeoff is a longer full-screen refresh, with visible flashing and color inversion during refresh as part of normal operation.
10s+A full-screen refresh typically takes more than ten seconds
GOOD FOR: Static labelsGOOD FOR: Occasional statusNOT FOR: Animation or videoNOT FOR: Second-by-second interaction
It is not recommended for live scrolling, frequently refreshed lists, handwriting tracking, or game controls.
OPEN SOURCE BOUNDARY
Reference code gets you started.
The rest is yours to define.
The accompanying reference firmware is open source and covers Wi-Fi provisioning, image upload and transfer, and basic four-color display validation. It is a working development pipeline, not a complete no-code consumer app.
IncludedProvisioning, image transfer, four-color display validation, and an ESP32 development base
Not includedNOTE4 consumer firmware, official AI voice tasks, or integrations for every third-party data source
REFERENCE FIRMWARE / START HERE
01 connect_wifi(); 02 receive_image(); 03 map_to_4color(); 04 refresh_epd(); // BLACK / WHITE / RED / YELLOW // ESP32-S3 · 400 × 300 // BUILD THE REST YOUR WAY
WHAT IS ASSEMBLED
A complete device,
ready for development
You do not need to assemble the display, power system, flex cables, and enclosure from scratch. Hardware details may vary slightly by production batch.
4.2-inch four-color display, ESP32-S3-N16R8 mainboard, and expansion GPIO.
2,000+ mAh battery, USB Type-C, speaker, microphone, NFC, and status light.
Front and rear enclosure, physical buttons, and magnetic back are fully assembled.
HARDWARE SPECIFICATIONS
Clear hardware and open source boundaries
NOTE4C is built for developers, so its display capabilities, hardware specifications, and firmware scope are stated plainly.
Display
- Panel
- 4.2-inch E Ink display
- Colors
- Black, white, red, and yellow
- Resolution
- 400 × 300 pixels
- Refresh
- A full-screen image typically takes more than 10 seconds
Core
- Processor
- ESP32-S3, dual-core Xtensa LX7
- Memory
- 16 MB Flash + 8MB PSRAM
- Wireless
- 2.4 GHz Wi-Fi + BLE 5.0
Hardware and enclosure
- Battery
- 2,000+ mAh
- Port
- USB Type-C charging and data
- Peripherals
- Speaker, microphone, NFC, status light, and expansion GPIO
- Dimensions
- 97 mm × 97 mm × 8.75 mm, including magnetic back
Firmware and code
- Consumer firmware
- Does not include NOTE4's official consumer firmware
- Reference firmware
- Includes provisioning, image transfer, and basic four-color display validation
- Code
- All accompanying reference code is open source
- Documentation
- Development resources and Wiki documentation are available online
Product form
- Device
- Fully assembled, open four-color e-paper development device
FAQ
Common Questions
Can NOTE4C use NOTE4's AI features?
No. NOTE4C is a development platform and does not include NOTE4's official consumer firmware or AI voice task experience.
Do I need to assemble the hardware?
No bare-board assembly is required. The display, mainboard, battery, enclosure, and core structure are already assembled, but you must develop the software or flash the reference firmware.
Is the code open source?
Yes. The accompanying reference firmware is open source and covers Wi-Fi provisioning, image transfer, and basic four-color display validation.
Why does a refresh take more than ten seconds?
The four-color pigments are driven in multiple stages to clear ghosting and produce the final image. A full refresh is much slower than partial refresh on a black-and-white display, which is an inherent characteristic of the panel.
Is it suitable for a live dashboard?
It works well for status panels that update occasionally, but not for second-by-second refresh, animation, or continuously scrolling dashboards.
BUILD YOUR FOUR-COLOR IDEA
Start your project
with complete hardware
NOTE4C is a fully assembled open four-color e-paper development device for people with ESP32 and firmware experience.