| name | epd-integration |
| description | Use when integrating, porting, or debugging e-paper EPD displays, waveform initialization, SPI drivers, busy pins, partial refresh, ghosting, or low-power display updates |
EPD Integration
Overview
Use this skill to integrate e-paper displays by proving power sequencing, reset, SPI commands, busy timing, framebuffer layout, waveform/LUT setup, and refresh mode. EPD failures are timing and panel-variant sensitive, so driver code must match the exact module.
When To Use
Use this skill when:
- The user wants to add or debug e-paper/e-ink display panels on MCUs or embedded Linux.
- The issue involves blank screen, stuck busy pin, mirrored image, ghosting, partial refresh artifacts, slow refresh, or high sleep current.
- The project uses SPI, GPIO reset/DC/CS/busy pins, external boost power, partial update, deep sleep, or multiple color planes.
Do not use this skill for generic GUI widget logic. Use lvgl-integration or u8g2-integration after the panel refresh path is proven.
First Questions
Ask for:
- Exact panel/module part number, resolution, color planes, controller IC, and vendor demo code.
- Pin mapping for SPI, CS, DC, reset, busy, panel power, and optional enable pins.
- SPI mode/speed, reset timing, init commands, LUT/waveform source, and refresh mode.
- Framebuffer format, bit order, rotation, and partial update area.
- Current symptom, busy pin behavior, and photos if visual output is wrong.
Integration Checklist
-
Match the exact panel.
Resolution, controller, LUT, color planes, and command set must match the purchased module.
-
Prove power and reset timing.
Check panel power, reset pulse, busy pin level, and required delays before SPI commands.
-
Send a minimal pattern.
Render full white, full black, and checkerboard before fonts or images.
-
Validate framebuffer layout.
Confirm bit order, row stride, rotation, black/red planes, and RAM window commands.
-
Add refresh policy.
Separate full refresh, partial refresh, deep sleep, and wake-up flows.
-
Measure low-power behavior.
Confirm panel sleep command, rail shutdown, and MCU pin states after update.
Common Failures
- Driver targets a similar-looking panel with different controller or LUT.
- Busy pin polarity is wrong or not waited long enough.
- SPI DC/CS timing is violated during command/data transitions.
- Image is mirrored because bit order or RAM direction is wrong.
- Partial refresh causes ghosting because periodic full refresh is missing.
- Deep sleep requires a full reinitialization before the next update.
Verification
Before claiming EPD works:
- State exact panel, controller, resolution, color planes, and refresh mode.
- Confirm solid black, solid white, and checkerboard output.
- Confirm busy timing and full refresh completion.
- Confirm partial refresh limitations and deep-sleep current if relevant.
Example
User:
墨水屏偶尔 busy 一直不释放。
Agent:
- Checks panel part number, busy polarity, reset timing, and power rails.
- Compares init sequence with the vendor demo for the exact controller.
- Tests full-refresh-only path before enabling partial refresh or sleep.
