From "Spirited Away (2001)" © 2001 Studio Ghibli・NDDTM.

https://user-images.githubusercontent.com/46628917/185350349-dca5a5df-3bee-4c23-829b-23d41562c1f2.mp4

slow-movie-player-7c

Yet another "Slow Movie Player" implementation with 7-color E-Paper module and ESP32.

Features:

• 7-color E-Paper
• microSD (MMC_SD) as the main storage
• Power management by the ESP32 ULP coprocessor
• Battery operated (12 uA @ Deep Sleep. Runs 1.2 years on a 2000 mAh battery.)

Table of Contents

• Background
• Install
• Usage
• Maintainers
• Contributing
• License

Background

A few years later from my previous EPD project SHIHEN, while being impressed on "Slow Movie" and forks ([1], [2]), I was wondering it would be fun if I could also have something bigger and more eye-catching than SHIHEN. One day I found a multi-color E-Paper module available and immediately made an impulse buy. At that time, in Endless Endless Eight I had just started learning how powerful ESP32 ULP co-processor is, especially for battery-powered devices. So I decided to make a yet another variant of slow movie player by combining the two components.

The 7-color EPD module has notoriously long refresh time (>= 30 sec), however by delegating BUSY signal handlings to the ULP co-processor, the ESP32 module itself can be stay in Deep Sleep at most of the time.

Given the ESP32 module in the Deep Sleep mode only draws a dozen uA (Actually 12 uA measured = 6 uA for the module + 6 uA for peripherals.), theoretically the device can survive over a year under a 2000 mAh rated battery and 2 hours of wake interval.

Install

BOM

WIP

• ESP32 (ESP-WROOM-32)
• Waveshare ACeP 7-Color E-Paper Display Module (600x448 5.65inch)
• SMD microSD slot
• microSD card
• M2*5 screws * 4
• AAA batteries * 3

Wire components

See ./kicad.

Print spacers

See ./openscad.

Build firmware

$ pio run || pio run # The very 1st run may fail due to ulptool-pio
$ pio run -t upload

Usage

Prepare video file

Your video file must get converted to a special format before being placed on the microSD. Simply put 1. Dump video frames to a bunch of PNG images. 2. Apply palette to the images. 3. Concat the images into a single file.

You have several options as follows. After obtaining index.bin and images.bin, place them onto the root of your FAT32-formatted microSD.

Option A: With Docker

$ cd converter
$ cp path/to/your_vid_file .
$ docker-compose run --rm converter your_vid_file

Option B: With .sh

• Note that you have to install ffmpeg, ImageMagick, node(v16) beforehand.

$ cd converter
$ ./convert.sh path/to/your_vid_file

Option C: By your hand

1. Dump video frames into .png files.

$ cd converter
$ mkdir -p vid

# -r 1/2 == 0.5 FPS
$ ffmpeg -i path/to/your_vid_file -r 1/2 -vf scale=-1:448,crop=600:448 vid/vid_%06d.png

As you may have noticed, you can use any kind of image sources here not only usual video files.

2. Reduce colors with the following 7-color palette.
   

$ mogrify -monitor -dither FloydSteinberg -remap epaper_7c_palette.png vid/*

3. Generate index.bin and images.bin.

$ npm ci
$ node generate-index-bin.js vid/

How it works

WIP

Maintainers

@likeablob

Contributing

PRs accepted.

Small note: If editing the README, please conform to the standard-readme specification.

License

MIT