ESP32-S3 LVDS Portable Monitor

1. Features
2. Introduction
3. Choice of components
4. The schematic

Features

• Recycling the LVDS LCD panel from a scrap laptop

  

• Converting into a portable monitor for dual video sources

  • Source 1: ESP32-S3 with an external graphic controller
  • Source 2: HDMI output from your PC

• A switch onboard to select between source 1/2

• To be portable, that means a battery is required (a candidate is HAC-003 replacement battery of Nintendo Switch due to its popularity and availability from Amazon) - verification pending (we need to make sure its capacity is enough to last at least a Netflix movie like 2.5 hours)

  

• A lithium battery charger onboard with power path management for charge-and-work at the same time

• The charging status and mode of operations to be visible on a thumb-sized IPS OLED display

• Audio codec with speaker driver and headphone amplifier onboard

• UART0 program download port onboard for ESP32-S3

• USB Debug port onboard for ESP32-S3

• JTAG port onboard for ESP32-S3

• MicroSD card for storage of graphic media

• Expansion port for all unused IO pins of ESP32-S3

Introduction

From time to time there are scrap laptops and tablets that you may have few units in the garage or store room with heavy dust on them. They are fully operational although a bit slow or just incompatible with the latest software. One of the most useful spare parts is the LCD panel that is still alive.

This repository shows you how to revitalize a scrap laptop's 11.6" LVDS 18-bit LCD panel, to convert it into a jumbo HMI display of ESP32-S3 plus the bonus feature of being a portable monitor for HDMI video sources.

This is the idea of The ESP32-S3 LVDS Portable Monitor:

Choice of components

The LCD panel of laptops usually have a resolution of 1366*768 or higher with an interface called LVDS. Such resolution requires a larger framebuffer and much faster pixel clock to drive. That is why I need an external graphic controller (RA8889) to generate the pixel clock and sync signals, etc.

• Embedded graphic: ESP32-S3 + RA8889 + THC63LVDM83D with major components illustrated below.

At time of writing I have finished a prototype for this part (schematics link). It is fully working with few patches.

• HDMI to LVDS bridge with three options from my knowledge:

  Solution	Pros	Cons
  LT8619C	Low cost, a direct conversion of HDMI to LVDS means simplicity, QFN package that is more easy for PCB layout	NDA required. Not much technical information. A promising source from GitHub with even the register map available link
  TC358870XBG + SN65DSI83	Big companies, much better documentation, more information on GitHub available	BGA packages of both chips mean higher PCB production cost and layout skill. More expensive. An indirect conversion (HDMI>MIPI>LVDS). Extensive programming and configuration required for both chips
  Realtek RTD2660	Being used in consumer grade LED TVs and monitors in high volume. Much easier to get information from the Internet and GitHub. Low cost (around CNY8 only). Converting from VGA and analog video to LVDS too.	A bigger chip.

  I have chosen LT8619C for its smaller size and simpler PCB layout. Personally I love its package more than RTD2660. TC358870XBG + SN65DSI83 is too complex for this project.

  With an evaluation kit of LT8619C there show some nice results with three LVDS panels in my inventory:

  • Evaluation kit of LT8619C

    

  • 12.1" 1280x800 8-bit LVDS panel

    

  • 6.86" 480x1280 8-bit LVDS panel

    

• LVDS mux chip: TS3DV520 5-Channel differential multiplexer switch for DVI/HDMI applications. This chip is compatible with LVDS as long as the bandwidth and voltage levels work within the operating conditions.

• TFT Panel: AUO 11.6" HD 16:9 Color TFT-LCD B116XW03 V0. It is by no means the only panel to support. There are 1280*800 10.1" 8-bit IPS panels too.

A revised system diagram is shown below:

The schematic

Update pending...