Fast Serial LCD Interface

serial lcd

This is a serial interface for any LCD using the incredibly common 44780 controller. There are a couple different serial interfaces like this on the market, but this project aims to be a superior version. It can use 5 – 30V with an included regulator. It has ESD protection. True RS232 levels mean you can use really long cables. Up to 8 buttons are also supported. This would work great with a car computer. All of the software and schematics are provided. Have a look around the madhacker site for a lot of other cool projects.

[thanks Stuart]

13 thoughts on “Fast Serial LCD Interface

  1. i’d like to point out that many of maxim’s 232 interface ICs include 15k esd protection.

    the rest of the circuit doesn’t seem to include esd protection. there should probably be a metal-oxide varistor and transil somewhere north of the 7805, to deal with spikes in automotive environments.

  2. I’m currently working on a serial/parallel VFD (Vacuum Fluorescent Display) project. I picked up a few of these on eBay they are 40×2 VFDs have parallel and serial. VFDs are nice as they generate their own light, unlike LCDs and thus are much brighter. I use serial to drive the vfd… keeping things simple. As for input I use a 16×16 keyboard from Parallax (, costy), a 74C922 16 key to binary encoder (plans on, grabbed at and a 6402 based UART (plans:, hard to find, but I picked up a few free samples on the net). I’m considering replacing the UART with one of these nice little FTDI USB => Serial/|| chips. The electronics works good for the most part. Software wise it’s another story. I haven’t seen a single LCD app for the mac (osx, so posix interface). I decided to write my own, learning C at the same time. But I don’t think I have the agily with C to create such a project. Anyone knows of a simple open source project that could help me start out?

  3. you can dremel out a blank drive bezel and poke the LCD screen through. a 16×2 LCD screen is about $6, and if you’ve got an old parallel cable lying around… Coolness on the cheap.

  4. Just wondering is there any good suggestions for a really cheap 4 line LCD with serial interface??? or even a cheap LCD serial interface controller is fine too (as long it can support up to around 4×20 characters) I actually found a few but they r all kind expensive I hope i can keep it under 40 dollars with LCD and controller or the LCD with serial interface

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