Mini LCD Adapter Backpack
Over the past month I have been working on a simple I2C adapter for the common Hitachi LCD displays.
These adapters are already widely available but only for displays with a single row of pins and I had a couple of displays with dual row pins which I wanted to use with a microcontroller.
I started this project a month ago but despite the simplicity of the design it took a while to complete as each revision of the board took 2 weeks to produce and ship from China, this is one of the reasons why I like to run several projects alongside each other.
The board is based around a PCF8574, an 8 bit IO expander, it basically allows the 8 pins required for the screen and backlight to be controlled via a single I2C link. The first board worked perfectly which I was really pleased with but the pin connections didn't match the chinese adapter I was duplicating which resulted in unwanted code changes so a version 2 was needed, I also took the opportunity with version two to add labeling for the main input pins.
I initially set out to make a few of these for myself but I decided to make a few more and to list them on Tindie incase anyone else needed something like this, it was also an interesting experiment in small scale production.
Mini I2C LCD Adapter on Tindie
Like the larger adapters you can get this one is designed to fit perfectly on the back of the screen