COG LCD Character Module with SPI Interface

For some applications adding an alphanumeric display, particularly an LCD Character Module could be a plus, not only as a Human Machine Interface (HMI) but also as an output interface for device diagnostics and troubleshooting.

Nowadays Character Module LCDs are quite inexpensive, most of them use a parallel interface based old Hitachi HD44780 or its Samsung cousin KS0066 controllers.

You will also find some folks selling a Character Module LCD with an add-on serial interface or things like the Serial Enabled Backpack from Sparkfun.

On one of my projects I showed how to interface a regular Character Module using the SPI interface taking advantage of the Microchip MCP23S08 port extender.

I’ve been looking around for a while for a reasonable priced integrated solution, preferable with Chip On Glass Technology that does not take to much pcb real state.

To my satisfaction I recently found that the folks from Electronic Assembly in Germany started to produce the DOG-M LCD series that is exactly what I was looking for.

The DOG-M LCD display series, not only provide the classic parallel interface but they also offer using the same controller the SPI interface option, and guess what you can use them with +5V or +3.3V supply.

There are different variants including STN yellow/green, reflective, STN blue, FSTN positive and negative, some of which require a backlight, but EA also offer a nice collection of LED based backlighting with ultra thin construction.

The EA DOG-M display series is available from Mouser Electronics.

I’ll be using the 3 x 16 model for one of the products I’ve under development.

I'll soon post some pictures with the DOG-M displays in action.

Cheers

Jorge

From the 4004 to modern microcontrollers

Since the introduction of the first logic gates ICs and the Intel 4004 and later the Motorola 6800, I’ve been always interested in digital electronics and microprocessors. I had a lot of fun with the legendary 4004 but I really learned a lot about microprocessors when I was able at school to put my hands in one Motorola MEK6800 D2 evaluation kit and later due my involvement with Texas Instruments a TMS9900 evaluation board.
It was an interesting challenge in those days to develop certain applications due the limitations in memory space and processor speed. I learned to program these antiques entering the code directly in a hexadecimal keyboard. I can still today recite parts of the 6800 instruction set.

No doubt that since the introduction of the 4004, microprocessor technology has evolved tremendously and even following Moore’s law I could have never imagined the computing power and features that we can find in today’s microprocessors.

But there was something that caught my interest couple of years ago and in which I’ve been working lately, microcontrollers.

While a microcontroller does not have the same feature set and processing power of modern microprocessors, they are very suitable for a vast number of applications and include many features and peripherals that may have required a large collection of integrated circuits in the past.

And they are everywhere!! If you drive a relative modern car, chances are very high that your car may have a dozen of them, many appliances today replaced electromechanical controls by microcontrollers, your garage door opener use them, and you may even find them in pregnancy test sticks.

I hope through this blog to share some of my experiences dealing with microcontrollers and related devices. Currently many of the projects I’m working on are based on microcontrollers from Microchip Technology, but I’ll include some posts about Atmel, Texas, Freescale and others.

Enjoy !!