William Woodall

SparkFun LCD

20 Apr 2015

I've had this SparkFun LCD break lying around for a long time. I think I ordered it back in 2010 along with my mbed and never took the time to get it working. I was doing some electronics stuff today and I noticed it in my electronics tackle box and I thought I'd give it another go.

First off, this is the board I'm talking about:

https://www.sparkfun.com/products/retired/8600

I was able to pretty quickly find a library called gLCD which let me get it going pretty easily. I did run into trouble compiling it, but it was easy enough to fix up. However, the source was not in any VCS I could find (I downloaded it from http://www.railways-in-miniature.co.uk/gLCD.zip). So I "forked" it into a repository on my GitHub account and pushed the origin code and afterwards my patch which gets it working on Arduino versions >= 1.0:

https://github.com/wjwwood/arduino-glcd

After getting it to compile, I should mention I was compiling the TestPattern example which comes with the library, I reasoned out how to wire it up to my Arduino Mega that I was using. I connected things according to this:

//You can use these variables to set the pin numbers
const char RST = 8;
const char CS = 9;
const char Clk = 13;
const char Dat = 11;

And additionally I connected vin to my 3.3v pin on the arduino and the vbatt to the 5v pin. Then it just worked:

gLCD driving a Test Pattern

So that's neat, but I was doing some more digging around and noticed this thread:

https://forum.sparkfun.com/viewtopic.php?f=15&t=15448

In summary, there is an inductor on the board (it's blue with 221 written on it) which gets really hot:

Small blue inductor

And sure enough I touched my finger to it and it was hot! The conclusion on the forum was that it should be replaced with an inductor which can handle more current (around ~500ma). But another suggestion was to replace one of the resistors with a different value, which some reported helped.

I ran out of time to actually try that, but maybe I'll give it a go next time I pull it out of the box.


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