Saturday, April 2, 2011

Project 23 - Basic LCD Control

Apologies for the long delay in posting... I'm currently writing 3 books and all of them seem to have had major chapters due on the same day this past week... and before you say "Are ya crazy?! 3 Books!" - I've got a fourth book that started yesterday and a fifth book looking to start in a month. It's insane. (Fortunately 2 of my current books are looking like they'll finish in the next week or two... but still...)

I've also been working on a "very special project" - Arduino-related, of course - but I can't talk about it just yet... probably will be able to announce something in a week or so, but you'll understand why I've been slow to getting to Project 23.

And I've been looking forward to this project! I have various ideas for Arduino projects of my own, and many of them involve being able to read text on a screen. I read over the code for this project and it makes sense... I really like being able to use an existing library to call on functions rather than code them...

In a previous project, the code was provide for scrolling text on the 8x8 LED display... that's a lot of code to sift through, and I understand it (sort of)... that's what makes this library so useful - rather than have to code the part myself for moving text left to right ... or right to left... the LiquidCrystal library has functions you can call on that take your text and perform these same operations, but you don't have to reinvent the wheel.

One thing you need to know about Project 23 - if you buy a similar 16x2 LCD you'll need to solder some wires onto the open hole leads in order to make it work with your breadboard. I soldered only the wires I needed (to match Figure 8-1) and left the rest open...

That said... I still can't get the project to work! Learning electronics has likely taken at least 1 year off my life expectancy... it can be SO frustrating. I've gotten good at not getting stressed after the first time running a project... over time, I've figured out that 90% of the time it's an error on my part. And it may very well still be an error I'm overlooking, but I just cannot get text to display on the 16x2... it's getting power... the backlight is lit, and I've played with half a dozen resistor configurations trying to find the right contrast... but no luck.

Suggestions are always welcome! Video below showing my circuit and the lack of progress... I'll keep messing with it for a day or two before moving on...


  1. Maybe try using a pot so you can adjust it and see if there is any change.

  2. James,

    Dave (Plastibots) here. I vaguely recall having a similar issue with my beacon LCD from Pulito ( I don't know if this will help, but have posted the BS2 code to the link above if you want to have a look. It's for the Basic Stamp, but converting should be simple.

  3. Dave,

    Thanks for the note... but I finally did get it working.