Jummbled text with 16F648 and CFAH1602A


New member
Hello all,
After several problems, I finally have gotten my lcd and Pic to talk and display something. I have a program that just writes text to the screen with 500 and 1000ms delays between each line of text. However when it runs I only get part of the text, and mostly just jumbled characters. Most of the text i have in the program doesnt display at all, and when it does, it is in the wrong row and has all sorts of weird characters mixed in with it. I did have a 6 inch cable going from the pic to the lcd. I thought maybe since each pin on the pic only puts out 25mA, I would try making the cable only an inch or two. After doing that, what was displayed on the lcd was a little more accurate, But im still getting garbage. Right now, I have the whole circuit on a bread board with a 4mhz crystal, would it work better after soldering it together on a perf board?

Any ideas would be greatly appreciated!

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CF Tech

Try adding a delay between when you change the data lines awhen you change E.

Also look for bouncing on E.

The breadboard setup might have grounding issues between the PIC fround and the dispaly ground.