BS2p24 to CrystalFontz 2X16 LCD display - Hello world Init Sequence

chrisdlove

Dear Parallax Forum,

sharing the code, schematics, and full details to wire and initialize a CrytaFontz 2X16 4-bit parallel bus LCD display to a BS2P24.

https://forum.crystalfontz.com/showthread.php/6229-BasicStamp-and-633?p=30868#post30868[/url]
https://forum.crystalfontz.com/showthread.php/6229-BasicStamp-and-633

https://forum.crystalfontz.com/showthread.php/6229-BasicStamp-and-633?p=30868#post30868

Regards,
Chris.

EGGHEAD

Thanks for sharing Chris.

Publison

Thanks for sharing that!

chrisdlove

Adding a follow-on comment:

I've connected the CrystalFontz LCD panel using a straight ribbon cable - about 10" long. One thing i've noticed is that reloading and running the code 10X in a row sometimes cause only Row 1 to be initialized. The top LCD row will become far darker when this happens. The solution to ensure both rows are active is to repeat the command to initialize two rows with a "PAUSE 500" between them. This seems to reliably result in two rows being initialized.

I suppose there is some debouncing going on on one of the lines....I"ve tried longer pauses but the only reliable solution is to repeat the commend twice. The other possibility is that there is capacitive charging on the line where the TTL value is in the middle ground. I've seen this happen as well with the Parallax outputs lines as well. Which root cause is to blame is unclear without an oscilliscope.

Either way, this is a quick fix and sharing so everyone can benefit!

Regards,
Chris.

Capt. Quirk

Do you have a 4.7k to 10k pull down resistor on the E wire?

Bill M.

chrisdlove

Hi Capt. Quirk,
sorry I did not check back for such a long time. I did not use a pull down on the enable line but likely that will help the situation! I will definitely try it and see if this improves.

Thanks for the advice,
Chris.