Let's Make Robots!

The LCD from hell now lives!!

Well folks, it works...

It turns out I was trying to run this LCD from a bad Picaxe chip.

Here is why the chip is bad

Much thanks to rik (and all others) for their help in the diagnosis

I promise to re-write this post and give everyone all the info I have learned through this ordeal, but for now, I am going to go play with my new display!!!!!!

Thanks again, folks -We're a good family here.

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Super-Duper Simple...

The display has 3 screw terminals on the back, + Gnd and Rx (serial in). From output 7 (doesn't matter which output) I ran a 1k resistor, in series, to the serial in to the display. I don't really know if you need the resistor, but it seemed like a good idea to me. I shared + and gnd with the same 4.5v that is going to the picaxe. That's really it. Here is some code...


pause 1000
setfreq m8 'you need to set freq. to 8hz to get a 9600 baud

serout 7,T9600_8,(254, 128)    'Sets line 1 position 1

pause 20
serout 7,T9600_8,("Text here")

pause 20
serout 7,T9600_8,(254, 192)    'Sets line 2 position 1

pause 20
serout 7,T9600_8,("Text here line 2")

pause 500
serout 7,T9600_8,(254, $01) 'Clear Screen

goto main

So just to be clear, all you used was leg 7 out on the PICAXE, 5vdc, gnd, and Rx on the LCD? What display are you using?

Here is what I picked up: http://www.sparkfun.com/commerce/product_info.php?products_id=791

SFs description reads: "You will need ~11 general I/O pins to interface to this LCD screen"

CtC's LCD has this little serial translator on the back, that apparently has a 4 bit interface to it's attached LCD. That covers all but 4 of the pins on the LCD.

So that's what he meant by "3 screw terminals on the back."

 Gotcha. Thanks guys.


Hey Chris,


Does increasing the freq. to 8 hz to get the required baud rate pose a problem to the chip?  I thought these chips like to run at 4 hz?



I dunno -- I switch to 8hz to send to the LCD and switch back to 4hz when I am done. --Going to 8hz can't harm the chip, but you do have to recalculate all your pauses etc...

Yup, it is.

Did you ony use the dispaly or that and something else?

I just went back and checked the link you showed. That link is for the basic model --one that uses parallel communications. The one shown in this post has a "serial backpack". The term used is "Serial Enabled".