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Topic: Tablet serial to 128x64 lcd (Read 1 time) previous topic - next topic

luxeomni

Hi i have an old serial tablet ( not a wacom, an easy one to exploit already know what it outputs ), want to to hook it to an arduino then send the data to a graphic lcd. I do a stroke on the tablet and it draws on the lcd. Is it q difficult project ? Can i have some guidance ? Thanks

baum

How large is the tablet? The LCD? It shouldn't be TOO hard, but you may want a multiplexer or a shift register if you run out of pins.

liudr

Depends on your skill level. So your tablet has a 9-pin serial interface?
You may use a max232 chip to convert its 12V signals into 5V TTL for Arduino.
Search max232 chip and download its spec sheet. You will either need some 9-pin connector or cut your tablet connector to hook it to Arduino.

I'd do this:
1) Learn about max232, spec sheet, how to tutorials forum posts
2) Cut the tablet connector or but a mating connector so you can hook it to the max232 chip
3) Feed the 5V side of max232 to your arduino board pins 0 and 1, remove your atmega 328 chip from it.
4) Open the arduino serial dialog and see if the tablet is sending anything that you can read.
5) Use NewSoftSerial (google it) on Arduino board to read positions from tablet
6) Display position on an LCD.

Seem pretty long. Would cost me entire weekend with all parts at hand :)

cyberteque

As the other guys have said get to know how to use your LCD first.
Then look at the output from the tablet by logging the data to a terminal program on your PC.
The tablet output is usually not that complex for a serial one, I managed to write a driver for a big old Wacom for my old Mac Plus in a few hours.

luxeomni

Thanks for all your inputs
The tablet uses 5V, should i still use Max232 chip as suggested ?

baum

There are two types of communication- TTL and RS232. Check out this article:
http://www.sparkfun.com/tutorials/215

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