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Nokia 6100 LCD and PIC16F877A

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Vizier87

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Hi everyone,

1. I've setup my Nokia 6100 LCD, read the datasheet and some tutorials by Jim Lynch (Sparkfun) with some improvisations. I built the circuit using just a perfboard, and hopefully got it all right.

The only thing is, the example programs are a bit harder for me to understand, since they use libraries. I only want to test the LCD and see if my setup is working, so I need a code to just light it up. I can, however, write bare C programs without libraries.

So basically, here's how I connected everything:
1. RC5 (SDO) to SDI of the LCD,
2. RC3 (SCK) to SCK of the LCD,
3. RB2 (PORTB) to RESET
4. RB3 (PORTB) to CS

I shifted the voltage output of the PIC using diodes to around 3.9V (The max rating, I believe is 4.0V from what I read in the datasheet)

Also, I used an LM7808 (8V output) to power the lighting.

So, can anyone guide me to a simple, library-free test program? I've fossicked everywhere for it, no avail though.

2. There's also another thing. I tested the output of the PIC's toggling output (to simulate a SCK and SDO signal) at 1ms interval. After the signal goes through two voltage-dropping diodes, the output is like this:

View attachment 60498

I wonder if it affects the performance of the LCD?


Thanks for the time spent on this guys.

Vizier87.
 
Hi Ian,
I've opened the file. It seems that it's written in C18? I can't make it work even after modifying it to my best knowledge. I'm using MikroC, by the way. *aaaaargh*
 
The picture on you scope indicates you don't have much of a pull down on those lines. The PIC pulls up hard. It looks like there is (almost) nothing pulling down. This will limit your speed.
 
Well I think so too.... I compiled it for 877A, and the error mentions of "not able to find includes" this and that. There's a missing link here...

anyway I think I need to understand just in parts... Do I get any output just by sending any random SPI data to the LCD? Just to test if there's random screen appearance.
 
The picture on you scope indicates you don't have much of a pull down on those lines. The PIC pulls up hard. It looks like there is (almost) nothing pulling down. This will limit your speed.

This is the result of using the diodes to clamp the voltage to around 3.9V, though I think I need to add another layer of diodes to bring it to a safer 3.4-3.5V.

What do you suggest then?

Thanks for the replies guys.
 
I wonder why is it that the developers of the library for the LCDs DIDN'T use the SPI feature of their PICs? Why write a long program when you can use the peripherals?

I'm also unsure of whether it's an Epson or Phillips controller...

Some input might help me shed some light on this matter.....

Thanks.
 
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