Need PIC16F84A Cool Project

[Agent 009]

But sometimes, during the flashing, I just c a part flashing...

 

[Jay.slovak]

Maybe your problem lies in the V0 - Contrast pin of the LCD. Make sure to connect it to trimer (VDD and GND) and the LCD to the central tap of it.

 

[Agent 009]

I have already connected the pin 3 (V0) to the central pin of a variable resistor, the other pin of the variable to GND, and the other one to VCC and consequently to pin 2 of the LCD... Isn't that right :?:

 

[Jay.slovak]

I have already connected the pin 3 (V0) to the central pin of a variable resistor, the other pin of the variable to GND, and the other one to VCC and consequently to pin 2 of the LCD... Isn't that right :?:

Yep, and when you turn it, the blocks apppear more or less visible, right?

 

[Agent 009]

Euh, actually, it appear Visible/Not visible... It's very sensitive... But the problem is: I just see a fully fulled screen...

 

[Jay.slovak]

Euh, actually, it appear Visible/Not visible... It's very sensitive... But the problem is: I just see a fully fulled screen...

Is that LCD brand new or is it a used one? Onece I had a problem with used one, it was damaged and didn't work, and it took me a while to figure it out.

 

[Agent 009]

It's brand new!! I bought it 2 days ago :cry: :cry: !!
Jay, could u direct me 2 somewhere where i can actually learn how 2 'speak' with it... I don't want ready-made program: I like 2 create my own... But I need to quite understand how it works...

 

[Agent 009]

By the way, I'm using Nigel's code (Gr8 site Nigel :wink: ), but it's for 628... Did u c it, Jay?

 

[Jay.slovak]

By the way, I'm using Nigel's code (Gr8 site Nigel :wink: ), but it's for 628... Did u c it, Jay?

I wrote my own right from the scrach. Look for Hittachi HD44780 datasheet, it should have enaugh info to make your own program.

 

[Agent 009]

What's with the Hitachi? I'm using a WinStar... They have extremely 'tight' datasheets... Just the pin config and currents and stuff... No further info. I need to know what I do with each pin, not what is each pin...

 

[Jay.slovak]

What's with the Hitachi? I'm using a WinStar... They have extremely 'tight' datasheets... Just the pin config and currents and stuff... No further info. I need to know what I do with each pin, not what is each pin...

That's why we use Hittachi datasheet instead. All 2*16 line LCDs (most of them) are Hittachi compatible.

 

[Nigel Goodwin]

That's very refreshing :shock: ! Hehe, I want now the LCD to work!
But I have the 16F84A... Not the 16F628, which Nigel based his tutorials on... I took out the comparator line, from the code, and changed the porta/trisa to portb/trisb (cause it's 8-bits) and it didn't work :cry: :!: :!: :!:

The LCD code works fine on any 14 bit PIC, it's certainly fine on PortB of a 16F84, or any full port on a 16 series (14 bit) PIC. In fact, it will probably work on almost any PIC, with only very minor changes.

As already suggested, the contrast setting is fairly important, two low and you get nothing, too high and you often get solid black charcaters right across the screen. If ALL you get is solid blocks, it usually shows that the LCD isn't being set up - this is what you get if you don't have the PIC plugged in.

 

[Agent 009]

Yeah... But I think the WinStar is also compatible: they have the same configuration put in Nigel's tutorial...

 

[Agent 009]

Nigel, I'm restarting the connections... I hope this works...

 

[Agent 009]

I didn't work :cry: ...

 

[Agent 009]

I have replaced the Port A connections to Port B connections, Nigel... Do u think it should work, even if it's a 84A???

 

[Nigel Goodwin]

I have replaced the Port A connections to Port B connections, Nigel... Do u think it should work, even if it's a 84A???

Yes, it should work on any full 8 bit port.

 

[Agent 009]

Nigel, I am trying another setup...

 

[Agent 009]

I have received a code, but it isn't workin, too!!! :cry: :!: WHY :?:
I still have these blocks...

 

[Agent 009]

I'm sure it's no resistor-contrast problem, because I am tuning a 'precise' 4k potentiometer... As soon as I get any liquid crystal appearing, I get'em as blocks... It's not that I have 2 much contrast or so...