Lcd pin out help

[rhino]

4DMC-202-1

Datasheet is from the same place Darrel points to.
http://www.esnips.com/doc/c88ddf19-9...d83cfe251/4dmc

20X2 character display. KS0076B controller.

[Ioannis]

I don't know about G-LCD's but recenty I had an issue with an 2x16 LCD from Winstar.

All known LCD's I 've used up to this moment had the #1 pin as GND and #2 pin as Vdd. The Winstar has the power supply in the opposite order! So read the manuals and Data Sheet is still valid!

Also I used to ground the contrast pin as it was not necessary to adjust it. All LCD that I got this month need to be adjusted through a trimmer! And I did not put that thing on the PCB... :-(

Ioannis

[smeghead]

many thanks again everyone, i have now got the top one connected and it displays 1 row of black squares, i tried the lcd test code but am getting no joy,
so i reprogrammed a simple light an led code which works in the velleman programmer/test board but doesnt seem to work on breadboard, I think this is down to my stupidity,i think the lcd test is written using an external xtal, i've reread the manual but cant seem to work out how to use the internal oscillator on the 16f628a, will have another play when i've calmed down :lol:

Oh and i exploded a pic earlier, got a new power supply from maplins, read the destructions ,dialed in 5v lcd was blank so turned up the current and the voltage dropped to 3v so adjusted the voltage to get 4.5v, then adj the current a bit , the voltage shot up to 25v and bang.

still these thing happen

again many thanks to everyone for replying

[mackrackit]

Do you have a pot/trimmer connected to the contract pin of the LCD?

Oh and i exploded a pic earlier, got a new power supply from maplins, read the destructions ,dialed in 5v lcd was blank so turned up the current and the voltage dropped to 3v so adjusted the voltage to get 4.5v, then adj the current a bit , the voltage shot up to 25v and bang.

I have said it before and I will say it again.
Always have safety glasses on while programming

[smeghead]

nope had the contrast pin to 0v

Do you have a pot/trimmer connected to the contract pin of the LCD?


I have said it before and I will say it again.
Always have safety glasses on while programming

think i will from now on :lol: even the dog jumped

[Ioannis]

So, do you think that using an 7805 is an option? So even if you have a 100Volt/100 Amp Power supply, your PIC circuit will be a bit safer.

Ioannis

[smeghead]

So, do you think that using an 7805 is an option? So even if you have a 100Volt/100 Amp Power supply, your PIC circuit will be a bit safer.

Ioannis

i had one on the board but didnt connect it, simply a case of stupidity on my part :lol: