Which plugin for x7jay7x's solution?

Iska · Post by **Iska** » October 4th, 2008, 10:50 pm

Hey everybody,

I just finished making the print according to x7jay7x's schematic but... I got nothing on my LCD :S:S, I think I got the wrong Display Plugin (using matrix.dll right now). So does somebody know which one I need to use my LCD?

Thanks in advance,
Iska

Iska · Post by **Iska** » October 4th, 2008, 10:57 pm

I'm using a USB -> Serial converter btw

I think that also the reason why I just got 2 rows of squares (invalid intiliazing)

Post by **caesar** » October 5th, 2008, 8:31 am

if your display has 4 lines then having the first and third filled with black characters is very good, but also means that you've done something wrong. Xjay's backpack should initialize the display right after startup so you should see no black bars.
That backpack works with the matrix driver.

If you have a 2 lines display then it is possible that you connected the contrast pin to the + side of the power source or you have some extended temperature LCD that needs negative voltage for contrast. In these two cases the whole display is filled with black squares.

Triple check the connections and make sure that you've got a HD44780 LCD.
What's the display's datasheet?

Iska · Post by **Iska** » October 5th, 2008, 11:11 am

I got a HD44780 for sure (used it more times) and it's a 20*4 display. I'm going to check the pin's now, hopefully i;ve done something wrong with that...

EDIT: I think I got it, I connected the 10k-resistor to the gnd instead of the +5V, so that means that the PIC is constantly resetting itself

Iska · Post by **Iska** » October 5th, 2008, 12:31 pm

BTW, I haven't used the buttons.. but that doesn't matter i guess

Iska · Post by **Iska** » October 5th, 2008, 1:48 pm

I tested all the wires and all of them turned out to be o.k. :S:S:S But when I tried to read the output from the PIC-pins while he was on, they all appeared to be 0.0V! Does that mean that my PIC is dead??

Post by **caesar** » October 5th, 2008, 10:31 pm

if nothing is sent to the display then reading 0V on the PIC pins is ok.
try with it connected to the computer and LCDSmartie started.

What level shifter are you using? Are you sure you got the RX-TX pins right?
RX on com port is connected trough the level shifter at TX on the PIC
TX on com port is connected trough the level shifter at RX on the PIC

Iska · Post by **Iska** » October 6th, 2008, 7:46 am

X7JAY7X's schematic which wire the Rx and Tx is so I'm not sure :S

Post by **caesar** » October 6th, 2008, 4:51 pm

Still didn't answer what level shifter you use!

COM Tx pin #3------------LEVEL--------- pin #7 -RB1/RX
PORT Rx pin #2 -----------SHIFTER------ pin #8 -RB2/TX

Iska · Post by **Iska** » October 6th, 2008, 5:39 pm

err... I used this schematic for the max232 (http://sodoityourself.com/wp-content/up ... it_232.jpg) and the Rx is connected to RB1 and the Tx to RB2 so I guess I did it right

Post by **caesar** » October 6th, 2008, 9:51 pm

Iska wrote:err... Rx is connected to RB1 and the Tx to RB2 so I guess I did it right

It's exactly the opposite! That's why you don't get it working.

Iska · Post by **Iska** » October 14th, 2008, 5:57 pm

Pin #8 on the uC is constantly +5V.. is that correct?

Post by **mattcro** » October 15th, 2008, 11:49 am

Pin 8 is the transmit from the PIC to the PC, so it will be constantly high (5V) unless the PIC transmits data. That only happens if you press one of the buttons, then the PIC sends a byte of data. You probably can't detect that on a multimeter.

_X7JAY7X_ · Post by **_X7JAY7X_** » November 11th, 2008, 5:26 am

Iska, did you get it working?