12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

LCD, TFT, OLED, LED modules
alf_sito
Posts: 7
Joined: Thu Dec 12, 2013 7:11 am

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by alf_sito » Thu Dec 12, 2013 1:42 pm

Hi, thanks for your prompt response. It was what I imagined ... This afternoon proceed to remove the R9 and test its proper functioning. When checked it will perform.
Thank you.

alf_sito
Posts: 7
Joined: Thu Dec 12, 2013 7:11 am

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by alf_sito » Thu Dec 12, 2013 6:07 pm

All is OK.
Gracias.

andrew
Site Admin
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Joined: Sun Aug 05, 2012 4:15 pm

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by andrew » Thu Dec 12, 2013 7:10 pm

Glad you got it working. We will update the first post in this thread accordingly.
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addthebadd
Posts: 2
Joined: Thu Jan 30, 2014 10:01 am

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by addthebadd » Thu Jan 30, 2014 10:11 am

Hello, I have just tried to get the example above working to test the screen and although the backlight lights up there is nothing on the display. I have checked the PSD line and it does not appear to have the 0 ohm resistor, and when connected to GND it shows 0v. I am using a Leonardo board rather than an Uno! I have also downloaded the 1.12 version of the library from the link above. I initially tried it with the 1.14 version from the u8glib website but when it did not work I removed the library and installed the version from your site. Any help would be greatly appreciated.

Adam Walker

addthebadd
Posts: 2
Joined: Thu Jan 30, 2014 10:01 am

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by addthebadd » Thu Jan 30, 2014 10:49 am

Hello, I found this...

To get a ST7920 display working all you need is 2 pins.
#define lcdCs U8G_PIN_NONE
#define lcdSck 4
#define lcdMosi 3
#define lcdRst U8G_PIN_NONE
#include <U8glib.h>
U8GLIB_ST7920_128X64_4X u8g(lcdSck, lcdMosi, lcdCs, lcdRst);
After that, PSB to ground, RS to Vcc, Vcc to +5V, Vss to ground, and you're all set.
For backlighting, BLK to ground and BLA gets a 390 ohm to Vcc (or PWM).

And I now have the screen working. Not quite sure what was wrong before, so It would be good if you could shed any light on it.

Thanks, Adam Walker

andrew
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Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by andrew » Thu Jan 30, 2014 11:09 am

This is because the example sketch was written for an Uno (the most common of the Arduino boards). On a Leonardo the SPI interface is assigned to different pins. In the ug8lib library, when creating an instance of it, if no SPI pins are specified it assumes that you are using an Uno and assigns the SPI interface to the default D11 and D13.
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madgadget
Posts: 1
Joined: Wed Feb 12, 2014 7:52 pm

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by madgadget » Sat Feb 15, 2014 9:05 pm

Hi I'm new to this site and just would like to point out that on the 12864ZW model R9 is actually a 27Kohm resistor and not a 0ohm jumper. To put it into serial mode you don't have to remove it like on the 12864B model, you can just connect pin PSB to ground and it will work in serial mode :)

mggrosseto
Posts: 2
Joined: Sat Apr 26, 2014 2:48 pm

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by mggrosseto » Sat Apr 26, 2014 3:04 pm

Hi, I've just ordered this module to be used with a PIC32. I have a question: does it work with 3,3 volt logic or I have to use a level translator?
Any help will be appreciated.
Marco Guerrini

andrew
Site Admin
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Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by andrew » Sun Apr 27, 2014 12:21 pm

Hi I'm new to this site and just would like to point out that on the 12864ZW model R9 is actually a 27Kohm resistor and not a 0ohm jumper.
The manufacture of these screens likes to keep us guessing with the PSB pin. We have seen 3 variations of the design, 2 of which do not need any component changes. However we believe that the current shipped version does not need any modification.
Hi, I've just ordered this module to be used with a PIC32. I have a question: does it work with 3,3 volt logic or I have to use a level translator?
Any help will be appreciated.
According to the datasheet when powering the module at 5V the minimum logic high voltage is 3.5V (0.7 x Vcc). The chipset can be run at 3.3V (allowing it to interface with 3.3V logic) but the contrast for these screens has been fixed to the ideal setting for 5V operation. As a result I think the contrast will be too low to be usable. However if you can drop the supply voltage to the screen to about 4.7V then it may work ok assuming that the DIO on your pic is 5V tolerant. Otherwise you will need a level shifter.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

mggrosseto
Posts: 2
Joined: Sat Apr 26, 2014 2:48 pm

Re: 12864B Parallel/Serial Graphic LCD Module (HCMODU0032)

Post by mggrosseto » Mon May 26, 2014 5:59 pm

Hi, I've been successful in using this module with a PIC32 in parallel 4 bits mode. The pic port is configured in open-drain mode so you just need a pull-up resistor (10k) to 5v on each pin instead of a level converter. Of course you have to use 5v tolerant pins.
Marco

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