Newbie needs advice: GD1 15kHz-Output or GD2 without touchsc

[arcadetv]

Hi guys, I entered the Arduino world 2 weeks ago so please excuse me if my questions seem dumb.

I work as a webdeveloper and I'm totally into electronics and golden-age-videogame systems as a hobby. Now I'm building arduino-driven switchbox for 15kHz-RGB-capable consoles.
It all works very well, I'm having a good time with coding, the hardware and pcb-layouting. I'm using a small OLED I2C display for my visual-output, but i'd love a better presentation for the user.
While searching for embedded GPU's for arduino I found the GD2 with its FT800 to be just what I was looking for.
Having no experience with either GD1 or 2 I do have some questions to evaluate my options for my next decision...

Looking at the GD1's specs I think "why is this 32kHz/VGA only... would have been so nice if it would support 15kHz RGB like many videogame systems do."
I was hoping for being able to present my user-menu directly on the TV (European RGB-capable Scart, 50Hz/60Hz hor. refresh doesn't matter)
Is there a way to run the GD1 in 15kHz? (I guess the GD2 would be out of question, would it??)

So, if creating a 15kHz-video-signal is not an option, I will have to include a screen into my project-box...
A touchscreen would be overkill for this, honestly, so does anybody know of a cheap compatible screen (without touch) for the GD2/FT800?

[jamesbowman]

Right, GD1's display rate is fixed.

Regarding cheaper FT800 options, this one is $28:

www.hotmcu.com/5-graphical-lcd-touchscreen-480x272-spi-ft800-p-124.html?cPath=6_16

it should work with the GD2 library, with a couple of simple changes.

I have not looked at these units, so cannot speak to their quality. The specs look reasonable, but they do not have SDcard, accelerometer or audio output.

[arcadetv]

I bought a GD2 at the german shop that you linked to on the main page so I get to play around with it soon.
Also I found the PSP-display board at AtomSoft's site, I guess I'll give it a try.

James, can I do anything to make you look into the GD1's fpga code and make a 15kHz-Version? ^^
No need to change the hardware, only the timing in the verilog code.
This would be like "Uzebox" (http://www.hwhardsoft.de/english/projects/euzebox/) but for Arduino...

Anyways, thanks!

[arcadetv]

I'm still wrapping up my setup...
There are some quirks while my GD2 is connected to my Arduino MEGA2560 due to long jumper-cables.
I also got the screen from HOTMCU that James recommended.
Could you please explain what needs to be changed in order to get this working with the GD2 library?
Thanks!

[arcadetv]

Feb 9, 2015 21:28:06 GMT -8 jamesbowman said:

www.hotmcu.com/5-graphical-lcd-touchscreen-480x272-spi-ft800-p-124.html?cPath=6_16
it should work with the GD2 library, with a couple of simple changes.

What are the simple changes related to?
Wiring or library?

Thanks!

[jamesbowman]

After from making the SPI hookup - if you change this line:

github.com/jamesbowman/gd2-lib/blob/master/GD2.cpp#L8

in the library so that PROTO is 0, and on the next line set STORAGE to 0, then it should work fine with 3rd party FT800 boards like this - apart from not having the SDcard/accelerometer function.

[arcadetv]

It's been a while since I last visited.. I could reaaalllyyy use a helping hand...

I have the HY43B/HY50B here and it works with the arduino-library from ftdi.
I can't get it to work with the gd2-lib I suspect it may be related to wiring...
I've pulled the latest files from github and changed lines 15 and 16:

#define BOARD BOARD_FTDI_80x // board, from above
#define STORAGE 0 // Want SD storage?

My current wiring on the UNO is:
Adapter ↔ Arduino UNO
5V ↔ 5V
GND ↔ GND
SCK ↔ D13
MISO ↔ D12
MOSI ↔ D11
CS ↔ D8
INT ↔ D2
PD ↔ D4 (I've set the pin HIGH in my test-code, since it's buffered via a LS125 on the TFT-Board, on GD2 it's perm. connected to 3.3V)

The wiring that worked for FTDI's library was:
Adapter ↔ Arduino UNO
5V ↔ 5V
GND ↔ GND
SCK ↔ D13
MISO ↔ D12
MOSI ↔ D11
INT ↔ D10
CS ↔ D9
PD ↔ D4


As for curing curiosity.. the screen looks like this from behind:

[diesel]

Try this
void Setup(){
GD.wr(REG_SWIZZLE, 0);

 I am interested to see the screen quality, those are just $35.00 bezel and all.

[arcadetv]

Inverting the order of the RGB-Bits by calling REG_SWIZZLE did not work
Still getting a white screen.
The quality of the screen is very fair, the only thing that could be better is the viewing-angle.

[jamesbowman]

Right if the FTDI library works then the GD2 library should also work.

Double check that the CS signal agrees with the GD2 library:
github.com/jamesbowman/gd2-lib/blob/master/transports/wiring.h#L2

Run "helloworld" as a first test; it does GD.begin(0) to make sure that only FT800 initialization happens.

[lightcalamar]

Hello i have solution for this display, today working on GD2 !!!! ;
www.hotmcu.com/5-graphical-lcd-touchscreen-480x272-spi-ft800-p-124.html?cPath=6_16

This Shieds of hotmcu.com pin PD_N (POR) Power On Reset))  external R+C line this circuit,



Resuts this screen;


withArduino MEGA, ...
More information this link; Arduino FT800CB HY43B/50B
Best regards!

P:S: sorry my bad English, Spanish user.

[jamesbowman]

Nice! Is it possible to connect PD_N to a Arduino digital pin (e.g. pin 6), and then the Arduino can reset it like this:

pinMode(6, OUTPUT);     // pull pin 6 (FT800 PD_N) low
digitalWrite(6, LOW);
delay(5);               // hold low for 5 ms
pinMode(6, INPUT);      // release

GD.begin();


because then there are no extra components?

[lightcalamar]

Thanks James
With you code not work.

After consulting datasheet IC FT800 only POR (Por On Reset (Page 49)) 5ms, else runnig, this working:

#define PDNPin 8

// INTO SETUP
pinMode(PDNPin, OUTPUT);
digitalWrite(PDNPin, HIGH);

delay(20);
digitalWrite(PDNPin, LOW);
delay(20);
digitalWrite(PDNPin, HIGH);
delay(20);


Best regard

[tofumax]

I stil not find e solution for my problem

mega 2560+ Ft811 gon frozen

could you send mi a GD2-3 Library which works witf mega 2560

and arduino softwere you use

[lightcalamar]

Put your library, then put the connection diagram and I can help you
Regards