LCDInfo.com

Yes, text works but there is very little place for it with a constantly space font. I'm trying to get Espy Sans to work; I'd love to try the Nokia font but I can't find it anywhere.

OK, I just built the CEX machine provided in the schematics and it worked.

My display is a RNH94254/2 R5A and the leds are at pins 8 and 6 by Cex's numbering and ground is pin 7.

I made a small change because I didn't have the ("high power") LM317, i just had the LM317lz, so i doubled the regulators, used one for the LEDS, and one for the logic. I'm running the logic @ 2.8V and the leds at 3.2V max (using alternate values for the trimpot). As a side effect I can adjust the led brightness and the logic voltage does not change.

Also I didn't find the bat85 diodoes, but I found 2 1n5817 in a old motherboard and used them.

Plugged the display to the PC and it was found at address 70. I couldn't do anything else because I think the EXE in the files at the upload is for a display at address 72. I'm using VB2005 and the code isn't compatible (Damn MS!) so now I'm getting VB6 and will try to change the code.]

It will take 6 hours to get VB6 and I can't wait to see it working

Again Thanks CEX, AJ and Buze

PS CEX, did you really use a 10 uF cap at the reset line? I couldn't see it at the picture you posted and I guess it's a very high value, anyway, I used it like your drawing and it worked

Well...
I just changed the code to the piece mrfusion posted (init string) and it shows garbage...

Now I'm stuck. Power off works, and init does something.

Any help? (I'll try to get the datasheet for my controller)

update:

ok, now it seems to work, but the clock isn't updating, I'll review the code and post the news...

Thanks everybody

Hello,

I did not use the 10uF capacitor. I didn’t install it because I did not have one qhen I built the board and it works, but I didn’t know if it will work with every type of LCD, so I kept it in the schematic. And yes, it is better to have separate supplies, but I wnet “the cheap way” J



Regarding the software, once you get the garbage in the LCD, just send the command for writing and then the data. For R5A I think it has the S-43200A controller, so you have to send: 0x70, 0x8C, data1, data2….



Hope you can build the example soon.

Regards,

Cex.

I have that 10uF on the reset line, and nothing bad happened. I supose it would be a better idea to have it between pin 1 and 2 instead of 2 and 3, maybe that was the original intention ?

That cap is there to assure the display is reset at power on.

It works by charging via R3 when the power is switched. The reset signal is active low, so while the cap is not charged, it sends the reset signal.

With a 10Kohm/10uF pair, it takes a "long" time to charge, usualy there is a nanofarads capacitor to do that work.

You already have a 10uF cap (C2) betwen pin 1 and 2 (Vdd and Vss) at the output of the LM317. This one is used to filter the output of the regulator and could be 1uF according to the LM317 datasheet. In my prototype I also used a 0,1uF cap at the input of the regulator, very close to pin3 and ground to filter high frequency transients at the input.

I guess many of you already know that, but it may be helpfull to somebody...

My display is working but is not updating without p.off and re-init, if anybody know what i could do...
UPDATE: my display wasn't updating bacause I forgot to change the power on sequence on the init

maujabur

Good work, glad you got it working ok in the end.
I tested a 0x70 device but it didnt work first time, i happily got a 0x72 device working so ive stuck with that one for now.
I modified my code to accept a webcam input for moving image test to the lcd but the best i can manage is 2-4fps even bufferin the data into an array it doesnt improve on speed, im doing some testing with a USB interface to improve the speed hopefully

to AJ

I'm working on the code to make it generic for the three devices, but I only have the 0x70 LCD, maybe we could join the programs.

I read that Delphi is quicker than VB, and maybe I will use it. Today my PC is not working, so I post from the Mac. I just uploaded my folder to http://mp3.djset.com.br/t68i/T68LCD_70.zip but it's still messy, because I didn't finish it, but it works for my display. I didn't upload the autodetection part, but I added a window to send hex commands to the LCD.

I don't know yet about the maximum transfer speed of the lcd or the i2c specs, maybe it just don't go faster than 4 fps

Sure thing, I will have to wire up my 0x70 to see if it works ok for me

I heard Delphi is quicker aswell, im not sure how that is as i find the only limit to the screen update is the physical communication i find that waiting for the data to transfer over bit bang is incredibly slow and my code slows right down, as i have it running withing a game loop i can see the fps it runs at.
Im sure it will go faster as on my working T68 it can show animation at 10-15fps or there abouts.

Time will tell once i get it working over USB-I2C at around 12mbps is possible

AJ

How do I scan the Webcam via VB? I got interested.

I still didn't put my PC to work. Have to buy some parts...

found this on the i2c specs:



at this pdf: http://www.nxp.com/acrobat_download/literature/9398/39340011.pdf

But I still don't know what mode the displays are capable

EDIT

Found this on the hd66760 datasheet:


But i'm not sure it means High-speed I2C. In that case, we could send up to 50fps to the display!

hmm thats interesting, i overlooked all those interfaces and just stuck with i2c, maybe it isnt the best solution, 50fps like the poor little lcd could cope

I use the ezvidcap control to load my webcam into a picture box where it is then scaled down to 101x80 then i use the getpixel api to write each pixel value away to a buffer once full i send the contents of the buffer to the LCD it means the image loads a lot quicker to the LCD than if i had the write to lcd code within my scan image routine.

AJ

I think the only interface available to the display is the I2C, it may use the HD66760, but only the I2C pins are available.

I don't expect the display can respond to 50 fps, but if it really uses high speed i2c, it could load each frame to the memory very quick.

I've been thinking about buying a I2C-USB adapter, where did you buy yours?

now about colors: in my uploaded program i tried a linear conversion, but it really gets ugly

Im using a FTDI chip which can be configered for I2C , SPI or Jtag, you communicate to it via DLLs. i havnt managed to port the code to the i2c yet as ive only owned the module for a few weeks and have been busy with other things.

I use the following code to convert to the 8 Bit RGB supported by the LCD
It doesnt use the same pallete but it still looks fine.

For y = 0 To Picture1.ScaleHeight - 1
For x = 0 To Picture1.ScaleWidth - 1

i = GetPixel(Picture1.hdc, x, y)
r = i And 255
G = ((i And &HFF00) / 256&) And 255
b = ((i And &HFF0000) / 65536) And 255
r = Int(r / 32)
G = Int(G / 32)
b = Int(b / 64)
ByteArray(s) = (r * 32) + (G * 4) + b
s = s + 1 ' increment byte array by 1

DoEvents
Next
DoEvents
Next
' s=0 resets array to 0
s = 0

AJ,

Thanks for the tip about the webcam.

My conversion routine is :

ponto = Picture1.Point(i, j)
Bitmap = (((ponto) And 255) \ 32) * 32 + (((ponto \ 256) And 255) \ 32) * 4 + (((ponto \ 65536) And 255) \ 64)

it may be a little faster than yours because i make all the conversion at once, but I want to test the folowing as soon as my PC is ready again:

bitmap = (ponto and &HE0 ) + ((ponto \ &H800) and &H1C ) + ((ponto \ &H400000) and 3 )

rem
rem bitmap = RRRGGGBB
rem ponto = BBxxxxxxGGGxxxxxRRRxxxxx

This way, we make the less steps possible, I guess that using [ x\y ] is faster than using int(x/y).

The divisions shift the bits in the 24 bit color (VB scheme) and the AND operator masks the part that we need.

Note that &h3 + &h1C + &hE0 = &hFF

In my display, all that is yellow gets very orange

Again, thanks for the tips

MJ