Topic: Spi->parallel Lcd (Read 432 times)

greengiant · « **on:** June 17, 2004, 09:01:00 PM »

The SPI2Par adapter is exactly that. It allows you to use a cheap HD44 based LCD (almost all the cheap parallel lcds) on the Xenium with minimal or no soldering
It uses a PIC mcu to convert the signals and allow for plug-play operation.

This means there is NO need to use modified XBMC or any other modifications are needed. The Adapter converts a parallel LCD into a SPI lcd for use on the xenium.
Even includes support for software contrast and backlight (no more pot tweaking)

I will be posting more information on my website as I have it available.

Check it out at http://cheaplpc.com/xenlcd/

It is 3.2cm x 1.7 cm, which means it can hide anywhere. All components are SMT. So it is very thin as well.
Doing this almost at cost, so dont expect anything but the best that my hands can make.
Looking at around $15 and shipping.

Iam taking orders on the 10 prototypes i have to help finance the initial batch. Contact me if you are interested in a prototype.
I will keep this thread and my website updated as I get more ahead.

Jul 9 - Received the first prototype from factory. It looks great.
First picture (IMG:http://cheaplpc.com/xenlcd/proto.jpg)

Jul 12 - Received the SPI connectors today. If you need the connector for your own project or whatever reason, contact me and I would be more than happy to sell you as many as you need.

Dont forget, you can contact me any time via email at [email protected]

This post has been edited by greengiant: Jul 13 2004, 06:45 AM

greengiant · « **Reply #1 on:** June 19, 2004, 01:05:00 AM »

rbn · « **Reply #2 on:** June 19, 2004, 05:56:00 AM »

What other projects have you got going on at the moment?

greengiant · « **Reply #3 on:** June 19, 2004, 09:04:00 AM »

Well I got some revive today.
Finally got the PIC chips programming and the code worked as expected. There is NO synch problems at all with the PIC solution.
As an added bonus to using the PIC, you have some 10-15 extra i/o lines to do with as you please. That means the PIC can be used to also control the LCD baclight, and contrast, as well as control some of the I/O pins for whatever you want. Think of it like the CrystalFonts lcd on steroids.

And its only running at 4mhz.

I will release more info later today.

VERY Excited.

ghostavel · « **Reply #4 on:** June 19, 2004, 09:30:00 AM »

wow i already have an lcd but u have me exited for ur product,nice work can wait to see it .

greengiant · « **Reply #5 on:** June 19, 2004, 11:06:00 AM »

Well I have come to a crossroads in the path of using the PIC. So i want your opinion as to how to procceed.

Two ways to go about it

Have the PIC emulate the commands of the CrystalFontz lcd such that there is minimal changes needed for XBMC, and thus the other apps that already may have LCD support

OR

Go with completely new routines requiring a 'new' LCD if you will in XBMC, just a whole different setting. But this allows the greatest flexibility because its fully customizable and can have what i said earlier about the extra i/o and such.

OR

A variant of both, Have it use the Smartxx method of using the LCD, and only requiring 6 very quick changes to XBMC for it to work. Also the simplest to implement in the code. I may go this route for the public version.

Iam thinking, and trying to see if I can come up with all 3 in 1, using software control.

greengiant · « **Reply #6 on:** June 19, 2004, 01:45:00 PM »

Good to see feedback.

The smartxx way is the easiest, 1 function in xbmc needs to be changed, the display out, and the PIC code is quite simple.

The ones that act as a SPI lcds, are a bit more complicated but its done.
I think it wont be to hard to make it switchable with a dip switch or solder pads. So it should not be any trouble to have all 3 ways.

And if anyone has any ideas or request let me know, lots of room for expansion.

An idea I had, was also to use a charge pump to up the 3.3v to 5v, so you dont have to use any adapters or anything else. Ill see how my charge pump circuit goes, hopefully not too expensvie.

ghostavel · « **Reply #7 on:** June 20, 2004, 07:52:00 PM »

great work green.keeps us updated

greengiant · « **Reply #8 on:** June 20, 2004, 08:46:00 PM »

flabbergast thank you for the offer.

At the moment Iam going to need to have a prototype made of the PCB i posted above. My current manufacturer can make it but there is a delay of about 1-2 weeks, with this prroject iam hoping to make some 5 prototypes and have the pcb made in a week at most. Im willing to pay, hopefully not too much. The cheapest quick prototyping i have found, is about $20/board in 5 days. Please let me know if you can be of assistance.
Or if anyone else.

Thanks.

Ive been thinking, I may end up having a "send me 3 PIC, get the kit free" type of deal. That way you order samples from Microchip (free) send em to me, and I send you a complete kit free. Thats assuming I also get normal orders to offset the cost of the boards and parts, or I may do a "send in 2 PIC's + $2 and get a kit"
Some sort of deal for low cost people. Even though $10-15 is already cheap as it is.

Also,
I have found a source of LCD's. 100 20x4 for $6/each or 100 16x2 for $5/each
I may do complete LCD+Adapter kits, if theres demand for the complete unit.

running_wild · « **Reply #9 on:** June 20, 2004, 08:48:00 PM »

1 question.. If we lack a PIC programmer, can we put it in the xbox and program it via some xbox software once it is all built?

Just a question from a n00b

greengiant · « **Reply #10 on:** June 21, 2004, 10:23:00 AM »

No you wont be able to. It will come pre-programmed (the pic that is).
But I can program the chip for you, if your a do it yourselfer.

greengiant · « **Reply #11 on:** June 21, 2004, 06:55:00 PM »

Yeah, I implemented 2 modes.
1, Smartxx way
2, Crystal Fonts emulation

With the command set used by Crystal Fonts in their LCDs you can set the Contrast and Backlight from commands.
So, the support is there, and the PCB itself has 8 extra i/o for future things. 2 of those is the LCD contrast and LCD backlight.

The backlight off course is made for those LCD's that use an LED backlight that only requires GND and 5V. Those that require a negative voltage or use special lights may not work thru the software control, but with a relay or something of the sort (possibly a transistor) it can at least be on/off from software.

Contrast Iam working on fully implementing it in the code, thinking exactly how to do it via hardware, but I should have it fully done sometime tonight or tommorow.
At the moment it is simply connected via a resistor to GND.

And off course there is the 8 i/o for any future stuff. Mind you the pic does have to be re-programed with the new code for the new features, but that will be available for free.

The PIC is a 16F876A that will be used. Iam not exactly sure how it will go if completely free as I said before "3 for free kit" or if it will be "1/2 + lil $ for kit" but I will have something for those who want as cheap as possible.

The lcds is more of an investment so that I will look after the circuit board is complete.

moobar · « **Reply #12 on:** June 21, 2004, 10:03:00 PM »

Its been a while since Ive worked with these LCD's but heres an idea Id like to bounce off ya if you still have some cycles left over.

You could try to implement a HDD and LAN signal with 2 extra wires tied to vcc and the HDD and LAN idle lines to a couple of inputs.

Use maybe the upper-right 2 characters (0x12 and 0x13) of an 20x? display for example. Maybe use a character with alot of dots so its easy to see, or write a custom one to CGRAM.

Have one dip that the user can either close or open to specify he is using 16x? or a 20x? display so you can get the upper-right position correct.

If the user chooses not to use this feature, no harm, the inputs are tied high.

The input polling cycles wont eat to much but the writing to LCD might.

mlwood37 · « **Reply #13 on:** June 22, 2004, 09:16:00 AM »

.

Thats what you get for being a cheep skate lol.

I would be willing to pay upwards of £15.00 for one in a kit form inculding the wires to mount it at the front of the xbox.

Glad to see such skills in the scene from some very clever PPL. Ill be whaching you space as son as you ready to do either Beta testing or selling the product full ill be there waiting with a cheque.

hopefully you will be able to send these to the UK. hint hint.

greengiant · « **Reply #14 on:** June 22, 2004, 11:35:00 AM »

The HDD/LAN idea is a possibility, the I/O is there, but it may interfere with the software thats using the LCD, so what iam moving to is having all the options programmable via software. A small, simple xbe that sets the settings of the LCD. Ill look more into it.

kingmt, yes thats how it will ship. There will be diff versions, depending on your skills. One will have the Xen connector + wires soldered to the board ready for install.

Its looking at around $15 and $4 for shipping anywhere (worldwide) and handling is included.

Author Topic: Spi->parallel Lcd (Read 432 times)