Guide Make your own USB LCD controller!

The new LCD arrived so i decided to add a new pic. All good but hopefully i can get a rotary encoder soon .



Next to start thinking about some sort of mounting for the LCD.

Also the next driver board i make will be about 5mm wider so it can be mounted on the back of the lcd board.

Anyway all i can say is so far this works great, i can highly recomemend this board to anyone who wants a USB interface instead of the standard serial one.

Great work

Scorpia

 

Nice picture, looks like you hve it all up and runing now (other then the encoder). I plan on building a nice small conpact smt version when I get my basement done one of these days.

 

this might be off topic a bit, but it is an lcd. My friend gave me an LCD from his car(he totaled it). Its a 7in. LCD from a in car dvd player. The flipdown ones. I was wondering if there is a way to wire it up to my computer?

 

You should have started a new target here:
LCD FAQ's
or here: Electronics

 

ch424, nice work!

I'm thinking of building one controler but I have some questions about the circuit:

1. The buzzer is connected to RA0. The shematic of other 4 GPOs shows that they're connceted to RA2 - RA5. What is the purpose of RA1? Can it be used for 6th GPO?

2. I can't find any rotory encoder at the local shop. Can I use 3 buttons or keyboard instead?

EDIT: After long searching, I found thisroary encoder. Will it work with this circuit?

 

Update.

i have made a pasic mount and got it all hooked up.



Also i used a different rotary encoder and it works fine with the seperate button. just need to be sure what connections are the button etc.

Overall nice project and works well. Thanks CH424

Scorpia

 

Scorpia: nice!

alig: RA1 is unused currently.... Adobe reader kept on crashing on that pdf, so I'll have a look later.


ch424

 

Source Code?

Hi ch424!
Thanks for the great project!!! Im assuming that you use the "CDC" method of interface with the PC (where you emulate a virtual Serial Port)...

I would like to change this and make it work as a HID Device with the 18F4550, custom software and a few extras such as relay outputs, extra buttons and Infra-Red Receiving for a Remote Control...

Could you please post the C18 (if you use Microchip's C18 Compiler) source code for the LCD part (or the whole code)? The HD44780 datasheet seems quite complex and I would really appreciate a bit of help; esp. on the way to read the busy flag of the LCD and the timing when initializing the Display...

Thanks a lot!
Rene

 

Awesome. I'm just about to build one of these (need to stripboard it cos I got no PCB gear), so a couple of questions:-

1) Has anybody knocked this up on stripboard who would care to share a layout?

2) Do you have the exact part number of the Alps rotary encoder, because there are hundreds of them, all 11mm, all ALPS, on the RS website

Cheers

Hellraiser.............>

 

iiibadboyiii I've sent you an email. No reply yet...

Hellraiser: I don't think there is one, but it shouldn't be too hard... Do post a diagram once you're done!
ALPS rotary encoder - RS Part No. 263-2930 - £4.70
Same as SteveyG's

ch424

 

Cheers mate, putting the order list together now - got my 18f2550's, LCD and mount, pity I'm working Sunday or I could get it all done then

Will let you know how it goes and provide a stripboard layout for those of you (like me) without PCB facilities.

Cheers

Hellraiser............>

 

Hey guys,

just a quick note to let you know that after playing witht e controller a bit i have decided that the rotary encoder i got doesnt work very well .

It seems like the system sees it twice when i turn the knob.

I would be interested to hear how others go with different encoders.

After CH424 posted the part number of the encoder he used i have ordered 2 of these and change to it once it arrives from the UK.

Scorpia

 

Hi Again

I got the PIC18F2550 and I built the JDM programmer from Olimex on breadboard. Then I programmed the microcontroler with WinPic software and I built your circuit on breadboard, but when I connected it to the PC nothing happened.
Then I notised about the configuration bits (this is my first PIC project) but I didn't understand how to enter them in WinPic. Then I searched for another programm which supports PIC18F2550 and found WinPic800. I configured them this way (please tell me if it's right) and I programmed the PIC. Windows recodnised it as CDC RS-232 Emulation Demo. Then I connect this LCD with controller SED1278 which is compatible with HD44780 (till then it was working properly on LPT port) and I notised that it doesn't work how it hve to work. Sometimes the characters aren't diplayed properly and some are missing. The update speed is too low for winamp analyzer and the backlight is blinking when the screens changes or when runnig full screen analyzer. I haven't tested the GPOs yet.
I connected this rotary encoder - ED1112S (the only one I could find) (To open the datasheet you need to install chinese fonts for acrobat or Foxit PDF Reader). When I turn it left or right, Smartie recodnises that I have turned it twice. Could you fix this in the PIC firmware or post here the source code and I'll try to change it
How have to be the settings in Device Manager? Should I left them in default or change them this way ?
Is there something that I'm doing wrong because I really want to make it working.

Anyway, Thanks for the great project and I'll be happy if you help me how to fix it

 

Oh dear, sorry to hear about the trouble with the rotary encoder... the three I've tried worked fine.

alig, I'm working with someone to make a hex file to include all the configuration bits, although I can't see anything wrong with yours. Have you tried downloading the HEX file from the internet again? It might be corrupted. Sounds like a problem with the oscillator or the oscillator configuration.

ch424

 

Hi there, sorry if i seem....stupid or what not, but, is it possible using your method/system to use a full colour lcd, like those found on a ps1 screen etc, and have it display full graphics and pictures. Basicly, im going to be building an Intel based PC, with Intel based colours, and i wanted to have an Intel animation soon after i power on the computer, then for it to tell me that windows is booting, and when windows is running, for it to give me system information. Is this possible? Thanks

Sam

 

To ensure you've not made an error with the programming, do the following:-


Download and install Winpic from:

http://people.freenet.de/dl4yhf/winpic/winpicpr.zip

Download MPLAB 7.42 from:

http://ww1.microchip.com/downloads/en/DeviceDoc/MP742.zip

Unzip and install to default directory (c:\program files\microchip\....)

Run Winpic, go to "Options" tab and point the "MPLAB DEV file directory" to the devices folder in your MPLAB directory.

Close Winpic, re-open - select PIC type (18f2550) and load .hex - voila, under the "Config memory" tab will be all the options you require, set them the same as the config options published at the start of this thread and you're away!


Hellraiser.............>

 

Thanks alot Hellraiser, don't really know what's what in terms of PIC programmers... my school has the official IDC2 kit, so everything's easy...

ch424

 

Couple of things,

1, if the PC see's the unit as a CDC RS-232... then chances are the pic would be programed correctly.

you say your loosing characters etc and getting funny results on the LCD. MY first question would be how long are the cables from the board to the LCD. if they are to long you might have the same problem i was having.

when i changed LCD's from the test 16x2 to the 20x4 screen i shortened the cables and it fixed all the character issues i was having.

AS for the rotary encoder , i am having the same issue , ie turn it one click and it sees it as 2. I have managed to order the same one as Ch424. so i will see how that goes.

Also Ch424 if your redoing the HEX, take the time to modify the USB variable names in both the source code and the driver file. works good for making it your own.

Scorpia

 

I reprogrammed the PIC with WinPic as HellraiserUK said, but the problems remained...

Here are some pictures of the board and LCD



Scorpia, the cable to the LCD isn't very long and I don't think it causes the problem

Tomorrow I'll make a PCB because I think the breadboard is making problems with the connections

 

looks like the cables are about 15cm's. My first one was about 20cm but it wasnt using ribbon cable.

If you still have troubles after you make the PCB then i would try and shorten them anyway.

otherwise it would be interesting to see if the board you have is causing the issues. I hope not as it would be a nice easy way for alot of people to make it.

Good luck.

Also my next idea is to make it into the faceplate of a 5 1/4in drive bay, i have an LCD display 16x2 that will fit so i can make it 100% internal to the case.

Scorpia