18F w/64240A Display

Testing/Troubleshooting
1

Hi…

I’ve started putting the parts for my LC box together - including the Graphics LCD which is the Displaytech 64240A. I followed the hookup diagram in the LCD section of the site and when i apply power to the core it powers up fine and the pots work as expected (lum (pot on core) and con(additional pot wired in)). However, after burning the bootstrapper to the pic, and then mios via syx, I dont get the MIOS welcome msg on the LCD like i’ve done with the character LCD used on the 18F Sid i started. I put the appropriate ID Value in ICProg for the KS controller before burning the bootstrapper (0000000000001000)…

After sending mios and applying power i get:

F0 00 00

F0 7E 40

F0 00 01

F0 F7 00

but it doesnt repeat every 2 secs, so that makes me think that mios sysxed correctly and so should display the MIOS screen…but it aint :confused: it just stays filled black as before…

Have i missed summin?

2

Hi Dan,

important question: did you wire the graphical LCD based on the updated schematic? Because I changed one connection before the final MIOS release.

A simple way to test if the ID has been set correctly is the use of the (undocumented *sigh*) debug message which allows you to call a MIOS function from external.

So, when you send:

F0 00 00 7E 40 00 0D 01 00 5A 44 00 00 00 00 00 00 00 00 F7

the “MIOS_LCD_TypeGet” function will be executed. The return parameters will be sent back by the MIDIbox:

F0 00 00 7E 40 00 0F 00 00 00 00 00 00 00 00 F7

if a character LCD has been initialized

F0 00 00 7E 40 00 0F 00 01 00 01 00 00 00 00 F7

if a graphical LCD has been initialized.

It’s also possible to setup a graphical display after startup by modifiying the init function in lc_init.inc

Just add:

       movlw   0x01
        call    MIOS_LCD_TypeSet

at the beginning

Best Regards, Thorsten.

3

Hi T…

Okay, so i sent that syx cmd and got this feed back:

F0 00 00 7E 40 00 0D 01 00 5A 44 00 00 00 00 00 00 00 00 F7

which means if has selected the graphical LCD, so it all seems good so far…

I originally connected the LCD last week sumtime - did u change the pdf hook diagram in this time? I’ll check the connections with the one on the site now neways to make sure…

Cheers…

Dan

1 Like
4

Meant to paste this:

F0 00 00 7E 40 00 0F 00 01 00 01 00 00 00 00 F7

1 Like
5

okay, the lcd is connected as in the current pdf on the site…

6

Hi Dan,

ok: MIOS is running, it has been configured for a graphical LCD and you see a black screen (means black pixels or just nothing?). So the error must be a missing or bad connection.

Best Regards, Thorsten.

7

Hey T, Yup blackscreen…

I’ve gone over the tracks a few times and they looked good, but it’s happened before and no doubt it’ll happen again - i’ll go through it some more, is there a particular track or connection it could be?

Cheers…

Dan

8

Just to ensure (due to linguistical differences): does it mean that black pixels are visible, or that the screen is blank. :wink:

Best Regards, Thorsten.

9

hehe ;p - yes, the black pixels are visible :wink:

it’s a screen of black pixel blocks…

10

Fine - so it must be a minor problem. :slight_smile:

Power is ok, contrast also. Let’s double check the CS lines, they must be connected to:

CS1 -> Pin RD0

CS2 -> Pin RD3

CS3 -> Pin RC4

CS4 -> Pin RC5

11

arrrgh!!

still no joy, and this is on a new core!

T, can u dble chek the pdf/gif of the connection diagrams as I noticed on there u have:

Pin 16 (CS1) - PIC Pin D2

But u just posted:

CS1 -> Pin RD0

I dunno if it’s just a one-off mistake, as u have the wire going to S0/J8 of the core (which is RD0)…

But just to make sure, can u confirm the rest is def right, as it’s weird i’m gettin the same display (or lack of) with a new shiny core…

Ta

Dan

12

Hi Dan,

so it’s clear - you still have the old schematic. Maybe the file cache of your browser loaded the old plan?

CS1 -> Pin RD0

(J8:SO)

is the correct connection

Best Regards, Thorsten.

13

Hey T…

I just meant in the pic u have:

CS1 -> Pin RD0  

(J8:SO)

but in the text to the right it says:

14

whoops…

…it says:

16 - CS1 (-> PIC PIN D.2)

I had it wired correctly anyways in the first place and still no joy…:frowning:

All connections are fine - hard soldered direct to pin headers…

15

Ok, I see. The text is wrong, but the interconnections are correct.

So - did you try Pin RD0?

Best Regards, Thorsten.

16

yes, 16 was wired to J8/S0 (RD0) all the while…

Best

Dan

17

well i give up - this bastard is killing me!  >:(

I musta retinned and resoldered all connections at least 5 times, i’ve tried using a header on the lcd and soldering to that, wiring direct to the lcd pinouts it’s self - all the same results…:frowning:

18

and now a few solder pads have burnt off with all the soldering/desoldering - great :frowning: there goes my damn LC display…

19

you’ve got mail…

since you plan to send me a T6963C based GLCD for a new MIOS driver, just send me this display too, so that I can search for the problem.

Best Regards, Thorsten.

20

ur a lifesaver T :slight_smile:

I’ll send it all to ya tomorrow…

thanks again…

Dan