tianma lcd

Testing/Troubleshooting
1

hi,

I’m having trouble getting the Tianma 2x40 lcd module to work with mb64. Reading the spec. sheet I noticed that it’s controller is a KS0066. I realize now that its the hitachi based modules that work. Is there any hope for these or should I buy another module that is HD based?

Thanks,

Blood    

2

Hi,

KS0066 works w/o problems. I’m also using some LCD modules with this controller.

If you are sure that the PIC is running (does it send some MIDI messages?) then it must be a wiring problem. Last time a friend had a simmilar problem, and the reason was that one of the 16 cables was broken inside the 2-row connector - this problem was very hard to find.. :-/ If we had soldered all cables again, we possibly were able to fix this faster… so my tip: desolder the ribbon cable from the LCD and the core module, maybe check all 16 wires with a multimeter, and solder it again.

Best Regards, Thorsten.

3

yup, its sending midi messages so its probably my wiring.

Its sending lots of midi messages actually over all 16 channels and pretty fast too.

On the wiring is VD (CORE) the same as VCC (LCD)?

Thanks!

Blood

4

> Its sending lots of midi messages actually over all 16 channels and pretty fast too.

This means that you haven’t tied the open (unused) analog inputs to ground…

> On the wiring is VD (CORE) the same as VCC (LCD)?

yes

Best Regards, Thorsten.

5

I’m not really seeing any difference clamping unused inputs to ground. I’m only using 16 pots so I left out 2 4051. Should I clamp all unused inputs from J3 and J4 on AIN to ground or just the outputs from J6 A2 and A3 to ground and is case ground or the ground from j5 gonna work, cuz i tried all of these and still no message on the lcd just a green glow and contrast all the way and down and midi messages a blaze.

also only button 1 from din sends a midi message all others are dead.

6

Of course, as I wrote: all analog inputs.

But you could also reduce the number of pots in main.asm of the MIDIbox64 application - this will save you from soldering.

One 1 button: check the serial connections. Check also the PCBs for short circuits

Did you make the PCBs by yourself?

Best Regards, Thorsten.

7

Thorsten,

I finally grounded the ain inputs to the power supply and BINGO everything works. The DIN had some short circuits from sloppy soldering.  The LCD is still glowing green but no messages :frowning:

Thanks a ton,

Blood