Multiple LCDs

[Geerinckx]

Hi All

After reading reading reading I've started a new midiBox project.

I already own a midiBox128 and a midiBox64 project for controlling lighting software.

But now I've started a LPC17 project to replace the old 1 with 8+ LCD's.

Everything is running, code for Din & Dout is ready.

For now I'm testing with 1 LCD but the plan is to have 8 or more LCD running under Mios32.

I can't find where i can modify the lcd_device_set code

I would like to have it like this:

LCD_1 E-pin ---> I take from J15A

LCD_2 E-pin ---> I take from J15B

LCD_3 E-pin ---> I would like to have on J10.D0

LCD_4 E-pin ---> I would like to have on J10.D1

and so on....

Where do i modify this? I should think in Mios32_Board? But I can't find it.

Can someone point me in de right direction?

Ps Big thx again to TK and his team for this wonderful new project.

Greetings

Gert

[TK.]

Hi Gert,

I will update the "universal" lcd driver under modules/app_lcd/universal soon to simplify such changes, currently they are not obvious (basically you would have to change each line where MIOS32_BOARD_J15_E_Set() is called, it makes sense to add an additional SW layer to overwrite the default function)

Best Regards, Thorsten.

[Geerinckx]

Ah,

Okeey TK, for now i wil just put all J10 outputs in open drain mode, and use external pull-up to 5v.

I think all E lines are anabled at start up, so all displays wil get the same correct initialisation. Correct?

and after init, i just set/reset the correct J10 pin before any Lcd_print command

I'm still a bit confused with the following tutorial:

u8 pin = (midi_package.note - MIDI_STARTNOTE)

& 0x7f

;

// turn on LED

MIOS32_DOUT_PinSet(pin, 1);

What does the "& 0x7f" ???

Maybe silly question...

But Isn't it, if I set: MIOS32_DOUT_PinSet( 0 , 1 );

Thad the first LED will light up?

Greetings

Gert

ps: TK do you mind giving me access to the programmer lounge. maybe i can do there some good idea's.

[nILS]

& 0x7f (bitwise AND) clips the pin to to 0..127.

Yes, MIOS32_DOUT_PinSet(0, 1) will light up the first LED.

[TK.]

ps: TK do you mind giving me access to the programmer lounge. maybe i can do there some good idea's.

access granted.

Best Regards, Thorsten.

[Geerinckx]

Thx nILS

Thx TK........ :wink:

[Geerinckx]

Still got a problem,

The first LCD works perfect, but whene i connect the Enable line to 1 of the J10 pins. the LCD does nothing...

Does not init at startup.

At initialisation off te application, I set all J10 pint as output open drain.

Even whene i don't connect the E line to annything (pull up connected) the LCD won't init at start up. (E line should be high)

Am I missing something?

At de datasheet for the LCD, the E line is a puls train. Right now i dano't have a scope with me to check what the E line off J15A/J15B does.

But i thought, whenever you wonna write to a LCD, the E pin off thad LCD was just high(+5V) the entire time.

Can someone point me in the right direction?

Greetings

Gert

[Geerinckx]

Found my point to the right direction....

Enable line is a select line and a kind of a clock line.

So, clamping it to ground or vss wouldn't do the trick.

A multiplexer is answer to my question i guess.

To-morrow i will test it with a 1 to 8 multiplexer.

Greetings

Gert