The CLCD digital baybus

Mat! Thanks for tuning in. Yes, I want to use the CLCD digital baybus to "upgrade" two of the I/O's on my Noritake. Both would supply power to my fans in a redundant system, and I would like LCDC to switch between them based on MM5 temps. That way, I could have the default I/O deliver 12V to an electrobus giving me dial control over my fans to regulate noise. Then, if the cpu temp gets too high while unattended, LCDC could switch to the other I/O that would supply 12V directly to the fan array (and maybe an LED), bypassing the elctrobus. Are you saying I could use LCDC as my auto switch based on MM5 temps?

Whoops, I guess I said all this already.

 

AS I said if you can find the commands that you need to send to the display to turn the GPO On/Off then us can use the action DSP->Send Commands to send that direct. E.G if the command code to turn a gpo on is 15,1 then in the commands in LCDC you would sens [##15][##1] and in the latest version [##15,1] I can't find my PDF on the display and the commands so you will need to find them out.

 

Thanks Mat.

 

In your article, you said:

"Without detailed checking I believe the GPO's on the graphical LCD's sold by Matrix Orbital work in a slightly different manor to those on the character displays, and that the circuit I use here would need some minor modifications to work with these displays."

Which parts of the circuit would need to be taken into consideration?

 

On MO's graphical controller the 5V line of the GPO switches, not the earth - so you'd need to connect the base of the transistor to the positive GPO pin and the circuit wouldn't invert the GPO's state.

Rob.

 

How does this apply to the Noritake, and would the value of the resistors change?

 

This doesn't apply to the Noritake display... if it did I'd have said it did.

Rob.

 

Sorry to drag up an old thread, but I thought it'd be better than to make a new one.

I've just done the mod an my Matrix Orbital LCD 2041-WB-V.

It has one 5v GPO, so I didnt do all the crazy stuff, just one tip31c and a 4k7 resistor. When I test it the following happens:

on/off with no load gives 12/0 volts - as expected.

When I put my lazer leds on it drops to 11v.
If I just have one cathode on (and the leds off) it drops to 10v.
With everything I currently want to controll on (3 cathodes (two inverters) and the lazer leds) there is only 9 volts coming out.

Am I trying to put too much load on the circuit? or have I done something else wrong? I'm using a 5W resistor if that is anything to go on.

I would really like to power another inverter as well once I'm finished, but unless I can keep the voltage up I don't think that will be happening.

Any ideas?

 

Hmm been a long time since i did this...

Very little power is dissipated in the resistor - 5W over kill by a long way but it won't hurt.

Soo... if you're getting less than 12V either the missing voltage is being dropped across the transistor (Collector to Emitter) or your supply voltage is failing. Do you have a multimeter? Measure both if you do and see what's going on...

let's assume the voltage is across the transistor, that means it must be getting fairly hot (3V at an amp or two) - maybe it's a heating issue? Try popping a sink on the transistor?

The only other thing that springs to mind is that the resistor on the Base line may be too high and you're not putting the transistor into a digital state - try swapping your mega 5W resistor for one of a slightly lower resistance?

Rob.

 

THanks, I'll give all that a go, my supply rail is rock solid at 12v. I've got a Truepower 550W EPS12V so it shouldnt be having any problems. I'll chech the tranny and the resistor and see what I come up with.