VFD2041 and all I get is a cursor

NevilleWoo · Post by **NevilleWoo** » Mon Aug 05, 2002 2:50 pm

I just bought this from a colleague that never ended up using his but i cannot get it to work. I have modified the cable so it sends 5volts and powers up the VFD just fine. All i get is a blinking cursor. By default its set to 19200 and i checked that my BIOS and XP have these enabled and set at 19200,n,8,1. I have gone out and bought a standard serial and null modem cable but still nothing even when i try to run the MO demo and LCDC s/w. Hyperterm also fails to connect to it.

However when removing the null modem cable from the back of my pc i notice the VFD turns off or doesnt display the cursor any longer.

I have tried com2 and even different baud rates but alas, all in vain.

Please help before I lose the last few strands of hair left !!!!!

Neville

Post by **Cheese** » Mon Aug 05, 2002 5:38 pm

The null modem cable is your downfall...

You need a direct connection from pin 2 to 2 and from pin 3 to 3, with a null modem cable these lines are switched.

Rob.

NevilleWoo · Post by **NevilleWoo** » Mon Aug 05, 2002 6:14 pm

Thats what I thought so i went to Compusa and got a serial 9pin male and 9pin female,
typically the same cables used to extend serial mouse etc but that didnt work either.

NevilleWoo · Post by **NevilleWoo** » Mon Aug 05, 2002 7:19 pm

Cheese, I got so frustrated that i stripped that new cable i bought and cut all wires and soldered only those as indicated in the diagrams .ie pins 2,3 & 5. But i still just get a flashing cursor. Am I suppose to get an "initialising " screen when powering on ?
From the moment its gets power it just shows the cursor.

Thinking that there might be something wrong with my pc i moved the setup to an older P3-600 and still got the same results.

Any other tricks ? Do you think the guys at MO will RMA this even though i never bought it directly from them ?

Thanks

[ This Message was edited by: NevilleWoo on 2002-08-05 20:06 ]

Post by **Henry** » Tue Aug 06, 2002 11:29 am

The blinking cursor is a good thing, meaning the VFD has been powered up and all is well... make sure you have nothing else using the serial ports, like digital camera or palm pilot software, then load up software like MOGD or Alpha Demo from our CD and test it, doing basic stuff like turning on and of the display, or sending some text.

NevilleWoo · Post by **NevilleWoo** » Tue Aug 06, 2002 1:15 pm

Henry, I have tried using Hyperterm, MOGD and the other sharewares but no luck. I just cant seem to talk to the device at all. I dont have any IRQ conflicts and no devices like cameras attached to my ports. I can check on the status of my 2 com ports and they display as 19200,n,8,1. I also used another pc but that didnt help.

It should be as simple as plugging into com1, checking the right baud rate, power is right at 5volts and then using any program to talk to it ? Is there anyway to force an initialise of the device ?

Thanks for the responses so far.
Much appreciated
Neville

Post by **Henry** » Tue Aug 06, 2002 1:36 pm

The display does not need to be initilized... you send test to it, you get text on the screen... the display is factory set to 19.2K... the display is powered up, we know that, it's not blown up or anything, the only thing I can think of is this... try anothe serial cable and try another system.

NevilleWoo · Post by **NevilleWoo** » Tue Aug 06, 2002 2:25 pm

When you say serial, do you mean a typical rs-232 used lets say to extend a serial mouse cable ? I'll see if i can go out and get another cable

Post by **Henry** » Tue Aug 06, 2002 2:45 pm

straight through serial... pin 1 to pin 1, pin 2 to pin 2 and so on...

NevilleWoo · Post by **NevilleWoo** » Tue Aug 06, 2002 2:49 pm

Why is that when i disconnect my cable fro the back of the VFD com port the display turns off ? Doesnt that means its detecting the cable ?

Post by **Henry** » Tue Aug 06, 2002 2:51 pm

honestly I don't know there... if it's not a straight through cable, it my be gettign some strange signals from the system...

NevilleWoo · Post by **NevilleWoo** » Tue Aug 06, 2002 5:17 pm

OK well i finally found a straight thru cable @ RadioShack and its called an RS-232C cable. Back of the box clearly indicates that pins 2,3,5 lineup to each other but I still have the problem.

My first character on the display is a solid block and the 2nd one is a flashing solid cursor.

I also checked that i was plugging into the correct serial ports aswell.

Any other ideas ?

Oh this time if i remove the cable from the back of the VFD the display does not turn off.

[ This Message was edited by: NevilleWoo on 2002-08-06 17:18 ]

[ This Message was edited by: NevilleWoo on 2002-08-06 17:47 ]

Post by **Mat-Moo** » Wed Aug 07, 2002 2:50 am

Have you used the com ports before for anything else? Not something silly like they are disabled in bios (Although I don't think you'd see them in windows if that was the case). Can you try it on another pc with hyperterm?

NevilleWoo · Post by **NevilleWoo** » Wed Aug 07, 2002 4:55 am

Matt i now have tried them on 3 different computers, also tried different ports and even different baud rates.

I know for certain now I have the right cable. Yes Both com ports are enabled as usual at IRQ4, 3F8 and com2 IRQ3, 2F8

Doing a "mode com1" tells me that they are at 19200,n,8,1.

I'm assuming i dont need to fiddle with Flow Control - Hardware or Xon/Xoff right ?

Using any s/w does not send anything across. If i cant connect via Hyperterm i know the others like MOGD wont work but i allways try then just in case - but still no joy.

The VFD is basically 2 seperate pcbs joined. How can i tell that the com port is in fact receiving data ? Without voiding any warranty ......

NevilleWoo · Post by **NevilleWoo** » Wed Aug 07, 2002 3:21 pm

Any other ideas ? Pleeeeeeeeeeeeeeeeeeeeze.............

Neville