VGA pinout difference

PVJohn

I'm vould like to use a module that I built as per Prop Demo board rev. C to try some Hydra projects and I noticed a difference in pins 9 and 11. Do I need to disconnect pin 9 from 5V and connect pin 11 to GND, or it will work like this.
Thanks,
PVJohn

AndreL

Could you give more detail? What are you trying to do? Connect something you made to the hydra's VGA port?

The hydra's VGA port uses the following pins in the following way:

1 - red
2 - green
3 - blue
4 - NC
5 - GND
6 - GND
7 - GND
8 - GND
9 - NC
10 - GND
11 - GND
12 - NC
13 - HSYNC
14 - VSYNC
15 - NC

So whatever you do don't connect VCC to any of the ground pins, other than that, the NCs are not connected to anything, so if you do put a GND or VCC on any of them as part of your module and you don't want to mod it, that should be ok, since those signals go nowhere in the hydra.

Andre'

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PVJohn

I made a little and simple PCB with VGA connector (only) on it. I've done it as per Demo board rev. D http://www.parallax.com/dl/docs/prod/prop/PropDemoDschem.pdf
On that schematic pin 9 is connected to 5V and pin 11 is NC. As you mentioned in HYDRA schematic pin 9
is NC and pin 11 is connected to GND. I haven't tried it yet, and I would like to ask is it safe for my monitor to connect 5V
to the pin 9 if it has to be grounded? ·Is it going to work if pin 11 is NC like it is now on my PCB?
Thanks.

PVJohn

PS.
FYI, there's a little error in the HYDRA book on page 161. For SDA_CART signal Propeller pin should be 38/P29.
I really like your book, it's very usefull.

PVJohn

Just a little correction:

"I haven't tried it yet, and I would like to ask is it safe for my monitor to connect 5V to the pin 9 if it has to be grounded?"

Should be:

I haven't tried it yet, and I would like to ask is it safe for my monitor to connect 5V to the pin 9 ?

PVJohn

AndreL

Thanks for the typo.

As far as the VGA stuff. The pin 9 is a no connect as far as I know, the only pins that are used for other stuff are 11 and 12 which are part of the ID spec, usually 11 is ground and 12 is left NC. Pin 9 is not supposed to be grounded, its NC, but chances are if you ground it or connect it to +5 its not going to hurt, but you never know if a monitor has something connected to it. I am not sure why parallax put +5 on pin 9. It could be because some LCD vga display uses it for power or some kind of detect, etc.

But, typically this is a NC pin. However, since it is a NC pin, technically nothing should be connected on the monitor side and no damage should occur, but you never know unless you try.

Andre'

Newzed

I have pins 6-7-8-9-10 all grounded on my VGA module and it works just fine.

Sid

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sid Weaver
Don't have VGA?

Newzed@aol.com
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PVJohn

I can't find an example on HYDRA CD that use VGA output. I tried some examples from Parallax hoping that they'll work, since they are using the same pins, but they didn't. Flipping the "VGA enable" switch also didn't help. What can I try next?
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PVJohn

AndreL

Hmmm, should be mentioned somewhere in the book, can't find the page right now. But, try "vgachrs_010.spin"

That's the top level file. Just program it in, have the VGA switch on, and have the monitor plugged into the port and you will see the character dump.

ALSO, there is a cool test program I wrote that tests every single bit of the prop and hydra including VGA and NTSC at the same time, its called:

hydra_test_rev_a.zip

Inside is the test software that you can explode as well and use as a test.

Andre'

PVJohn

I have tried vgachrs_10 and all I get was "OUT of range" message on my monitor. Why I can't use any of propeller samples? Different EEPROM or/and something else?

PVJohn

AndreL

That's bizzare, might be somethnig specific about your monitor. But, that vga demo is basically the EXACT same code chip wrote initally, and the hardware simply connects to the VGA port, shouldn't be any kind of of range stuff. The only thing, possibly is its some kind of sync polarity issue. But, the vga is so generic. I am not sure what that won't work. Try another VGA monitor and let's see what happens. But, it works on all our sample monitors here from 15" to 22" all brands about 25 of them. The hardware has notning to it, just the byte connected to the pins. The NCs and GNDs are where they are supposed to be as per the VGA spec. I still do not see why chip was setting a pin to +5, that's not part of the normal spec. The resistor network generates voltages in the proper range, so that shouldn't do anything wrong either. But, at least the monitor is seeing the signal.

What about the test program hydra_test_rev_a.zip, do you get the same out of range issue?

In any case, try another monitor and if you are using a cable that is not connected to the monitor, try another cable. And also, take a look at the monitor setup and the sync etc. settings in the setup, you might need to change something there and flip it around or change a voltage setting.

Andre'

PVJohn

Andre, thanks for a detail explanation. My confusion is generated from the fact that the same monitor works fine with Prop Demo Board rev. C. I have two boards (HYDRA and Prop Demo Board rev. C) up and running at the same time and when I connect my monitor to the prop board I have a picture. Then I plug it to the HYDRA board and there's nothing on the screen other than that error message. I'll try to play with the settings on the monitor and see if something will change. It's NEC 15'' LCD monitor Multisync 1545V. I have two of those (for extended desktop) and I'll try another one. I'll let you know. Thanks again,

PVJohn

AndreL

Ironically, I am using 2 nec multisyncs here, a viewmate and a micron, all work of course.

Andre'

PVJohn

No luck for me! I have tried 2 files that you suggested, but that annoying error message was keep on coming out. Both monitors worked fine with Prop Demo Board and 2 examples. One was hi_res_test and the other was with keyboard input at lower resolution. Nothing worked on Hydra board. I had a TV and Game pad disconnected when I ran Hydra test code, and there was nothing on VGA. A little red debug LED was blinking al the time. When I tried to run 2 Hydra examples on Prop Demo Board I was getting the same Out of range message. Hopefully it didn’t burn anything on the board.I have more pics to show if you want to see, but for now I’ll upload only. I have tried to change settings on both monitors, but it didn’t help at all. And for the end just to mention that “VGA enable” switch was in ON position. Flipping it didn’t help either. Any other suggestion? Thanks again for you help.
PVJohn

PVJohn

Here's a photo of a test setup.
PVJohn

Mike Green

The "Out of Range" message might indicate that the vertical or horizontal scan rate is incompatible with the VGA monitor. Sometimes you can use a different Propeller VGA driver with a different scan rate and it will work. Chip's 1024 x 768 resolution text driver uses 57Hz at 1024 x 768, 75Hz at 800 x 600 and 69Hz at 640 x 480 resolution. One VGA monitor I tried it with could only handle the 75Hz resolution. Newer monitors tend to be a bit more flexible.

AndreL

You can't really hurt anything, both chip and my boards have current limiting resistors (100 ohm or so) in line with the syncs, so no matter what things aren't going to hurt. Like Mike said, it seems like a sync issue, has nothing to do with the hardware, its just a PROP and a D/A, that's it conencted to the VGA port.

Andre'

PVJohn

What can I try next? Is there any soltion other then bying a new monitor ?
Thanks,
PVJohn

AndreL

Its just software, the timing needs to change that's all to make your monitor happy. If you take the slower 640x480 character driver that chip made, then make sure it works on the demo board with your monitor then load it in the hydra changing the port to match the hydra VGA port, make sure the VGA enable is on. Then it should work.

Andre'