Problems

[Roybie]

Hi, I got this as a gift for Xmas, soldered it all up (I think) ok. But there is nothing when I plug it in to the TV or anything.

I've had a play with a multimeter, and it seems like it's all connected ok. The weird thing is, there is voltage across the outputs unless I plug in the audio and/or video cable, then there is nothing. I dunno if this is normal or not, but anyway I can't figure out what is wrong or how if at all I can fix it!

Any ideas?

Cheers, Roy

[Michael]

Have you looked at the Troubleshooting section?
http://nootropicdesign.com/hackvision/build/#troubleshooting

Are you using a 9V DC center-positive power supply? It's very important that it be center positive.

Any sound output at all when you power it on while connected to TV? You should hear a "blink" sort of sound at power up. That would tell us that it's running.

[Roybie]

Yeah I've looked through all the troubleshooting, and have a correct power adapter.

No sound or anything. I also can't get Arduino IDE to upload to the chip (I have the correct cable and the correct COM port and stuff selected), so maybe the chip is dead I dunno. Is there an easy way of checking where the problem is?

[Michael]

Hmm. I'm sure you have the chip oriented correctly, right? Every chip I send out has been tested so I know they are loaded with the bootloader and games.

Do you have an Arduino you could put the chip in and see if you can upload a simple program to it? The chip has the normal Arduino bootloader on it (just like a Duemilanove). You can always load the original Hackvision firmware back onto the chip.

It sounds like maybe there is a short circuit somewhere. I'd be happy to look at any high resolution photos you send me.

Where are you located (what country)? Did you purchase directly from me or one of my distributors?

-Michael

[Roybie]

Unfortunately I don't have an Arduino board I can use to test.

I'm in the UK, not sure where it was bought from since it was a gift. I might assume Cool Components though. But I could find out for sure if needs be.

Here's a couple of pics, thanks.

TOP
BOTTOM

(I get 403 when I try to click those links, but they are there and accessible!)

Roy.

[Michael]

I also get 403 when trying to access them. You can email them to me at michael@nootropicdesign.com.

Yes, Cool Components is my only UK distributor.

The only other thing I can think of is that the PCB has an error of some kind. I pay my fab house for electrical testing, so there should not be any bad PCBs, but I suppose it can happen.
No matter what, I'll make sure you get a working Hackvision.

[Michael]

[Ok, I got to the images by pasting the address]

[Michael]

I don't see anything obviously wrong with your soldering. Since you are in the UK, you'll need to solder the PAL jumper as described in step 3 (unless you are sure that your TV can handle an NTSC signal). I don't think this is your problem though, because you'd get sound and you'd be able to program the chip using the FTDI cable.

I would use your multimeter and make sure you have 5V across the VCC and GND pins on the ATmega chip. The datasheet here shows which pins to check (7 is VCC, 8 is GND, 22 is GND). http://www.atmel.com/dyn/resources/prod_documents/8271S.pdf

Some of your solder joints look a little light on solder, especially the FTDI cable connector. You might want to reheat/resolder some of your joints just to make sure they are good.

Also, I have to ask if you had the FTDI cable oriented correctly when connected -- forgive me if that's an elementary question.

[Roybie]

I thought this seemed a bit weird earlier, I should have said, it seems like I have about 8V across those pins (I had already found that datasheet and checked that )

I also have 0V across R2 and R3.

I was using the hackvision with an easycap usb adapter to play through the computer so I didn't bother soldering the PAL jumper. Though I tried with a TV too just in case.

As for the FTDI cable, I assume the green wire should be on the side where the board says green?

[edit] just checked again and now it's about 5.8V :S

[Roybie]

Interestingly, there is voltage across the output of the chip and when I press reset the voltage drops and then comes back up. Doesn't this sound like it's working?

But as soon as I plug in the audio and/or video cables to the board, there's nothing.

[Michael]

Ok, Hackvision is for televisions, not this easycap device. I seriously doubt if the video signal emitted by the ATmega is going to be properly understood by the easycap thing. Please solder the PAL jumper and try a television.

When you say the "chip output" goes to zero when the cables are hooked up, what output do you mean exactly? The voltage across the center of the video output and the barrel (gnd) of the video output? I would expect it to go lower since there is an internal 75 ohm resistor built into a TV, but you aren't going to learn much by measuring this voltage. The voltage on the video output will change very rapidly. It will be 1 volt when a pixel is being drawn and 0 for black. At 60 frames per second, and over 13000 pixels per frame, the voltage is changing over 780000 per second. A multimeter is not going to help you.

The voltage across VCC and GND on the ATmega chip should be almost exactly 5V. The voltage regulator should be outputting 5V. Please measure the VCC and GND on the chip, as well as the voltage regulator.

Yes, on the FTDI cable, black to "blk", green to "grn". There should be 5V supplied by your USB to the chip. VCC and GND on the chip should have 5V across it.

[Roybie]

The voltage across the regulator (the 'bottom' two horizontal pins) is like 4.8-4.9V so this seems about right.

But across the VCC and GND of the chip is about a volt higher, 5.8-5.9V, same if I measure over the C2 capacitor next to the regulator.

[Michael]

I think the only thing I can suggest at this point is to
a) resolder your FTDI connector and try to use the Arduino IDE to upload a simple program again. Choose "Duemilanove" from the board menu.
b) solder the PAL jumper and connect to a TV.

If there's still no luck with either, then I'd say your chip got fried or the PCB is bad. Email me and we'll talk about replacement.

[Roybie]

Thanks for the patient help. I'll try that and get back to you.

Roy

[Michael]

...one more thing to try: remove the chip and re-insert it.