SPC900 LXmod yesyes style ;-)

[Gina]

Resoldered the USB data wires for the webcam and now detecting the camera USB port.

Bus 001 Device 024: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

Bus 001 Device 023: ID 0471:0329 Philips SPC 900NC PC Camera / ORITE CCD Webcam(PC370R)

Bus 001 Device 022: ID 1a40:0101 TERMINUS TECHNOLOGY INC.

BUT the webcam software is still reporting "No Device Detected"

[yesyes]

What OS are you running this on? I've had a few issues with the SPC900 driver on Win7 x64. I have to uninstall and reinstall the driver occasionally.

[Gina]

What OS are you running this on? I've had a few issues with the SPC900 driver on Win7 x64. I have to uninstall and reinstall the driver occasionally.

I'm running Linux Mint 9 and the webcam software is Cheese. This combination runs the SPC900NC perfectly. I have another (unmodified) SPC900NC and that runs fine as did the other one before I did the mod. No separate webcam driver required.

[pete_l]

Nice neat job, btw RS232 isn't 5v more like -12v to +12v.

If you use one of those cheap USB-Serial (I won't call it RS232) then you get 0 and +5V levels. If you know what you're doing you can therefore cut out the level shifting circuitry from the standard LX mod explanations and feed the control signals straight into the logic. You'll probably have to use inverted (or uninverted - whichever is the opposite of the usual LX config) option in WxAstroCam but otherwise it works very well.

I've done exactly the same mods and it works fine. One box, one USB and a nice neat, cheap solution.

[Gina]

Well I don't know what I did but it's working!

Here's an image captured with Cheese using it's original lens.

[Tom How]

What is the camera actually for Gina? Guiding or actually imaging?

[yesyes]

It can be used for both, even without the mod. The LX mod allows longer exposures which makes it a better guide cam. You can also take long exposures of deep sky objects although this will of course not reach the quality of a DSLR or even astro CCD camera.

The switch on the modded cam puts it back in normal mode, disabling the mod. You can then use it as a normal webcam to record video of planets for example.

[Tom How]

My point being, if you are using it for guiding then amp-off is a bit of an overkill. Actually it is worse, because it add complexity and noise.

If you want it for imaging then I wouldn't recommend the simple zener power reduction amp-off mod. It is better to add the extra couple of components to maintain the substrate bias whilst dropping power to the chip.

[Gina]

What is the camera actually for Gina? Guiding or actually imaging?

I'm planning to use it for imaging.

[Tom How]

Considering the effort you've gone to, and your obvious abilities with a soldering iron, you might find this old page useful

Direct Bias Amp Off Experiments for SC1 and SC3 modified Toucam webcams

[Gina]

If you want it for imaging then I wouldn't recommend the simple zener power reduction amp-off mod. It is better to add the extra couple of components to maintain the substrate bias whilst dropping power to the chip.

Do you have the circuit for this or a link to it, please? I'd be quite happy to add a couple of extra components to get a better result.

One thing I have noticed is that the camera gets quite hot so I can see why people add a fan. Cooling to -20C might be OTT but having the camera heat itself a long way above ambient would not be very good. I know this is a problem with DSLRs too.

[NickRose2006]

I have some parts question dealing with the PCB board parts.

1.) The parts needed are 5 10k resistors, 3 BC547 transistors, 2 1N4148 diodes, and 1 11Volt Zener, is this right?

2.) With the 10k resistors should they be 25Watts? Like this one: CF1/4W103JRC: VARIOUS: Passive Components

3.) Since the place that I'll buy my pieces from does not have the 1N5348 would any 11Volt Zener work? Jameco Electronics - Electronic Components Distributor

4.) What is the metal piece near the right edge for and is it a cut piece from one of the transistors?

[Tom How]

see here http://astro.neutral.org/eq/ampoff.html Gina - although as far as I know nobody has bothered to to it to an SPC900 so it might require a bit of ingenuity and experiment.

I initially applied this method to webcams quite late in the "webcam astronomy" revolution and it got a bit lost with the advent of the inexpensive dedicated imagers that started to appear about 4 years ago.

Mind you, made to work it is great, and yes, you do need a fan.

examples from 2005

M27 Dumbbell nebula Outer Halo with SC3 modified toucam webcam

IC 63 Bright nebula in Cassiopeia SC3 Webcam- The Curdridge Observatory

http://astro.neutral.org/images/20051002_vdb142.jpg

NGC206 Sc1 and Sc3 webcam images at the Curdridge Observatory

M31 clusters and globulars with SC3 Toucam

[Gina]

I have some parts question dealing with the PCB board parts.

1.) The parts needed are 5 10k resistors, 3 BC547 transistors, 2 1N4148 diodes, and 1 11Volt Zener, is this right?

Yes

2.) With the 10k resistors should they be 25Watts? Like this one: CF1/4W103JRC: VARIOUS: Passive Components

0.25w

3.) Since the place that I'll buy my pieces from does not have the 1N5348 would any 11Volt Zener work? Jameco Electronics - Electronic Components Distributor

Yes, I think so.

4.) What is the metal piece near the right edge for and is it a cut piece from one of the transistors?

It's a wire link.

[Gina]

see here Direct Bias Amp Off Experiments for SC1 and SC3 modified Toucam webcams Gina - although as far as I know nobody has bothered to to it to an SPC900 so it might require a bit of ingenuity and experiment.

Thanks That link refers to reducing the supply voltage to the webcam - looks like the SPC900 mod is more sophisticated.

yes, you do need a fan.

Suspected that.

[NickRose2006]

Yes0.25wYes, I think so.It's a wire link.

Where does the wire link come from, is it any type of wire? Also with a multimeter would this work fine for the project: https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2131127_-1

[JKB]

Well here is my version. Many thanks for decent images etc.

1st is circuit board

2nd all connected inside box

3rd finished.

Works, but will try it properly later in a dark place (no chance of the heavens due to cloud!)

Cheers Jamie

[G6RAR]

Hi everyone,

Just a short note to say this a very good thread into SPC900 mods.

Keep up the good work.

Also, Morgan Computers are selling SPC880 for £7.50 each.

If you include the flashing to SPC900 you get a SPC900 for £10.00

Not bad value at all.

Cheers

Dave

[Gina]

Looks like I should have waited a while - only just bought my second one (at about twice that price)! Oh well, that's the way it goes...

[yesyes]

Hi everyone,

Just a short note to say this a very good thread into SPC900 mods.

Keep up the good work.

Also, Morgan Computers are selling SPC880 for £7.50 each.

If you include the flashing to SPC900 you get a SPC900 for £10.00

Not bad value at all.

Cheers

Dave

Thanks Dave... ;-)

Regarding SPC880s from Morgans, they have a special half price offer this week only (according to their email newsletter). So anyone who does not have enough of these, buy quickly.

I bought 5 of them when they were still £5 each.

[Gina]

Just ordered a couple more while they're on special offer. That's 4 of them I'll have. Should be enough

[Vlad]

A 120 skywatcher apo. Forget all else. Take my word, or find out the hard way. I did! Take a look through one first, somebody around you will have one. You'll never regret it.

Good luck

[Gina]

A 120 skywatcher apo. Forget all else. Take my word, or find out the hard way. I did! Take a look through one first, somebody around you will have one. You'll never regret it.

Good luck

Very nice but what has that got to do with the topic - SPC900 LXmod?

[yesyes]

i was wondering that too.... ;-)

[G6RAR]

Probably dyslexic fingers syndrome.

I must admit that I suffer from this some times.

Anyway, bought 2 more SPC880/900 from Morgan.

So I'm up to 4 also.

1 modified for LX and Amp Off, seems to work in testing.

It's in a larger box than others have used as I will be fitting peltier cooling and fan.

It's taking back stage at the moment as I'm working on a motor focuser (DC and stepper) and C# software.

Cheers

Dave