Doing the SC1 and amp-off mods (SC1.5) on a Logitech 3000/ 4000 Pro.

Introduction and Copyright - Ensure that you read the copyright before proceeding.

This page is a quick summary of the mod technique I use for the Logitech QuickCam SC1.5 - this is based on a quickcam 3000, though the 4000 is the same process. If buying a 4000, note that the ccds used are sometimes the far less sensitive Sharp LZ series ccds and although you can still mod them, the results will be disappointing. This article was originally written for UKAstroImaging

Firstly, I should mention a couple of names:

Steve Chambers - for those of you who don't know, the 'SC' of SC mods. Steve is owed (whether people know it or not - owners of ATiK and SAC cams, take note...) a huge debt of gratitude by amateur imagers worldwide for his ground breaking work into modding the humble webcam. This work is the intellectual property of Steve and other members of QCUIAG and should not be used for making a profit. Steve has written the following copyright clause, and I have been asked to include it:

Copyright.

The novel information on these pages is copyright. It is forbidden to use this information for profit. Should you receive any money as a result of performing this mod or selling a modified camera send the money (less parts) to www.msf.org.

Over the last year I have received some requests from people who are looking for a way round these restrictions. I would like to take this opportunity to specifically state that it not OK to give modified cameras away free with other products nor is it OK to charge people for you time when going mods for others.

Any individuals of companies wishing to produce commercial products based on these modifications please contact me directly smunch at clara dot co dot uk

Please abide by these restrictions, as this will ensure that future developments can disclosed in the same way.

Steve Chambers

Another quote from Steve equally applies:

Warning!!!!!!!!!!!!!!!!!

I do not guarantee that your camera or PC or yourself won't get damaged as a result on making these modifications or that the software won't do the same. I won't even guarantee that if you get it right it will work!

What I can guarantee is a big grin the first time you pick up a deep sky object with a web cam.

Martin Burri Who's modification techniques are the ones I use personally. Martin has also asked that I link to his FAQs Page where you will find additional help.

I'm also endebted to many more members of the QuickCam and Unconventional Imaging Astronomy Group

OK - to kick off...

Before starting, install the cam and check that it works.

Tools you would be advised to purchase - I personally consider them all to be essential. You really can't do without the hot glue though.

• A hot glue stick (gun - I just use a stick and cut a bit off the end and melt it in using a soldering iron)
• A 0.5mm tipped soldering iron (15W max)
• A Scalpel or fine craft knife.
• wire cutters/ strippers.
• A magnifying helping hand.

Components (inc Maplin part nos)

SC1:

• 4066 Bi lateral switch IC (logic) QX23A
• 4x 15k ohm resistors M15K
• very fine wire (as fine as you can find - cut apart an old usb cable - maplins sell nothing appropriate, though Farnell Inone do)
• A 14 pin dil socket BL18

Amp-Off

• 10nF disk capacitor QX00A
• 220 ohm resistor M220R
• 10k resistor M10K
• 39k resistor M39K
• BC327 PNP Transistor QB66
• BC337 NPN Transistor QB68
• BZY 6V2 Zener Diode QH09K

The Mod

1. Getting the cam out of it's case.

Unscrew the small black screw on the underside towards the rear.

Using a small screwdriver, gently prise around the cam's join and it should come apart relatively easily - the only slightly tricky bit is the bit directly over the lens - you may need to apply quite a bit of force to pull this apart - it's pretty sturdy - I haven't managed to break this lug yet.

If you follow this method to the end, you won't need the case anyway. I always re-house a QC3K as it's ccd is a fair way back inside the camera and this effects the amount of focusser travel you get meaning that with a newt it may not come to focus. Mounting the camera in a case is straight forwards and brings the ccd close to the surface of the case.

When the 'ball' pops apart, the circuit board, attached lens and the top bit with the switch/ mic will come out. There are two connectors to the switch/ mic piece - just gently pull these out of the sockets on the board.

This leaves you with the cam's internals.

2. Cutting and baring the track (points A and B below).

With the camera held firmly in the helping hand, you need to cut the track that leads to the second pin from the left of the CXD chip at point B in the below image. In Martin Burri's original mod, he cuts the track around half way between the CXD and SAA chips. I cut the track close to the pin at point B for several reasons:

• You can bare more of the track to solder one of the wires to
• still solder to the pin at point B
• cut the track with no other tracks near by

In the below image the track has been cut. I do this using a scalpel. Push the scalpel through the track and lift it to one side to ensure the track is broken. This is tested by using a continuity tester between the SAA pin and the CXD pin that were previously connected. Take care not to lift the track all the way off back to the SAA chip - if the track peels away, trim the peeled section off taking care to leave enough track to solder to.

Also in the below picture I have used a scalpel to clear the paint over the track to expose it at point A. A continuity tester between the track and SAA pin is used to ensure that the track is bared.

3. Lifting the pin and baring the via (points A and B below)

It is possible to lift pin 4 (A) by simply easing a scalpel under it, starting on the via side, and alternately levering the leg away by getting the scalpel tip between legs 4 and 5 and 3 and 4. To begin with, I use a solder wick to lift as much of the solder off the leg as possible. This may be the most tricky part of the mod - be very gentle and take your time. The leg is very thin at the top and the chances of breaking the leg off are quite high. I intend to put an additional article on about what to do if you break the leg off - all is not neccessarily lost if you do. You do not need to lift the leg as far as I have done here - as long as it pokes over the top of the chip, that's good enough.

Once you have lifted the leg, use the tip of a scalpel to clean the via at B - it usually has dye over it.

When you lift the leg, it may come away with the track that it is soldered to. As long as the via is still there, this is not a problem.

Points C and D are the other two connection points.

Now you're ready to connect the wires.

4. Connecting the wires.

This requires a steady hand - the second picture below includes the tip of a biro to show scale.

I connect the wires in the order:

• pin 9 (orange wire)
• bared track (green wire)
• pin 4 pad/via (yellow wire)
• pin4 (blue wire)

Test using a continuity tester to make sure all the connections are good and that there are no shorts. Seal with hot glue immediately - the connections are quite weak and will not stand up to any rough treatment until sealed with glue. I cut a little off the glue stick and melt it over using a soldering iron (do this in a well ventilated area - it stinks).

at this point you can re-connect the wires - pad4 wire to pin4 wire, pin9 wire to stripped track wire - plug the camera in and test that it works.

5. Making the long exposure and amp-off circuits.

First a little about the components. The 4016/4066 Bi-lat switch logic IC must be oriented correctly. Both the DIL socket and the IC itself will have a small impression in one end. Looking down on the IC, the legs are numbered as the below diagram. This is the only component in the LX module that must be oriented correctly. In the case of the amp-off module, the transistors and zener diode must be oriented correctly.

The below image is taken from Martin Burri's website and shows the circuit diagram for the Long Exposure modification. Note: This is copyright information, reproduced with the kind permission of Martin and is coverred by the clause detailled above.

This diagram is also from Martin's website and is re-produced under the same conditions.

Building the LX Module.

Don't let the circuit diagram put you off - it's really quite straight forward.

I use a 14 pin dil socket to protect the IC which I insert as a last step, after the rest of the camera is built. I think you could probably do the mod without the socket and as the IC is only 40p or so, it wouldn't be a huge problem if you burned one out, but I always use a socket to be on the safe side. It's a fair bit of work to undo if you do burn out the IC.

Remove pins 8, 9, 10 and 11 with a side cutter. Get four 15K resistors (I've used Maplins .6 W ones but any low power resistors will do - Martin says that the resistance isn't crucial, I've used 10K ones myself and the results weren't that good - whether this was down to the resistors or other factors, I don't know) and make a small loop in the wire on one side, close to the resistor. Doing one at a time, put these over legs 2,3 5 and 13 and solder them on. Wrap the other end of the four resistors together and solder. Trim 3 and bend the wire on the fourth over to touch pin 14 of the socket and solder it on. Attach a wire to the point where the four resistors are wrapped together - this will be the +5vDC line. Strip about 1cm of insulation off the end of another piece of wire and tin it along this length. Gently bend pins 6 and 7 together and solder them. Lay the 1cm of exposed wire across from the join of pins 6/7 and pin 12 and solder the wire to all three pins. This is the ground connection. The finished module should look something like the below picture.

Building the amp off module.

Make small loops in the wires of the zener diode - take care, it's easy to break the wires off a zener - and attach it across the emitter and collector of the BC327 oriented so that the marked end of the diode is connected to the emitter which holding the transistor upright and facing the flat side towards you, is the right hand leg. Attach the 39K resistor from the remaining leg of the BC327 to the collector of the BC337 (left hand leg if the transistor is held in the above described orientation). Wrap the legs of the 220R and 10K resistors together and attach the joined end to the base of the BC337 (the central pin). Connect the capacitor between the collector of the BC327 (which the unmarked end of the diode should be connected to) and the emitter of the BC337. Also connect a wire (ground) to the emitter of the BC337. To the end of the 10K resistor which is currently unattached, connect a wire for the +5vDC supply.

When you are finished you should have something like the below.

6. Cutting the CCD pin and attaching wires.

From the above amp-off diagram, you'll see that the CCD pin 8 and pad need to be separated. With a toucam this is simple enough as the pin rests on the surface and can simply be desoldered. With the QuickCams and Vestas, the pin goes through the board and it is easier to cut through the pin where it goes into the board. I use a scalpel and slowly and gently saw through the pin and lift the remaining pin with the tip of the blade. The wire connected can be run through a small hole in the board used by a locator pin on the plastic ccd housing which can be cut off. The pad wire can be connected to the remains of the pin on the other side of the board.

A is the cut pin, B is a small aluminium plate which gives a small bit of cooling to the ccd, C is the CCD Sony ICX098AK.

In the above picture, the plastic locator pin has been cut off at point A to allow the wire to use the hole it previously passed through.

At this time, it's a good idea to sort out the overly bright LED. In the priginal article, Martin Burri suggests painting over it - this is perfectly good and works well enough, but there is no reason why you shouldn't desolder and remove the LED. The following shows the location of the LED on the CCD side of the circuit board on the opposite side of the CCD to the cut pin at A and the board with the LED removed.

Now I attach the wire to the lifted ccd pin, first running it through the old locator pin hole, then seal the connection in a tiny dot of hot glue, to insulate it.

Next, you turn the board back over and fix a wire to the remaining piece of ccd pin effectively making a join with the pad - the purple wire in this picture.

When this wire is connected, again use a small dot of hot glue to seal it in place and connect the two ccd pin and pad wires together so that all wires are connected. Re-attach the ccd housing - you may need to clean the ccd window with a small amount of isopropyl alcohol and a cotton bud. Now, with all the broken connections reconnected, you can test the webcam to ensure all is still working fine.

7. Attaching the modules

Take your time attaching the modules and wires - it's all getting a little tight now, and you could easily lift off one of the wires, create a short or burn through some insulation.

First attach the amp-off module. I find it fits neatly over the white plastic connector on the edge of the board, but how you mount i will depend largely on how you intend to house the camera. I'll be adding another article once this one is finished. In the below picture the amp-off module is at the top with the two wires attached. It's a good idea to trim the wires as short as possible at this stage to reduce the amount of noise you pick up. Don't connect the power cables yet.

Also in the above picture you can see the long exposure module. The four wires from the circuit board attach as in the circuit diagram to pins 1 to four.

When these are all attached, you can link the power cables and a fan (if you intend to use one). I always join the power cables at the amp-off module then run the ones on the module to the usb connector for power - don't connect these two just yet.

When these are attached, you can connect the parallel cable. I use high quality quad cable for this mod - each of the cores is individually shielded meaning that noise is reduced to a minimum across the conductors. The connections are made to pins 5 and 13 of the IC and the amp-off module 220R resistor. When you're done, it should look something like this.

Next thing to do is to seal with hot glue any of the components that may create a short when the camera is put together.

I always ensure that the transistor legs in the amp off module are well insulated with hot glue - they are quite flexible and it is easy to create a short later. The earth on the parallel (the shielding) could also cause a short, so blob this with glue. Use the glue sparingly as it's difficult to remove if anything needs checking or testing.

The power connections to the usb can be made now - the usb connector has a black and red wire comming in to one side - red is +5vDC and black is 0vDC.

Add the IC - cut legs 8, 9, 10 and 11 off and push it into the socket - you may need to adjust the spread to suit the socket's width. Once the IC is in, melt a blob of glue onto the SAA (don't allow the SAA to overheat though) and stick the chip on.

There we go - the cam's all done.

Connect the parallel socket as in the above circuit diagrams and it's ready to test.

I roughly focus the cam in webcam mode, attach the parallel connector, stick it in a draw, turn the lights off (a red table cloth is over the slight gap in the draw end, hence the colour. This is a 10 sec shot, amp off.

And that's it. House it and give it a go. I use a Maplins MB1 box with a hole cut for the fan to push air out and I drill some holes over the ccd and a few holes in the ccd housing to allow air through.

An email I received from Martin about the latest QuickCam 4000 Pros:

Quote:

This is fresh from press as we've discovered it last week only.

There are now QC4000 out with a Vertical Driver named 3112SA instead of D1276AN (Sony CXD1267AN).

Snipped from my mail to another colleague:

----8<---------------------------------------------------------------------

This is a Panasonic MN3112SA and seems a replacement for the NEC16510.

Pinout is the same, so the Philips Mod type applies for this type and not longer the one for the QC3000

I.e. Pins VGate are 8 and 13 (SONY is 7 and 9) and Shutter is 10 (SONY is 4)

On the PCB the line to pin 10 is visible and could be cutted or pin lift,

Pins 8 and 13 seemed to be connected on the backside (one cannot see them on the chip side) - just below the CCD

so one has to lift the pins 8 AND 13 and connect them together via the bi-polar switches to the SAA chip directly (Pin 93 - take care to find the right one !!!). It has also a Sharp CCD and not a Sony one.

----8<---------------------------------------------------------------------

a) CCD Sony - Vertical Driver Sony CXD1267AN => similar to QC3000 Pro

b) CCD Sharp - Vertical Driver Sony CXD1267AN => Mod similar to QC3000 Pro (but different CCD brand)

c) CCD Sharp - Vertical Driver Panasonic MN3112SA (NEC pinout - beware don't apply a QC3000 Pro Mod)

Regards Martin

End Quote.

Identifying the CCD in a QuickCam 4000 Pro.

There's no easy way to tell which you have. If you can buy s/h that's more than a year old (i.e., off ebay) chances are you'll get one with the sony chip. I'm afraid that the sharp ccd cameras (IMHO) aren't worth bothering with - they are ~25lux compared to 1 lux or less for the sony chips.

I've recently adapted this mod for the toucam/ vesta. I'll post a short piece about doing this mod for the vesta, hopefully soon.

The ccd can be recognized one you've taken off the shell and the black cowl that covers it: