SPC900 LXmod yesyes style ;-)

[Reggie]

Just thought I'd post this for you all as we've been discussing USB and external power:

and the follow up video, looking at a better quality cheap chinese supply:

Makes for some very interesting viewing.

I do buy a few cheap chinese products myself, so I'm not showing this to knock anyone, I have one of the usb hubs that the first psu is supplied with, it turns out that the psu that comes with mine is the one in the 2nd video

There are lots of good quality products that are made in china for all the big manufacturers, so I don't see this as an issue with chinese products, just be aware that on the cheap stuff, you might just get what you pay for

[DIYASTRO]

Reggie and all:

Will try to begin some unified tests this weekend.

Just to report that I have changed the 4 way usb hub to the 7 way that Reggie indicated via ebay which arrived this morning.

Not been easy, but, have changed the hub and with the power adaptor the camera with YES YES mod (Serial to USB) and the GPUSB now all function very well.

The big test will be (for me) removing the power adapter and replacing with a 5v dc regulator circuit. Will use lm 317 circuit with resistor preset to get just over the 5 v. perhaps around 5. 2v. The LM 317T gives 1500mA which is enough for what I need and doesnt require too much extra components.

Will try and post some pics at the weekend. The bonus is that I now have 4 extra usb conections within the camera (all on skts with 1mm pitch) so that any extra utilities can be connected.

Boyd

[DIYASTRO]

Some Pics of latest YES YES mod with built in GPUSB.

With case removed

Top left; large green pcb is the 7 port usb hub the small pcb to the side of it is the usb to serial converter

Top right; side view, you can see the camera boards spc900nc with B&W icx098bl chip. The Yes Yes circuit board is the vero board.

Middle left; Is the base of the camera showing the GPUSB pcb and the connector (4pin) for the spc900 from the 7 way hub. Two extra 4 pin connectors and an 8pin connector are the remaining 4 usb (unused) hub connections.

Middle right; Rear of camera, showing 5v cooling fan switch for LX

external 5v dc plug for the extra power that was required. The rj45 skt for the gpusb which is basically the ST-4 guiding skt. The led is the indicator for the Shoestring GPUSB. ( more about this in future post!)

Bottom left; top/front view.

Now to build the 12-5 volt power supply so that I dont have to use the 5v mains adaptor which as Reggie posted (Youtube videos on Chinnese power supplies) are not up to the job anyway.

Boyd

[Reggie]

Boyd, did you check the 2nd video I posted a link to? It shows that not all cheap chinese PSU's are nasty, I know you want to power everything from DC sources but do yourself a favour and check the insides of the PSU that came with it, you might be pleasantly surprised like I was.

BTW. If your concerned about battery life then you might want to look at low dropout regulators instead of the lm317, lm317's are cheap but don't really care about the power they use, something like a micrel 29150 or 29300 would be a better bet, or one of the other MIC29XXX range:

MIC29150/29300/29500/29750 Series High-Current Low-Dropout Regulators

They're available on ebay or at farnell etc.

http://www.micrel.com/_PDF/mic29150.pdf

And I nearly forgot, your pics look fantastic, really impressed with your build, I get the feeling that when I eventually finish a mod it won't look anywhere near as professional as yours.

[yesyes]

Boyd, I have to agree with Reggie. That build looks absolutely impressive! ;-)

[DIYASTRO]

Thanks for kind comments guys!

Forgot to mention should anyone else intend to use a GPUSB. the USB connection lead that goes into the shoestring box is a cable and plug.

You can desolder the usb skt and it just so hapens that the pcb has a seperate row of solder pads which are even labeled for the colour of the wires to solder new conections to the hub. Very handy!

Will look into those voltage converters Reggie, unfortunate but my power supply that came with the hub is the same as the first video! Not good at all.

Boyd

[Reggie]

That's a real shame about the PSU.

[Davie]

Just ordering the bits and bobs for this (terrified as I'm a hammers and spanners man) but would like to ask if the cat5 cable I have a roll of in the loft is any use for the connections in this mod?

Silly questions like these will be popping up at intervals until i ether break it or get it working

Also does it matter if the resistors are carbon or metal film ?

Cheers

Davie

[Reggie]

The cat5 will probably be ok, although it might be a bit of a pain to strip without the right tools, best thing to do is try it, don't forget to get some flux (not the stuff pipe fitters use!!) and the resistors, Metal film 10k Ohm 0.25w will be fine

[Davie]

Cheers Reggie

I'm sure if I dig out my long lost cat5 crimping tool it's got a wire stripper on it (been a long time but I'm sure it has)

If not I've a sharp pair of snips and about 70m left to try and strip

[DIYASTRO]

Davie

I prefer to use striped cable from usb leads! They are small cross section stranded (easier to manipulate in tight spaces) and solder very well. The best leads for this are the type used for apple ipod etc, you also have the advantage of having the 4 main colours red black white and green. Other sources are 9 pin D pc cables although a little thicker gives you extra colours. Small 1mm tip soldering iron is helpfull especialy when soldering to base of transistor on camera board!

Boyd

[Gina]

I have used CAT5 strands of cable for wiring cct boards. You do need decent strippers to strip them though. In fact a good pair of strippers is so much better for stripping and cable. I use gash USB cables and other PC cables too. Yes, the fine stranded wire is just right for these "microscopic" jobs. I would also say a 1mm tip soldering iron is essential plus good solder (note, the "lead free" stuff often doesn't work very well, I prefer the lead alloy solder but take care not to breathe the smoke).

I have gone right down to wiring SMDs and use a single strand from stranded hook-up wire and a high power magnifier light plus "helping hands" to hold things while soldering. To get a good solder joint it's important to take the solder itself to the heated joint - don't take the solder to the joint on the soldering iron, it will have boiled off the flux.

[Reggie]

I have used the standard maplin single core wire for some projects but due to the surface mount parts on this mod I decided to use 'kynar' wire, single strand, very thin stuff, much easier to handle, here's a link to some stuff I got (they do multiple colours and do short lengths for just over a quid):

KYNAR WIRE 5M Blue - XBOX PS2 WII MODS 5 Metre 15 Feet | eBay

[yesyes]

I agree. While wires from Cat5 cables are good for other electronics projects, for this particular job they are probably too thick / stiff. You want the thinnest wire you can get. If a wire is too stiff, it can put too much force on solder pads and lift them when you move the wire (especially on the USB to serial converter PCB).

I've also used wires from old USB cables for most of these mods.

[Davie]

Thanks again for the answers.

Bought the wire Reggie recommended and I've used the ebay shop before so I know they are pretty quick.

[Reggie]

It sounds like you've probably already got some flux then davie? If not maplins do a very useful 'flux' pen or you can get a bottle of no-clean flux from ebay (mine is labelled no clean PS3 flux), both are relatively cheap.

I like the kynar wire, it seems very strong, I've been messing around on an old spc900nc with the LX circuit on a breadboard, it's hit the deck a couple of times and the whole circuit has survived without issue.

[Davie]

Again my lack of knowledge comes out the solder I have has flux through it if I remember but would have to go out to the garage to make sure.

Cant remember if it's lead alloy or not though and don't think it says on it

[Reggie]

I would still get some flux then just to be on the safe side, it's not going to hurt having extra that you can put exactly where you need it.

[datman]

OK, I've made some schematics of the whole thing (I hope malc-c doesn't mind that I have re-used parts of his diagram).

This shows how everything connects together. I hope that explains it a bit better. Any questions, just ask...

That is the simplest and clearest diagram I have seen for this mod. It makes it so obvious what needs to be done.

Brilliant!

[Davie]

Well the bits started to arrive today so began to do some soldering and hope over the next couple of nights (time allowing) I'll get this done

I'm sort of hoping to make an idiots idiot guide where numpties like me with absolutely no knowledge of electric trickery (Blue flashes and black magic I normally say) can get this done with more of a the blue wire goes here and the other end goes here approach but we will see what I can do.

Need to get this one working first

Be prepared for more daft questions over the next few nights!!

[Reggie]

Just remember to take your time, read everything at least twice and ask questions if you're unsure and you should get the mod done and keep the magic smoke in the electronics. Once you let the magic smoke out you can't put it back in!!

Make sure you've got some method for cleaning your soldering tip (damp sponge usually but not a plastic one, failing that, dampen an old rag and use that) and clean the tip as often as you need to. Dirty tip = not enough heat transfer to melt solder.

don't forget to tin your wires before you solder them to the board and don't be afraid of using flux to get things moving

[Gina]

If you don't know what "tin your wires" means... it's to heat the wire and apply solder to it before you try to make the joint.

[Davie]

A quick question for those brighter than the moss on rocks (I am that moss)

I'm using the logic chip method for doing this mod rather than the vero board way. Now I roughly followed a shopping list somewhere in the depths of the forums and the switch listed was this Sub-Min Toggle E FH04E (maplins description and part number)

Now to a numptie like me this has 6 lugs to solder the wires onto but to me a switch should either be circuit open or closed. Does anybody know where to solder on the 5v, and the others from pad and pin 7, or do I need a totally different switch?

Also I've seen a difference of opinion (remember Winner takes all?) on whether it should be 10k or a 100k resistor on the 5v line to the switch.

again thanks for the help and will hopefully have a colour coded guide for those hard of thinking like myself soon.

[Davie]

Had a quick rake around and when looking at Geppettos thread I see that a similar switch is used so I think (been wrong more than once so always ready to be wrong again ... and again ) that the 5v with a 100k resistor along with the wire from pad 7 go to one of the outside lugs on the switch and the wire from pin 7 goes to the middle of the three lugs.

I know it's bad to assume but as its an on-on switch I take it it doesn't matter which of the outside lugs on of the switch is used?

thanks again

Davie

[NEM]

The switch you have is a double pole double throw (DPDT) one. Each group of three terminals is a changeover switch where toggling the switch changes the connection between a centre terminal and the ones on either side of it. So to use it in your circuit, just connect to one of the centre terminals and either one of the terminals on the same group of three.

Regarding the resistor value, I'd need to see the diagram, but since these are digital circuits, the resistor values usually aren't critical.

Regards,

Noel