[quote author="tayken"]I ordered some from Deal Extreme. It dried up quickly but was really good at first. Nothing that some IPA and liquid flux cannot solve.[/quote]
Did you succeed reviving it? I have tried fixing my Deal Extreme paste with both IPA and very fluid BGA flux but it ended up being unusable. It was really hard to gen the consistency right and when I tried reflowing it in my oven it just sputtered and exploded into small pieces. Maybe a proper preheat profile would have solved this, but I usually can do without a proper profile with fresh solder paste.
I'm trying to get the open source usb stack running on my board with a PIC18F25J50 but having a hard time getting it working. I've added ifdef's in the code for the processor so it compiles just fine but I think I screwed up the linker script since my board just gives an "Usb device not recognized "-error when I connect it.
Being a Atmel guy for the last decade or so I'm not up to speed with the pic specifics in the linker files. So if anyone could help me out here it would be great...
The tracks on the board are about 5 mm wide and those short runs in open air would be able to handle 12-15 amps without going more than 30 degrees C above ambient. A bit hot yes, but not too bad.
According to Daves experiments on his blog this could be increased to considerably more (double?) by removing the soldermask over the tracks and put a good helping of solder on top of the tracks.
Still, most people only need an amp or two so the PCB fulfills that need. For larger currents cheap banana plugs and the most likely thin wiring is not suitable anyways. For really large currents a proper PSU should have sense-wires that will compensate for the voltage losses in the cables and contacts - something that the PC PSUs are sadly lacking.
Hi Francisco, sorry about that. It seems like I screwed up the forwarding of the mail address to my regular mail account so your mail was waiting for me in the pcbswap -mail account. I'll get back to you that offered to help out in a day or two.
I'm having a really hard time deciding what I think about this kit.
On one hand it is very nice and convenient to get all the common jellybean parts (and some not so jellybean) in one go. Someone has already selected the parts for me and searched for good prices at a reputable distributor.
But on the other hand I'm a person who often get a buttload of the same part when I purchase something that is reasonably cheap anyways. Like I can get 100 SMD Mini-USB connectors for $9.99 free shipping at ebay, or 200 of the 2.1mm SMD powerjacks for $49 shipped - that's 1/6th of the 10-quantity price at Mouser.
I'd probably go for this kit if I was just starting doing SMD stuff and was reasonably experienced in thru-hole electronics. And as said by someone else the 0603 might be a bit scary for beginners - I use 0805 since I'm approaching 50 and my eyesight is not what it used to be. But since DP is a 0603-company it makes sense to have the kit in 0603 as well.
<sarkasm> I must have a LOUSY DESIGNED house. ^_^ The mains wiring into my house can probably support 100+ amps but still the fuses in my power distribution central is only fused with wimpy 10 amp fuses on the circuits. I must hurry down and replace them with more beefy fuses so I can power my linear accelerator ring the day I finish it.... </sarkasm>
Why not just replace the polyfuses with a piece of wire if you want to max the PSU out? The PSU got internal protections over- or under-current. But is there really a need to use the ATX breakout at all in a fixed installation like this? Just cut off the connector and solder on new wires either directly into the PSU PCB or onto the already existing wires.
The boards seems quite neat for SMD prototyping where you can solder the parts directly onto the pads and then easily can bridge the pads to neighboring pads. If they work as advertised they might the the biggest evolution in protoboard-technology in many years.
Not bad.... Not too expensive and can be made really small - sometimes an extra microcontroller makes sense.
I just routed a small PCB for the Roman Black version with the addition of being able to read a button as well from the same single port. It works like a charm on the breadboard and I can fit three of them on a 5x5cm Seeed PCB, so I think I'll make a batch of them just for fun.
Are you sure you need a business visa? If your're not doing actual business or making contacts with the PCB houses for business purposes I would imagine that a standard tourist visa or possibly an "Entry" visa (given to people whose purpose doesn't fit squarely into any other category) would suffice.
If I would go I wouldn't do any business related things there, just visiting things that interest me more than pagodas and beaches - namely electronics and technical stuff.
I've been thinking along the same lines for a while too, but I took a slightly different tangent.
Why have Ian pay for the postage and other fulfillment costs? I think that it would be fairer to have a peer-to-peer model of the free PCBs instead.
I'm almost ready to open up the http://http://www.pcbswap.com/ website - a day or two more should be enough for a first release of it. The PcbSwap.com is for us who order PCBs from Seeed or Itead and have a lot of extras and want to swap some of them for other PCBs at 0-cost. Each sender pays for the shipping themselves.
I could use someone to help me debug and test the site before opening it.... Any takers?
That's an interesting alternative to the common '595 three-wire interface to LCD's - I don't remember that I've seen it before.
Another version that not all might be aware of is a 1-wire interface using RC timing and a '595. Very slow but only uses one pin on the microcontroller so it might come in handy sometimes.
I decided that it was time to solder up the POVtoy PCB that I got as a free PCB a while back.
To my surprise I discovered that I was all out of some more or less common parts in my component boxes. Things like 18pf caps and 20 MHz crystals and even 3.3v LDO regs was "out of stock" in my collection, but I really wanted to finalize the project once I had started so I replaced them with standard PTH parts without too much trouble.
I also always use 0805 parts and not the 0603 that the POV Toy BOM specifies, but the 0805's fit just fine on the board so no problem there. I must admin that I've never used resistor nets (that the POV Toy uses) so I just replaced them with ordinary discrete 0805's and soldered them standing on edge instead of the normal flat orientation - it was not too hard to get them in place.
Now it's time to flash some FW into it and see if it's alive...
As Jeff Epler and some others guessed it it a KIM-1 emulator.
The KIM-1 is a 6502 single board development board dating back to 1977. Having 1 KB RAM running on 1 MHz it's not a speed demon, but it was my first computer back then that I spent countless hours on writing assembly mnemonics on paper and translating it by hand into hex codes entering it into the computer using the hex keypad and pressing go to execute it. Fun times back then when I was 12 years old.
I still have the it in my lab, but unfortunately I've repurposed the 6502 and a couple of displays many years ago so I can't use it. Maybe it's time to restore it to it's former glory....
If anyone would like to help out with the project and have access to a PDI capable programmer, like a AVR Dragon, I'd be happy to send a PCB and the hard-to-get displays to you, but you need to supply the other parts and solder it up yourself.
