Field programmable gate arrays, or FPGAs are wonderful little devices. In a nutshell, they are a whole load of logic blocks, wired together with interconnects. These logic blocks can be wired up however you like, to create simple, or complicated circuits. Anything from a simple XOR gate, to a CPU, to an entire system (if you have enough money to buy the biggest ones). Think of them as a big box of lego bricks that you can combine in any way you want to create any kind of digital circuit.
FPGAs have been used in many applications – emulation of older systems being one. The MiSTer is one such example. Jeri Ellsworth’s C-One is another. But really, FPGAs are found everywhere. They are quick, robust and adaptable to most situations.
My friend Will runs the Project-F website where he investigates all things FPGA. I’ve been helping out by building some boards for us, and this is one of the first. I’d like to show you all how I went about building one of our early prototypes, the triumphs and pitfalls and hopefully inspire folks to give it a go themselves.
A highlight of last year’s Hackaday Remoticon was a soldering competition that had teams from around the world came together online and did the well-known MakersBox SMD Challenge kit in which a series of LED circuits of decreasing size must be soldered. The Hackaday crew acquitted themselves well, and though an 01005 resistor and LED certainly pushes a writer’s soldering skills to the limit it’s very satisfying to see it working. Lest that kit become too easy, [Arthur Benemann] has come up with something even more fiendish; his uSMD is a 555 LED flasher that uses a BGA 555 and a selection of 008004 small components.
The trick with an 01005 is to heat not the tinned and fluxed solder joint, but the trace leading up to it. If components of that size can be mastered then perhaps an 008004 isn’t that much smaller so maybe the same technique might work for them too. In his tip email to us he wrote “Soldering 008004 isn’t much worse than a 0201, you just need magnification“, and while we think he might be trolling us slightly we can see there’s no reason why it shouldn’t be do-able. Sadly he doesn’t seem to have made it available for us to buy and try so if you want to prove yourself with a soldering iron you’ll have to source the PCBs and parts yourself. Still, we suspect that if you are the type of person who can solder an 008004 then that will hardly be an onerous task for you.
When you’re just learning to sketch, you use graphite. Why? It’s cheap, great at training you to recognize different shades, and most of all, it’s erasable. When you’re learning, you’re going to make mistakes, and un-making them is an important part of the game. Same goes for electronics, of course, so when you’re teaching someone to solder, don’t neglect teaching them to desolder
We could argue all day about the best ways of pressing the molten-metal undo button, but the truth is that it’s horses for courses. I’ve had really good luck with solder braid and maybe a little heat gun to pull up reluctant SOIC surface-mount chips, but nothing beats a solder sucker for clearing out a few through-holes. (I haven’t tried the questionable, but time-tested practice of blasting the joint with compressed air.)
For bulk part removal, all you really have to do is heat the board up, and there’s plenty of ways to do that, ranging from fancy to foolish. Low-temperature alloys help out in really tough cases. And for removing rows of pinheaders, it can help to add more solder along the row until it’s one molten blob, and then tap the PCB and watch the part — and hot liquid metal! — just drop out.
The inspiration for this one comes from the [Hand Tool Rescue] video that shows of the clever mechanism. The vice uses a series of interlocking parts that can freely articulate to grip the object of interest via several protruding fingers. In reproducing the design, [Chris] had some issues initially with the joints, but settling on a dovetail similar to that of the original metal vice which got things working nicely.
If you want to build cool things these days, you’ve probably had to master surface mount electronics. However, for many people, ball grid array (BGA) is still intimidating. Have a look at [VoltLog’s] video about his techniques for soldering BGA and inspecting that you managed to do it right.
He’s got quite a few tips about things like surface finish and flux selection. It looks easy when he does it. Of course, having a good PCB with good registration markings will help too.
You can’t get a soldering iron under the part, of course. A hot plate provides heat from underneath. A gentle push from a hot air gun will push the solder balls over the melting edge. Even taking the part off the hotplate requires a special technique.
Without seeing the result, how can you know if it was successful? Pros can use an X-ray machine, but you probably don’t have one of those sitting in your shop. [VoltLog] uses a DVM and tests the internal protection diodes that the chip almost certainly has on its pins. However, to do that, you need to put the chip on a bare board. If you were repairing an existing board, the technique wouldn’t be useful since other components on the board would throw the measurements off.
Oregon State University must be a pretty good place to go to school if you want to hack on robots. Their robotics club, which looks active and impressive, has a multi-part video series on how to solder surface mount components that is worth watching. [Anthony] is the team lead for their Mars Rover team and he does the job with some pretty standard-looking tools.
The soldering station in use is a sub-$100 Aoyue with both a regular iron and hot air. There’s also a cheap USB microscope that looks like it has a screen, but is covered in blue tape to hold it to an optical microscope. So no exotic tools that you’d need a university affiliation to match.
Even if you’ve done a lot of SMD soldering, you can always pick up new tips and tricks. There’s lots of flux, of course, and careful alignment before you secure the component down. We know the feeling of leaving a bad solder joint long enough to go secure the other pads and then cleaning it up at the end.
The perfect night-light, and a great way to learn how to solder.
The Joule Thief is a clever little circuit that can light a LED with a battery that is nearly dead. It does this with a pair of opposing magnetic fields. I like this circuit because it is simple to build, yet demonstrates some very complex electrical behavior.
I’ve designed a printed circuit board to help make this easier to build for beginning Makers. I used open source KiCAD software to lay it out (a future Instructable?), and OSHPark to manufacture it. If you want to just wire one up without the board, check out Angelo’s Instructable which uses essentially the same circuit.
Soldering irons are a personal tool. Some folks need them on the cool side, and some like it hot. Getting it right takes some practice and experience, but when you find a tip and temp that works, you stick with it. [Riccardo Pittini] landed somewhere in the middle with his open-source soldering station, Soldering RT1. When you start it up, it asks what temperature you want, and it heats up. Easy-peasy. When you are ready to get fancy, you can plug in a second iron, run off a car battery, record preset temperatures, limit your duty-cycle, and open a serial connection.
The controller has an Arduino bootloader on a 32u4 processor, so it looks like a ProMicro to your computer. The system works with the RT series of Weller tips, which have a comprehensive lineup. [Riccardo] also recreated SMD tweezers, and you can find everything at his Tindie store.
Soldering has a way of bringing out opinions from novices to masters. If we could interview our younger selves, we’d have a few nuggets of wisdom for those know-it-alls. If ergonomics are your priority, check out TS100 3D-printed cases, which is an excellent iron, in our opinion.