RF Biscuit Is A Versatile Filter Prototyping Board

As anyone who is a veteran of many RF projects will tell you, long component leads can be your undoing. Extra stray capacitances, inductances, and couplings can change the properties of your design to the point at which it becomes unfit for purpose, and something of a black art has evolved in the skill of reducing these effects.

RF Biscuit is [Georg Ottinger]’s attempt to simplify some of the challenges facing the RF hacker. It’s a small PCB with a set of footprints that can be used to make a wide range of surface-mount filters, attenuators, dummy loads, and other RF networks with a minimum of stray effects. Provision has been made for a screening can, and the board uses edge-launched SMA connectors. So far he’s demonstrated it with a bandpass filter and a dummy load, but he suggests it should also be suitable for amplifiers using RF gain blocks.

Best of all, the board is open source hardware, and as well as his project blog he’s made the KiCad files available on GitHub for everyone.

It’s a tough challenge, to produce a universal board for multiple projects with very demanding layout requirements such as those you’d find in the RF field. We’re anxious to see whether the results back up the promise, and whether the idea catches on.

This appears to be the first RF network prototyping board we’ve featured here at Hackaday. We’ve featured crystal filters before, and dummy loads though, but nothing that brings them all together. What would you build on your RF Biscuit?

Handy Power Supply with 3D Printed Case

You can never have too many power supplies around your workbench. It is easy to buy them or cobble something together for most purposes. But once in a while you see one that is simple and also looks good, like this one from [RegisHsu].

The project is simple since it uses off-the-shelf DC-to-DC converter modules, and good-looking LED meters to measure voltage and current. The dual supply can accept 5 to 16 V in (presumably from a wall transformer) and deliver 1.3 V to 15.5 V out at 2 amps. [RegisHsu] removed an adjustment pot from the converter board and replaced it with a 10-turn pot to allow voltage adjustment.

Given the parts, you probably don’t even need a wiring diagram. However, the part that brings it together is the 3D-printed case, which [RegisHsu] has on Thingiverse. We’ve looked at muti-turn pot replacements before, and this is hardly the first power supply project we’ve posted.

They Put the “P” in Power

Fuel cells are like batteries, sort of. Both use chemical reactions to produce electricity. The difference is that when a battery exhausts its reactants, it goes dead. In some cases, you can recharge it, but you typically get less energy back with each recharge. A fuel cell, on the other hand, will make electricity as long as you keep supplying fuel. What kind of fuel? Depends on the cell, but most often it is hydrogen or methanol.

Researchers at the University of Bath, Queen Mary University of London, and the Bristol Robotics Laboratory want to use a different fuel: urine. According to the researchers, that’s one resource we will never deplete. The fuel cell is a type of microbial fuel cell which is nothing new. The breakthrough is that the new cell is relatively inexpensive, using carbon cloth and titanium wire. Titanium isn’t usually something you think of as cheap, until you realize that conventional cells usually use platinum.

Continue reading “They Put the “P” in Power”

An Atari 2600 In Your Pocket

If there’s one console that holds a special place in the hearts of console gamers of a certain age, it’s the Atari 2600. A 6502 based system with a cartridge slot and a couple of joysticks, it plugged into your home TV and if you had one for Christmas in the late ’70s you were suddenly the coolest kid in the neighbourhood.

The last new 2600s were sold in the early 1990s, but all was not lost for 2600 fans. In the last decade the format was revived as the Atari Flashback, an all-in-one console containing a selection of games and no cartridge slot. The Flashback had a flaw though, it stayed true to the original in that it needed a TV set. Rather a pity in a world of hand-held consoles.

[Lovablechevy] set out to release the Flashback from the TV set, and created a very tidy hand held Atari 2600 console with sound and a screen, all in the casing of an original 2600 cartridge.

There isn’t a lot of room in a 2600 cartridge, so as her worklog shows, she had to cut up the PCB and be very careful with her wiring to ensure it all fits. She’s using the Flashback 2 as her source console, and she tells us it has 42 games to choose from.

If the worklog pictures weren’t enough she’s posted a video of the device in action, and it shows a very neat and playable hand-held console. We would have done anything to get our hands on one of those had it been available in 1980!

Continue reading “An Atari 2600 In Your Pocket”

Hacklet 101 – Pinball projects

There’s something about pinball that draws in hackers, makers, and engineers. Maybe it’s the flashing lights, the sounds, the complex mechanical movements. Could it be the subtle tactics required to master the game? Whatever the reason, everyone loves pinball, and more than a few hackers have dedicated their time and money toward building, restoring, and hacking pinball machines. This week’s Hacklet is all about the best pinball projects on Hackaday.io!

trekpinWe start with [zittware] and Star Trek: The Mirror Universe Pinball. [Zittware] worked with [clay], [fc2sw], and [steve] to create this awesome project. They took a 1978 Bally Star Trek pinball machine, and rebuilt an evil mirror universe version. The electronics include nixie tubes and a bulletproof power supply based upon an ATX computer setup. New play field elements and hardware were created on a CNC. Evil graphics were created with the help of Photoshop. The game is completely playable, and was a crowd favorite in the Hackaday Sci-Fi contest. The electronics and cabinet work are all open source. Unfortunately those pesky copyright laws prevent the team from sharing the artwork.

riiingpinNext up is [Erland Lewin] with RINNIG Pinball Simulator. Some hackers have the space for a few real pinball machines. For the rest of us, there is virtual pinball. [Erland Lewin] built this mini virtual pinball machine from plywood, some real pinball hardware, and a lot of ingenuity. The play field is a 24″ dell computer monitor, while the back glass is a 20″ monitor. A final 15″ monitor takes the place of the Dot Matrix Display (DMD) often found on pinball machines. The whole system is driven by an Intel i3 computer. [Erland] is going to try to use the on-board graphics. If he runs into trouble, he can always switch to a discrete graphics card. The machine has turned out great, and his sons love playing classic pinball machines on their own “kid sized” table.

pinboxIf virtual pinball is still a bit large for you, [Loyal J] has you covered with Pinbox Jr. Desktop computer virtual pinball has been a thing since the days of Windows XP. Somehow tapping keyboard keys isn’t quite the same as hitting real flipper buttons. Pinbox Jr. is a prototype pinball controller built inside a cardboard box. A Teensy 3.1 translates the buttons to USB keyboard inputs. Two large arcade buttons act as the flippers while two smaller buttons are available for game options and other functions.  [Loyal J] even added a triple axis accelerometer so pinbox responds to rough play with a tilt! All this project needs is a solenoid to replicate that real pinball feel.

optimusAt the top of the virtual pinball mountain stands [Randy Walker] with Optimus-Pin. Optimus is a full-sized virtual pinball cabinet. It’s a 3 screen affair, much like RINNIG Pinball up top. [Randy] took things to the next level with an absolutely gorgeous custom cabinet. The Transformers inspired artwork was created on commission by commercial artist [Javier Reyes]. Optimus really recreates the feel of playing pinball with 8 solenoids placed in strategic positions around the cabinet. Even the whirring of play-field motors is replicated by a hidden Volkswagen wiper motor. Optimus also comes with a complete light show including RGB LED strips, strobes, and a shaker to rattle the entire cabinet.

If you want to see more pinball projects check out our brand new pinball projects list! If I missed your project, don’t be shy! Just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Lighting Fires with Lemons

We all know that you can stick copper and zinc in an acid and make a battery. And the classic demonstration of this is with a lemon. YouTuber [NorthSurvival] takes this to an extreme — starting a fire by shorting his lemon battery across some steel wool. (Video embedded below.)

Now calling this a “survival tip” is pushing it. A lot. When’s the last time you went camping with a bunch of zinc and copper nails, much less a supply of fresh lemons? It might be easier to put some matches in a waterproof canister, or just bring a lighter. But when the zombie apocalypse comes, and all the lighters are used up, the man with a lemon tree will be a millionaire.

Seriously, though, this demo made us question a few assumptions. First, when people do the potato- or lemon-battery experiment, they often use multiple lemons. Why? Hooking the pins up like [NorthSurvival] did in series seems like a no-brainer after the fact.

And the lemon seems to be putting out a fair amount of juice (Amperes, that is). We’ve got to wonder — what is the short-circuit current of a lemon battery? And why haven’t we seen specs anywhere? What kind of “science education” experiment is this anyway, without measurements?

Continue reading “Lighting Fires with Lemons”

Extremely Thorough Formlabs Form 2 Teardown by Bunnie

[Bunnie Huang] recently had the opportunity to do a thorough teardown of the new Formlabs Form 2 printer. It’s a long read, so just head over there and immerse yourself in every detail. If you want the cliff notes, though, read this but still go look at all the pretty pictures.

First, it’s a major upgrade with pretty much every component. The CPU is a huge step up, the interface went from monochrome to full color touch screen, the connectivity has been upgraded with WiFi and Ethernet, the optics are much better and safer, the power supply is integrated, there are lots of little improvements that handle things like bed leveling, calibration, resin stirring, pausing jobs, and resin refilling during a print. Bunnie practically gushes at all the features and impressive engineering that went into the Form 2.

You can compare the teardown of the Form 2 to [Bunnie’s] teardown of the Form 1 printer back in 2013.