# Relay Computer: You Can Hear It Think

Modern digital computers have complex instruction sets that runs on state-of-the-art ALUs which in turn are a consequence of miniaturized logic gates that are built with tiny transistors. These tiny transistors are essentially switches. You could imagine replacing with electromagnetic relays, and get what is called a relay computer. If you can imagine it, someone’s done it. In this case, [jhallenworld].

The Z3 was the first working programmable, fully automatic digital computer designed by Konrad Zuse. The board employs modern semiconductor devices such as memory and microcontrollers, however, the CPU is all relays. A hexadecimal keyboard allows for program entry and a segment display allows tracking the address and data. The program is piped into serial to the parallel decoder and fed to the CPU where the magic happens. Since the core is electromechanical it is possible to connect the output to peripherals such as a bell as demonstrated near the end of the video.

This project is a good balance of retro and modern to be useful to anyone interested in mechanical computers and should be a lot of fun for the geek kind. Hacking this computer to modify the instruction set should be equally rewarding and a good exercise for students of computing theory.

There is a SourceForge page dedicated to the project with the details on the project including the instruction set and architecture. Check out the video below and if you are inspired by the project, be sure to check out the [Clickity Clack]’a Videos on designing a relay computer bit by bit.

# Antenna Basics By Whiteboard

Like a lot of people, [Bruce] likes radio controlled (RC) vehicles. In fact, many people get started in electronics motivated by their interest in RC. Maybe that’s why [Bruce] did a video about antenna basics where he spends a little more than a half hour discussing antennas. You can see the video below.

[Bruce] avoids any complex math and focuses more on intuition about antennas, which we like. Why does it matter that antennas are cut to a certain length? [Bruce] explains it using a swing and a grandfather clock as an analogy. Why do some antennas have gain? Why is polarization important? [Bruce] covers all of this and more. There’s even a simple experiment you can do with a meter and a magnet that he demonstrates.

# Open Source High Power EV Motor Controller

For anyone with interest in electric vehicles, especially drives and control systems for EV’s, the Endless-Sphere forum is the place to frequent. It’s full of some amazing projects covering electric skateboards to cars and everything in between. [Marcos Chaparro] recently posted details of his controller project — the VESC-controller, an open source controller capable of driving motors up to 200 hp.

[Marcos]’s controller is a fork of the VESC by [Benjamin Vedder] who has an almost cult following among the forum for “creating something that all DIY electric skateboard builders have been longing for, an open source, highly programmable, high voltage, reliable speed controller to use in DIY eboard projects”. We’ve covered several VESC projects here at Hackaday.

While [Vedder]’s controller is aimed at low power applications such as skate board motors, [Marcos]’s version amps it up several notches. It uses 600 V 600 A IGBT modules and 460 A current sensors capable of powering BLDC motors up to 150 kW. Since the control logic is seperated from the gate drivers and IGBT’s, it’s possible to adapt it for high power applications. All design files are available on the Github repository. The feature list of this amazing build is so long, it’s best to head over to the forum to check out the nitty-gritty details. And [Marcos] is already thinking about removing all the analog sensing in favour of using voltage and current sensors with digital outputs for the next revision. He reckons using a FPGA plus flash memory can replace a big chunk of the analog parts from the bill of materials. This would eliminate tolerance, drift and noise issues associated with the analog parts.

[Marcos] is also working on refining a reference design for a power interface board that includes gate drivers, power mosfets, DC link and differential voltage/current sensing. Design files for this interface board are available from his GitHub repo too. According to [Marcos], with better sensors and a beefier power stage, the same control board should work for motors in excess of 500 hp. Check out the video after the break showing the VESC-controller being put through its paces for an initial trial.

# Synthesizing Daraprim To Beat Price Gougers

Drugs are used the world over to treat disease. However, from time to time, the vagaries of market economics, or unscrupulous action, can radically increase the price of otherwise cheap pharmaceuticals far beyond the reach of the average person. This was the case with Pyrimethamine (sold as Daraprim), which is used to treat toxoplasmosis and malaria, among other users. With the price skyrocketing from \$13 to \$750 a tablet in the US in 2015, [NurdRage] decided to synthesize the drug on their own. (If you missed the background hubbub, search for “Martin Shkreli”.)

The video linked covers the final synthesis, though [NurdRage] has previously covered the synthesis of the required precursor chemicals. Budding chemists may grow excited, but there are significant hurdles to attempting this synthesis yourself. Chemicals involved are carcinogenic, toxic, acidic, or otherwise dangerous, and a fume hood is a necessity if working inside. Outside of this, there are immense risks in homebrewing pharmaceuticals. Performing the synthesis of an important drug is one thing, but to do so at a medical-grade level where the products are safe for human consumption is on an entirely different level.

Overall, [NurdRage] has put out a series of videos that have strong educational value, showing us what really goes into the production of a common pharmaceutical compound. There’s also something to be said about taking the production of life-saving medicines into one’s own hands in the face of prohibitive treatment costs. In a similar vein, perhaps you’ve considered producing your own insulin in an emergency?

[Thanks to jwrm22 for the tip]

# The Things Network Sets 702 Km Distance Record For LoRaWAN

Many of us will have at some time over the last couple of years bought a LoRaWAN module or two to evaluate the low power freely accessible wireless networking technology. Some have produced exciting and innovative projects using them while maybe the rest of us still have them on our benches as reminders of projects half-completed.

If your LoRaWAN deployment made it on-air, you’ll be familiar with the range that can be expected. A mile or two with little omnidirectional antennas if you are lucky. A few more miles if you reach for something with a bit of directionality. Add some elevation, and range increases.

A couple of weeks ago at an alternative society festival in the Netherlands, a balloon was launched with a LoRaWAN payload on board that was later found to have made what is believed to be a new distance record for successful reception of a LoRaWAN packet. While the balloon was at an altitude of 38.772 km (about 127204.7 feet) somewhere close to the border between Germany and the Netherlands, it was spotted by a The Things Network node in Wroclaw, Poland, at a distance of 702.676km, or about 436 miles. The Things Network is an open source, community driven effort that has built a worldwide LoRaWAN network.

Of course, a free-space distance record for a balloon near the edge of space might sound very cool and all that, but it’s not going to be of much relevance when you are wrestling with the challenge of getting sensor data through suburbia. But it does provide an interesting demonstration of the capabilities of LoRaWAN over some other similar technologies, if a 25mW (14dBm) transmitter can successfully send a packet over that distance then perhaps it might be your best choice in the urban jungle.

If you’re curious about LoRaWAN, you might want to start closer to home and sniff for local activity.

# The Components Are INSIDE The Circuit Board

Through-hole assembly means bending leads on components and putting the leads through holes in the circuit board, then soldering them in place, and trimming the wires. That took up too much space and assembly time and labor, so the next step was surface mount, in which components are placed on top of the circuit board and then solder paste melts and solders the parts together. This made assembly much faster and cheaper and smaller.

Now we have embedded components, where in order to save even more, the components are embedded inside the circuit board itself. While this is not yet a technology that is available (or probably even desirable) for the Hackaday community, reading about it made my “holy cow!” hairs tingle, so here’s more on a new technology that has recently reached an availability level that more and more companies are finding acceptable, and a bit on some usable design techniques for saving space and components.

# These Twenty Assistive Technologies Projects Won \$1000 In The Hackaday Prize

Today, we’re excited to announce the winners of the Assistive Technologies portion of The Hackaday Prize. In this round, we’re looking for projects that will help ensure a better quality of life for the disabled. Whether this is something that enhances learning, working, or daily living. These are the projects that turn ‘disability’ into ‘this ability’.

Hackaday is currently hosting the greatest hardware competition on Earth. We’re giving away hundreds of thousands of dollars to hardware creators to build the next great thing. Last week, we wrapped up the fourth of five challenges. It was all about showing a design to Build Something That Matters. Hundreds entered and began their quest to build a device to change the world.

There’s still one entry challenge remaining in The Hackaday Prize. Anything Goes is on right now and open to every idea imaginable. If you’re building a computer made of sand, awesome. Quadcopter hammock? Neat. This is the portion of the Hackaday Prize that’s open to the best ideas out there. It’s up to you to explain how your creation makes the world a little bit better place.

The winners of the Assistive Technologies challenge are, in no particular order: