Author: Bryan Cockfield

1851 Articles

Guitar Effects With No (Unwanted) Delay

March 15, 2021 by 23 Comments

MIDI has been a great tool for musicians and artists since its invention in the 1980s. It allows a standard way to interface musical instruments to computers for easy recording, editing, and production of music. It does have a few weaknesses though, namely that without some specialized equipment the latency of the signals through the various connected devices can easily get too high to be useful in live performances. It’s not an impossible problem to surmount with the right equipment, as illustrated by [Philip Karlsson Gisslow].

The low-latency MIDI interface that he created is built around a Raspberry Pi Pico. It runs a custom library created by [Philip] called MiGiC which specifically built as a MIDI to Guitar interface. The entire setup consists of a preamp to boost the guitar’s signal up to 3.3V where it is then fed to the Pi. This is where the MIDI sampling is done. From there it sends the information to a PC which is able to play the sound back quickly with no noticeable delay.

[Philip] also had to do a lot of extra work to port the software to the Pi which lacks a lot of the features of its original intended hardware on a Mac or Windows machine, and the results are impressive, especially at the end of the video where he uses the interface to play a drum machine via his guitar. And, while MIDI is certainly a powerful application for a guitarist, we have also seen the Pi put to other uses in this musical realm as well.

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Custom Dummy Load With Data Logging

March 15, 2021 by 10 Comments

While it might seem counterintuitive on the surface, there are a number of cases where dumping a large amount of energy into a resistor simply to turn it into heat is necessary to the operation of a circuit. Most of these cases involve testing electronic equipment such as power supplies or radio transmitters and while a simple resistor bank can be used in some situations, this active dummy load is comprised of different internals has some extra features to boot.

The load bank built by [Debraj] is actually an electronic load, which opens it up for a wider set of use cases than a simple passive dummy load like a resistor bank. It’s specifically designed for DC and also includes voltage measurement, current control, and temperature measurement and speed control of the fans on the heat sinks. It also includes a Bluetooth module that allows it to communicate to a computer using python via a custom protocol and GUI.

While this one does use a case and some other parts from another product and was specifically built to use them, the PCB schematics and code are all available to build your own or expand on this design. It’s intended for DC applications, but there are other dummy loads available for things such radio antenna design, and it turns out that you can learn a lot from them too.

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Your Plants Can Take Care Of Themselves Now

March 14, 2021 by 41 Comments

One of [Sasa]’s life goals is to be able to sit back in his home and watch as robots perform all of his work for him. In order to work towards this goal, he has decided to start with some home automation which will take care of all of his house plants for him. This project is built from the ground up, too, and is the first part of a series of videos which will outline the construction of a complete, open-source plant care machine.

The first video starts with the sensors for the plants. [Sasa] decided to go with a completely custom module based on the STM32 microcontroller since commercial offerings had poor communications designs and other flaws. The small board is designed to be placed in the soil, and has sensors for soil moisture as well as other sensors for amount of light available and the ambient temperature. The improvements over the commercial modules include communication over I2C, allowing a large number of modules to communicate over a minimum of wires and be arranged in any way needed.

For this build everything is open-source and available on [Sasa]’s GitHub page, including PCB layouts and code for the microcontrollers. We’re looking forward to the rest of the videos where he plans to lay out the central unit for handling all of these sensors, and a custom dashboard for controlling them as well. Perhaps there will also be an option for adding a way to physically listen to the plants communicate their needs as well.

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Motorcycle Needs Custom Latching Switches For Turn Signals

March 13, 2021 by 42 Comments

While modern cars have been getting all kinds of fancy features like touch screens, Bluetooth, crumple zones, and steering wheel controls, plenty of motorcycles have remained firmly in the past. Some might have extra options like a fuel gauge or even ABS if you’re willing to spend extra, but a good percentage of them have the bare minimum equipment required by law. That equipment is outdated and ripe for some improvements too, like this ergonomic custom turn signal switch built with custom latching switches.

Since motorcycle turn signals don’t self-cancel like car signals the rider has to cancel it themselves, usually by pushing an inconveniently tiny button. This assembly consists of four separate switches, two of which control the left and right turn signals. Since both can’t be on at the same time, they include circuitry that can detect their position and a small motor that can physically de-latch them if the other one is pressed. The entire assembly is 3D printed, including the latching mechanism, and they are tied together with a small microcontroller for the controls.

The truly impressive part of this build is the miniaturization, since all four buttons have to be reached with the thumb without removing the hand from the handlebar. The tiny circuitry and mechanical cam for latching are impressive and worth watching the video for. And, if you need more ergonomic improvements for your motorcycle there are also some options for cruise control as well, another feature often lacking in motorcycles.

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Battery Of The Future, Now Buildable Yourself

March 13, 2021 by 9 Comments

In theory, batteries and capacitors are fairly simple. One stores energy chemically and the other stores energy in an electric field. In practice though, building an energy storage device that has a practical amount of energy density is delicate, complex work. But if you have access to a few chemical compounds it’s actually not too difficult to produce useful batteries and electrolytic capacitors with the use of ionic liquids.

Ionic liquids are conductive liquids with a few other important qualities. Almost all of the ones shown can be built with relatively common compounds, and most of the products have advantageous physical qualities, making them stable and relatively safe for use. With some equipment found in a chemistry lab it’s possible to produce a wide variety of these liquids without too much hassle (although one method outlined uses an inert gas chamber), and from there batteries and capacitors can be built by allowing the ionic liquids to be absorbed into the device.

The video below shows the production of several of these devices and then illustrates their effects by running a small LED light. While they’re probably not going to be used to create DIY electric cars anytime soon, the production and improvement of atypical energy storage devices will be the key to a large part of the energy needs of society now and into the future, especially aluminum batteries like these.

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DIY Telescope Courtesy Of IKEA

March 12, 2021 by 39 Comments

Some of the most expensive hobbies have some of the more ingenious hacks on display, generally to lower the cost of entry to various parts the hobby itself. Amateur astronomy has expensive, necessary equipment such as telescopes and other optics, but also has a large group of people willing to build their own gear out of some surprising materials rather than buy pre-built equipment.

One of the latest telescopes from [The Amateur Engineer] uses several bowls from IKEA to build the mirror mount. It’s a variation of a Portaball telescope, which is similar to a Dobsonian telescope except that it is much easier to adjust and point in any direction. This “Portabowl” telescope uses two bowls epoxied together and weighted at the bottom as the core of the build. The mirror mounts inside the ball, and some supports are attached to it to hold the eyepiece and mount. With some paint and some minor adjustments it’s ready to go stargazing.

There are a few improvements to this build planned for the future, such as the creation of a larger ball that will make operating the scope easier. All in all, though, it’s an excellent example of amateur astronomy even without needing to go as far as grinding one’s own mirrors.

Growing The World’s Largest Snowflake

March 12, 2021 by 7 Comments

Plenty of areas around the world don’t get any snowfall, so if you live in one of these places you’ll need to travel to experience the true joy of winter. If you’re not willing to travel, though, you could make some similar ice crystals yourself instead. While this build from [Brian] aka [AlphaPhoenix] doesn’t generate a flurry of small ice crystals, it does generate a single enormous one in a very specific way.

The ice that [Brian] is growing is created in a pressure chamber that has been set up specifically for this hexagonal crystal. Unlike common ice that is made up of randomly arranged and varying crystals frozen together, this enormous block of ice is actually one single crystal. When the air is pumped out of the pressure chamber, the only thing left in the vessel is the seed crystal and water vapor. A custom peltier cooler inside with an attached heat sink serves a double purpose, both to keep the ice crystal cold (and growing) and to heat up a small pool of water at the bottom of the vessel to increase the amount of water vapor in the chamber, which will eventually be deposited onto the crystal in the specific hexagonal shape.

The build is interesting to watch, and since the ice crystal growth had to be filmed inside of a freezer there’s perhaps a second hack here which involved getting the camera gear set up in that unusual environment. Either way, the giant snowball of an ice crystal eventually came out of the freezer after many tries, and isn’t the first time we’ve seen interesting applications for custom peltier coolers, either.

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