Evan’s DIY OpenDPS power supply: Years ago I heard about the OpenDPS project to give open source firmware to cheap and available chinese power supplies. These aren’t strictly whole power supplies, they are configurable CC and CV buck converters. That means that it needs a stable DC source to back it to be used as […]
Category Archives: DIY
How to make a very cheap VHF receiver
Sverre’s cheap VHF receiver: What is the cheapest receiver you can make for VHF? Here is a candidate where all you need to do to modify a small FM headphone receiver is to desolder one end of two capacitors, and connect a short cable with an antenna connector. See the full post on LA3ZA Radio […]
(Not a) triple tube geiger counter
Doz’ triple tube geiger counter project, that is available on GitHub: So, two little switching power supplies, one for the DOB-50 and CTC-5 as they have similar operating voltages, and one higher voltage one for the DOB-80, a simple op-amp comparator to output the pulses to an Arduino to process and display the results. The […]
The Hayes Chronograph, a remake for 2020
smbakeryt built his own Hayes Chronograph: I’ve always wanted a Hayes Chronograph, but have never been able to acquire one, so I finally broke down and just made my own. The Hayes Chronograph was a compliment to Hayes line of smart modems, and implemented a real time clock for computers that didn’t have a built-in […]
100 MHz third overtone crystal oscillator
100 MHz third overtone crystal oscillator @ DIYfan: Couple of years ago I purchased from a local store 100 MHz crystal resonator and tried several times to make a working schematic on breadboard using standard circuits I found on the internet. It never worked good enough, usually oscillating at 33.3 MHz instead of 100 MHz. […]
DIY MechBoard64
DIY MechBoard64 @ breadbox64.com: When the MechBoard64 was finally realized and presented on my blog, it soon came clear that a new mechanical keyboard was the missing piece in the creation of a brand new Commodore 64 (…well that and some new keycaps…). As I have no intention to become a Commodore 64 mechanical keyboard […]
Shirt-pocket SSB transceiver
Peter (DK7IH) blogged about his 14MHz shirt-pocket SSB transceiver.
Low cost Carbon Monoxide meter
Dilshan has published a new build: Today Carbon Monoxide (CO) meters are available in different forms. Overall, Carbon Monoxide meters sense CO fast and display the amount to the user and trigger alarm if it reaches a critical level. Compare with most of the DIY Carbon Monoxide meters, the project which we described in this […]
Measure voltage and current with the Tiny V/A Meter
Here’s KarlTorp’s palm-sized Tiny V/A: Tired of replugging your multimeter when you want to measure both voltage and current on a small project? Tiny V/A meter is the device you need! Via Arduino Blog. Check out the video after the break.
CyberDeck ZBS
Recycled cyberdeck made from old project Raspberry pi Zero Boot System @ Facelesstech: So when I redesigned my ZBS (zero boot system) I decided to also make a thinner version of my portable raspberry pi setup. This worked out great and I used it to develop the raspberry pi add-ons and the software for the […]
DIY ARC reactor CPU performance monitor, powered by an Arduino
Michael @ the-diy-life.com posted detailed instructions of how to build your own Arc reactor CPU performance monitor: In this project, I’m going to be showing you how to turn one of these popular DIY arc reactor kits into a useful Arc Reactor CPU performance monitor for your computer. It plugs into one of your computers […]
cVert, a truly random MIDI controller
cVert, a truly random MIDI controller @ danny.makesthings.work cVert is the result of an idea I’ve been kicking around for years, and took a few months of work to bring to fruition. The idea was to use a Geiger counter as a true random number generator to give a non-deterministic input for computer art or […]
DIY home made portable oscilloscope
An ATmega328 based portable home made oscilloscope with ADC from Creative Engineering: It is basically a small scaled digital oscilloscope. It is capable of displaying all type of waveform like sine, triangular, square, etc. It’s bandwidth is above 1 MHz and input impedance is about 600K. The device is mainly using the ATmega328 micro-controller as […]
Building an ATmega 1284p based data logger
A detailed instructions of how to build an ATmega 1284p based data logger: In this tutorial, a logger is built using a 3.3v Moteino MEGA with a 1284p CPU @ 16Mhz, w 4K eeprom,16K SRAM for variables & 128K program space. Considerably more than the 328’s 1K eeprom, 2K ram & 32K progmem. Also has […]
Hotkey keypad from cash register
Fwacer shared detailed instructions of how to build this shortcut keyboard from an old cash register, project instructables here. More details at brycedombrowski.com.
DIY Arduino RC receiver for RC models and Arduino projects
Dejan @ howtomechatronics.com shows how to make an Arduino based RC receiver: Now these two devices can easily communicate and we can use them for controlling many things wirelessly. I will explain how everything works through few examples. In the first example we will use this Arduino RC receiver to control a simple car consisting […]
Experimental motor driver for CG-4 German equatorial mounts
Dilshan has published a new build: This is an experimental stepper motor driver for Celestron CG-4 German equatorial mounts. This unit is functionally equivalent to the Celestron dual-axis motor driver, and we developed it as a replacement unit for the original Celestron driver. See the full post on Dilshan Jayakody’s blog. Project files are available […]
High-voltage FLASH programming on ATTINY85
ATTINY85 High-Voltage Flash programmer @ td0g.ca: The Atmel ATTINY85 is a great chip (cheap, easy to use, supported in the Arduino IDE). Unfortunately it only has 5 IO pins, which limits its usability. There are guides on using a High-Voltage Programmer (HVP) to change the Reset pin into an IO pin. However, that prevents you […]
Building a pulse oximeter
John Keefe made this DIY pulse oximeters, that is available on Github: The heart (ha) of the project is the Pulse Oximeter and Heart Rate Sensor, which includes the sensor itself, a tiny brain to make the measurement calculations, and two “Qwiic” connections. Qwiic is Sparkfun’s system of making it easier to wire up sensors. […]
UHF version of TinySA
DuWayne KV4QB posted his UHF version of TinySA project: I had started on the TinySA from Groups.io HBTE, but am still waiting on some parts that I had orderd than have yet to show up. Looking around I found a UHF version that covers 240 to 940 MHz. This only uses a single si4432 transceiver […]