1750Hz tone generator

Dilshan Jayakody published a new build: The 1750Hz tone bursts are often used to trigger repeaters. There are several methods to build 1750Hz tone generators which including TC5082 divider, using MCUs, etc. In this post, I present another 1750Hz tone generator which I built using 74HC4060 high-speed 14-stage binary ripple counter and 7.168MHz crystal. In […]

Open Trickler: The DIY smart powder trickler

Eric Higgins has a nice build log on his Open Trickler project a bluetooth-enabled smart powder trickler from off-the-shelf parts for under $60: Fundamentally, this is not a hard problem to solve. Read the value from the scale, run a motor that moves powder into the scale, turn off the motor when the scale reads […]

Homebrew DMX-controlled RGB LED light

Glen has written an article detailing his homebrew DMX-controlled RGB LED light: This project is a small DMX-512 controlled, color-changing RGB LED light. The light can be controlled via the DMX512 protocol or it can run a number of built-in programs depending on how the software is configured. The light incorporates an advanced 16-bit PIC24 microcontroller with […]

Piggybacking USB onto an industrial push button

Glen Akins has written an article detailing his USB-connected big red button project: In this project, I mount the electronics from my single-key USB keyboard project to the back of an industrial mushroom push button switch. The finished big red button now activates my screensaver with a single overly-large button press. The biggest issues in this […]

Resistive load, constant-current power supplies, and a 3D printed desk lamp

Dr. Scott M. Baker published a new build: In this video, I build a 3D Printed Desk lamp. The basic design came from Thingiverse, but I repurposed my LM2576 Constant-Current design to serve as a dimmer.  It all started when I found an interesting lamp on thingiverse, which used 75mm air hose segments from another […]

Raspberry Pi based indoor air quality monitor

Dr. Scott M. Baker made this Pi-based environmental monitor and wrote a post on his blog detailing its assembly: For years I’ve followed the “uRadMonitor”, a device that does air quality monitoring and radiation monitoring. I’ve played with geiger counter projects before and frankly found them to be not very interesting. However, the idea of monitoring […]

Building the ultimate USB power distribution system

Dr. Scott M. Baker published a new build: My goals include: 1. The ability to switch each device on/off with a rocker or toggle switch 2. Current limiting capability via a fuse or similar device 3. Overvoltage protection 4. Visual indicator (LED) of operational status 5. Multiple independent outlet See the full post on his […]

Solar powered weather station

Antalife has written an article detailing the build of his a solar powered weather station: To expand my microcontroller and programming knowledge I have decided to try and make a Solar Powered Weather Station. My goal is to record parameters like: *Temperature *Humidity *Air pressure *Air quality (something to do with CO or CO2) I then hope to send […]

Simple I2S stereo decoder with amplifier

Dilshan Jayakody published a new build: In this project we build simple I2S stereo decoder with amplifier. To decode I2S data we use Princeton Technologies PT8211 16bit DAC. KA2206 audio power amplifier is used as driver stage of this system. Structure of this I2S amplifier is self-explanatory from the schematic. We select PT8211 and KA2206 […]

A transmit converter (and amplifier) for 630 and 2200 meters

KA7OEI has a great write-up on building a transmit converter for 630 and 2200 meters: As the name implies, a transmit converter takes another frequency – such as that produced by a conventional HF transceiver – and converts it to another frequency.  In my case I use an FT-817 – a low-power (5 watt) all-mode, […]

Pro mini logger project for the classroom

Edward Mallon writes: Dr. Beddow’s instrumentation class has been building the 2016 version of the Cave Pearl datalogger for more than three years, and feedback from that experience motivated a redesign to accommodate a wider range of student projects while staying within the time constraints of a typical lab-time schedule. The rugged PVC housing from […]

Solar powered WiFi weather station

A detailed instructions of how to build this weather station project by Open Green Energy: This Instructable is a continuation to my earlier weather station project. It was quite popular on the web, people around the globe made their own by following it and given valuable feedbacks for improvement.By taking consideration in to the comments and Q&A […]

The Boris Beacon – A 1mW solar powered hifer beacon

Dave Richards (AA7EE) has written an article detailing his 1mW solar-powered HiFER beacon project, the Boris Beacon: In this post from May of last year, I detailed the construction of a 1mW solar-powered HiFER beacon. I named it the Boris Beacon, in tribute to my neighbor’s cat. The beacon was never mounted permanently outside. I kept it […]

DIY Arduino based RC transmitter

  Dejan over at HowToMechatronics posted a detailed how-to on building DIY Arduino RC transmitter: Now I can wirelessly control any Arduino project with just some small adjustments at the receiver side. This transmitter can be also used as any commercial RC transmitter for controlling RC toys, cars, drones and so on. For that purpose it […]