U-AMP – open source versatile audio amp

An open source universal audio amplifier called ‘U-AMP‘ @ GmanModz, that is available on GitHub: Using what I learned getting digital audio working on each systems, I set out on a new project I would call “U-AMP” (Universal-Amp). This would be ONE pcb which has the features of seamlessly integrated speakers and headphones with a […]

USB Morse keyer

Dilshan Jayakody writes about a new open source project, the PIC16F886 based CW auto key controller with USB support: USB Morse Keyer is a microcontroller-based auto keyer project with following features: *USB / straight key / iambic key inputs *Support for both standalone and USB operating modes *64-character USB typeahead buffer and 6-character Morse key typeahead buffer […]

A simple 8-channel receiver voting controller for enhanced repeater coverage and usability

KA7OEI has written an article detailing a simple 8-channel receiver voting controller: To simplify things, this voting controller sits in “front” of an ordinary repeater controller, taking the audio and COS inputs from the various receivers and outputting a single audio and COS signal. If the repeater system in question uses subaudible tones, it is […]

Mostly PIC16C57

CAPS0ff team posted an article taking a closer look at 8 “PIC16C57s”: We were recently sent 8 “PIC16C57s” from: *High Seas Havoc (403/C013) *Wargods (U69, C020) *MACE (U96, C021) *Carnevil (U96, C022) *BioFreaks (C023) *Gauntlet Dark Legacy (C024) *Gauntlet (U37, C025) *Blitz 99 (U96, C026) More details at CAPS0ff blog.

Building a giant USB three key mechanical keyboard

Glen Akins shares his latest build the giant three key USB keyboard: After seeing this giant mechanical keyboard at Adafruit, I decided I had to build my own. Adafruit made theirs out of wood and used one of their Python-compatible microcontroller boards. I wanted a sloped top on my keyboard. I also wanted to check […]

PIC18 four-channel DMX relay controller

Glen Akins has a nice build log on his four channel DMX-controlled relay, that is available on GitHub:  Halloween was right around the corner and I needed a timer with a bunch of relays to trigger some store-bought props and a fog machine periodically. (Mental note: read fog machine specs carefully—not all come with timer remotes.) My […]

RX/TX sequencer

Lukas Fässler has designed and built an RX/TX sequencer based on a PIC16F18325,  that is available on github: Much like the beacon keyer presented here earlier, this RX/TX sequencer is a simple but useful little device. Its typical use is in ham radio applications when a separate power amplifier (PA) and/or a sensitive low-noise pre-amplifier (LNA) is used. […]

Beacon Keyer

Lukas Fässler from Soldernerd published a project writeup showing how he built a PIC-based beacon keyer: This is likely the first ham radio related project that I document here on this blog But my very first PIC project was a beacon keyer that I made for my father, HB9BBD. That was in 2013. A beacon […]

CO2, temperature and humidity monitor

An open source CO2 monitoring project from Roving Dynamics: The project described below uses a MH-Z16 or MH-Z19 CO2 sensor and a DHT-22 (or DHT-11 if less accuracy is required) to measure the Temperature and Humidity. It has a 4 line by 20 character LCD Display to show the current readings and status, a warning alarm […]

Portable temperature, humidity and light ambient datalogger

A battery-powered small datalogger based on a PIC18F2620 microcontroller project from Jesus Echavarria: The idea comes a few months ago, talking with a friend. He needs something to  monitoring temperature and humidity inside a sea container, for a three weeks travel from Spain to China. Low consumption is important, in order to have maximum autonomy with […]

Programmable relay switch using PIC MCU (revised version)

Raj has documented his DIY programmable relay switch using PIC16F1847 microcontroller: Here are the summary of the features that this programmable relay switch has: On-board +5V voltage regulator (operates at 9-15V DC input) OFF and ON time setup for the relay operation Option for cyclic run (maximum 100 cycles, after which the timer stops automatically) […]

Development board for PIC16F1938

Raj over at Embedded Lab has designed a development board for PIC16F1938: The PIC16F1938 is a versatile 28-pin MCU belonging to Microchip’s extreme low power microcontroller family featuring nanoWatt XLP technology, 28KB of programming memory, 1KB of RAM, 11 ADC channels, and tons of other peripherals. A while ago, I designed a development board for this MCU and […]