This project is based on my original schematic from the year 2005, when I also built and tested a perfboard prototype. I didn’t think much of it then, but, at least on the Internet, it has since become an exemplary circuit for the “passive Ethernet hub” in general. I’ve seen it featured in the prior…
I have been using a talking multimeter for years, almost every day, and I find it extremely convenient and useful. I am continually surprised that they are not in use everywhere. However, the Arduino part of my old design works with only a handful of multimeter models. This new prototype uses the SCPI communication protocol,…
This is a development of this prototype: The goal was to turn the prototype into a highly reproducible device that could be tested in a real ham shack by operators who wouldn’t have to change their radio setup (or their aesthetic taste) to accommodate the new gadget. It is also expected to serve as a…
A weekend experiment… I have never worked with Arduino Zero or its derivatives before. This SAMD21 board is from Aliexpress. It has the native USB port only and in at least one instance its PCB layout seems to be at odds with the Arduino IDE files describing Arduino Zero (see program comments). Still – it…
After you finish reading this article, please also read the sequel: This real-time Morse decoder uses the Goertzel algorithm to detect a CW tone of 708 Hz. In order to better isolate the useful signal, the program introduces comparing the magnitudes for three frequency bins – the central one and two adjacent ones on both…
Ovaj štit omogućava da se na Arduino Uno (ili Arduino Mega) lako povežu Bluetooth modul za serijsku komunikaciju i OLED displej. Na sam štit mogu se direktno umetnuti displeji širine do 27,4 mm (1,08 inča). Bluetooth modul može biti klasični HC-05, HC-06, ili noviji JDY-31, JDY-33, DX-BT04-E itd, već u skladu s potrebama projekta. Sami…
This shield was designed with no particular project in mind. It aims to be useful for both automatic and keypad-operated antenna selectors in general. This is just hardware, providing slightly more than a set of ten relay drivers, but there are many projects/sketches on the Internet (including this blog) that could be easily adapted to…
Gradio sam razne birače antena. Oni se po pravilu sastoje od dva dela – upravljačke i preklopne kutije, koje su povezane upravljačkim kablom. Zadnjih nekoliko godina ustalio se jedan model preklopne kutije, tj. kutije s relejima. Ona je za pet antena i predstavlja kompromis: bilo bi lepo da predviđa više antena, ali je i pet…
The FTDI drivers are easily available and often already present in the OS. The interface will present itself to the user as a new COM port. In Device Manager go to this new COM port Properties->Port Settings->Advanced. Then in the Miscellaneous Options section (bottom right) uncheck Serial Enumerator and check Disable Modem Ctrl at Startup.…