Sweeperino, Arduino based test instrument


Ashhar Farhan (VU2ESE) made an Arduino based sweeper for ham radio homebrewing, that is available on GitHub:

The Sweeperino a very useful Arduino based test instrument. It is the following:
*A very stable, low noise signal generator from 4 MHz to 160 MHz without any spurs
*A high precision power meter with 90 db with 0.2db resolution
*A sweeper that can be your antenna analyzer, plot your crystal or band pass filter through the PC
*It fits in your jacket
*It can be assembled in an evening
*Costs about $50 in new parts

See the full post on VU2ESE’s radio experiments blog.

Simple DataFlash board


David Johnson writes:

This is a small board that plugs into one of the headers on an Arduino Uno or other board to provide 4Mbytes of non-volatile storage
It works with either 5V or 3.3V boards, and is based on the low-cost 4Mbyte Winbond W25Q32FVSIG DataFlash chip. It is ideal for applications such as data logging, playing audio samples, and storing text.
I also describe a simple DataFlash library to interface to the board.

More details on Technoblogy.

Programmable seven segment LED tester


A Seven segment LED tester project from Arduino Enigma:

Here is the finished Seven Segment Tester. All of the available Arduino Nano pins, except for analog input pins A6,A7 and Serial Port pins D0 and D1 are connected. This leaves us with 18 pins to bring to the 3M Zero Insertion Force (ZIF) socket. Any display up to 9 pin DIP can be tested.
Here are some pictures of the device testing a 16 segment display, a 7 segment display and a 3 digit 7 segment display. The common cathode and common anode versions are programmed as test patterns.
Once the Arduino is programmed, the device can work standalone using a 9v battery.

More details on Arduino Enigma Machine Simulator blog.

Check out the video after the break.

63 dB step attenuator

stepatten front

DuWayne published a new build:

While I was working on the power meter function for the latest version of the SNA, I used several fixed attenuators for checking linearity and calibration. It would be a lot easier if I had a variable step attenuator. I have several digital controlled attenuator modules that I bought one eBay a while ago, and I guess it is time to use some of them. There are several models available. The ones I plan on using are the simplest with only 6 control pins for a total attenuation of 31.5 dB in .5 dB steps. I am going to connect two in series with the control lines paralleled for a total of 63 dB in 1 dB steps.

See the full post on his blog.

USB mini media keyboard


Sven Krasser built a small USB keyboard input device for media control and wrote a post on his blog detailing its assembly:

The project is based on a Pro Micro, an Arduino-compatible ATmega 32u4 board (the 32u4 allowing to easily create USB devices). For iteration 1, I added a couple of buttons and a rotary encoder to a breadboard alongside the Pro Micro to see how I can get media controls over USB to work. Turns out, Nico Hood’s HID library makes that quite simple.

Minimal ATSAMD21 computer


Johnson Davies shared detailed instructions of how to build an ATSAMD21-based computer on a prototyping board using a 32-pin ATSAMD21E:

If you’re looking for something more powerful than the ATmega328 in the Arduino Uno a good choice is the ATSAMD21. This is an ARM Cortex M0+ processor with up to 256KB flash memory, 32KB RAM, and a 48MHz clock, so it’s substantially better equipped than the ATmega328. In addition it has a USB interface built in, so there’s no need for a separate chip to interface to the serial port.
Arduino have designed several excellent boards based on the ATSAMD21, such as the Arduino Zero or smaller-format MKRZERO. However, these boards are an expensive way to use an ATSAMD21 as the basis for your own project, and they probably include many features you don’t need.

More details on Technoblogy.

Arduino interface for TFA9842AJ power amplifier


Dilshan Jayakody writes, “I tested a couple of TFA9842AJ based amplifiers in the last couple of years. The main reason I liked TFA9842AJ is its simple, clean design, wide operating voltage, and high-quality bass-rich audio output.  Thanks to it’s built-in DC volume control circuit this audio amplifier can easily interface with MCU. In this article, we provide a generic TFA9842AJ module which works with most of Arduino boards, MCUs and SOCs.”

See the full post in his blog.

Arduino Shield for CAT M1 and NB-IoT modems


Michael Krumpus designed and built an Arduino shield for Nimbelink Skywire CAT M1 and NB-IoT modems, that is available on Github:

Nimbelink has a development kit for use by product developers, but it’s rather expensive. I wanted to try out a Nimbelink CAT M1 modem without the dev kit, and since there are so many hobbyists using Arduinos out there, I wanted to provide a nice Arduino library for the modem. I chose the Nimbelink module based on the Sequans Monarch CAT M1 modem and got to work designing an Arduino shield to hold it.

More details on Nootropic design Project Lab site.