August 2023

This month’s highlights

Wide-Range OhmMeter (Part 1)

This sophisticated auto-ranging ohmmeter will measure just about any resistance, from milliohms to many megohms. At its heart is a PIC24F microcontroller and readings appear on a 16×2 LCD display. The circuit and principles of operation are described in detail this month, with construction following in Part 2 next month.

0-110dB RF Attenuator for Signal Generators

Originally designed to accompany our AM/FM Signal Generator (May 2023), this project could be combined with just about any signal generator to provide easy output level adjustment over a wide range. Utilises an Atmel microcontroller with source code available from our website.

Some surface mount components are used. Good soldering skills are needed to complete this project successfully.

SPY-DER 3D-printed robot

SPY-DER is a speech and web-controlled surveillance spider robit that walks like a spider and can ‘spy’ using its on-board camera. It uses a Raspberry Pi Zero W and camera, and an Arduino Nano, but best of all, you can make it yourself using 3D-printed parts, some servos and some off-the-shelf modules.

Universal Battery Charge Controller – 2023 update

This update enables the original project (December 2022) to be built using more readily-available components, saving a bit of money at the same time.

PAS CO2 Air Quality Sensor Module

Continuing our series of articles describing low-cost air quality sensors (LCAQS), this month we take a close look at a sensor module based on photo-acoustic spectroscopy (PAS) – namely the Infineon XENSIV PAS CO2 mini board. We show how to connect one to an Arduino and capture CO2 readings in ppm.

Also in this issue

  • Techno Talk – In years to come, will Artificial Intelligence be doing many things that humans do?
  • The Fox Report – stuck in a loop between eBay and Royal Mail over proofs of delivery
  • Net Work – How Chinese EV makers plan to conquer Europe, a flat-pack mini EV car, the mission to Mars to bring samples home to Earth and more space news.
  • Circuit Surgery – an exceptional in-depth insight into ‘ideal’ diode integrated circuits and their principles of operation.
  • Max’s Cool Beans – Arduino Bootcamp (Part 8): Max presses onwards and upwards with his crash-course in Arduino coding for beginners.
  • Audio Out – some sage advice for those wanting (or needing) to downsize their collection of electronic ephemerals, this month our audiophile expert takes a hammer and chisel to old gear in search of valuable parts, before bidding them farewell.
  • Make it with Micromite – more considerations and progress on the Smart-Light Controller

Next month

GPS-synchronised Analogue Clock; Mini LED Driver; Wide-Range OhmMeter (Part 2). Contents may be subject to change.

August 2023 files for download -


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