August 2021

Ol’ Timer II

This project offers a much more relaxed approach to the important matter of telling the time. It displays the time in plain English by utilising a colourful 8×8 ‘backlit’ matrix of words. In keeping with its laid-back design approach, its ‘word cloud’ type display is updated on every quarter of the hour. Adjustable brightness with ambient light sensing. Setup is via USB or integrated capacitive touch buttons. Based on a PIC16F1455 microcontroller and DS3231 real time clock chip.

Surface mount components are used throughout. Good soldering skills are needed to complete this project successfully.

Low-cost Wideband Digital RF Meter

This low-cost Digital RF Power Meter utilises an Arduino Nano and will be very useful for anyone who needs to measure RF signals from 1MHz up to 6GHz. It has an LCD display and USB interface, and is a straightforward, simple to build design using a pre-built RF detector module.

Switchmode Replacement for 78xx regulators

The 78xx series of three terminal regulators has been a staple for building cheap regulated supplies for half a century, but they are not always the most energy-efficient way of regulating a d.c. rail.  This little switchmode project is a drop-in TO-220 style replacement using a surface mount switchmode i.c. and will offer 3.3V to 24V output voltages at up to 1A, depending on your choice of component values. It has a dropout voltage of just 0.5V and does not require a heatsink.

Surface mount components are used throughout. Good soldering skills are needed to complete this project successfully.

Max’s Cool Beans

More on the ‘Victorian style’ multicolour, multi-segment alphanumeric display and driver control system

Audio Out
Microphone Preamp for Vocoder (Part 4)

Concluding the project with some modifications and options, and lots more besides!

Kick Start (Part 4)

Introducing the Arduino Pro Mini: investigating this attractive minaturised version of the popular Arduino Pro, with a handy guide to ports and a sample application to get you started.

Also in this issue:

• The Fox Report – questioning some security issues with mobile provider Three
• Tekkiepix – early press releases reminding us of the early days of Compact Disc manufacturing. Remember to visit the Tekkiepix gallery at https://tekkiepix.com/
• Techno Talk – How Weller and Antex became market leaders in soldering irons
• Net Work – Haier’s WiFi refrigerators, anti virus choices and other Internet news
• Circuit Surgery – Transformers and LTspice simulations – Part 3
• Make it with Micromite: Part 31: Using the Cricket Module (June 2021 issue) with a Micromite

In next month’s issue:

The Night Keeper Lighthouse children’s nightlight; Compact Crystal-locked Audio DDS Oscillator; High-power Ultrasonics Cleaner; USB HiFi SuperCodec