September 2017

Compact 8-Digit Frequency Meter

This fully auto-ranging compact 8-digit DFM typically measures up to 55MHz+ and has a provision for a 1000:1 prescaler. It is an update on previous design ideas and uses three 600MHz high-speed op-amps at the front-end.

Displays frequency in Hz, kHz and MHz with 8-digit resolution on a 2-line backlit LCD. Full assembly and calibration details are included. Uses a PIC 16F88 with free .hex file downloadable via the link (right) or via our Library.

Micromite Plus Explore 100 (Part 1)

The Explore 100 expands on the Micromite Plus Explore 64 (see last month), adding more I/O pins,  PS/2 keyboard port and much more.  This article offers a comprehensive walk-through of the Explore 100’s featureset, with practical construction data next month.

Low-cost, compact attenuators

This interesting article offers a method of making attenuators using ordinary single-wafer rotary switches  without the need for elaborate multi-way Maka switch assemblies.

Circuit schematics and assembly diagrams are included. An invaluable practical guide to assembling attenuators around rotary switches.

Teach-In 2017 Introducing the BBC micro:bit
Part 4: Serial data transmission

The final part in our BBC micro:bit primer explores techniques for sending serial data to a host PC, using the wireless interface. A practical project is offered – a micro:bit wireless-linked tamper alarm.

Also in this issue

• Techno Talk – another roundup of likely technological breakthroughs
• Net Work – the Internet column introduces the latest Echo Show with colour LCD from Amazon
• Interface – the final column for EPE from Robert Penfold, who retires this month after a very long and illustrious career writing for Britain’s hobby electronic magazines. Robert signs off by describing the Raspberry Pi I2C expansion port. Wishing Robert well in his retirement.
• PIC n’ MIX – a simple PIC-powered sinewave generator
• Circuit Surgery – Ian Bell celebrates 20 years of writing our Surgery column by exploring aspects of high-frequency PCB design
• Audio Out – Jake Rothman tackles more ’looming problems’ with a practical run-through of interwiring techniques
• Max’s Cool Beans Blog – Max delves into the Radix 50 format, and that it implies
• Electronics Building Blocks – Solar LED lighting Control Module using a cheap-as-chips controller module

Next month

Precision Voltage & Current Reference with Touchscreen Control (Part 1); Micromite Plus Explore 100 (Part 2); Currawong Amplifier power supply upgrade; Teach-In 2018 – Part 1