November 2016

Fingerprint Access Controller

A powerful keyless entry system that uses a fingerprint scanner to activate an electric door strike, ideal for doors, security gates or the garage.

Enrolling up to 20 fingerprints, the fingerprint scanner module can be mounted on a plain pattress box and has a blue backlight, while the system controller has a menu-driven LCD and is mounted indoors. Variable timer strike period, built-in anti tamper routines, PIC 16F88 controlled.

Cheap programmer for the PIC32

A simple, low-cost programmer to help you program recent projects that use the PIC32. Utilises an Arduino Nano and is built on a piece of good old-fashioned Veroboard.

Compact Hybrid Switchmode 100W Bench Power Supply (Part 3)

The third and final instalment of our 40V/ 5A DC input bench PSU covers the installation of the PCB, chassis-mounted hardware and interwiring. Details of the custom case hardware and panel meters are also included.

Parts List Errata

In last month’s issue we specified 8 x BC547 and 12 x BC557 transistors.  Due to the boosted voltage rails some transistors may not withstand operating at higher voltages.  We suggest constructors substitute BC546/ BC556 transistors respectively. Also we omitted from the Parts List a 200mm length of 10mm dia heatshrink.

Introducing the Arduino
Part 10: Ultrasonic proximity sensing

Continuing this excellent tutorial series focussing on the Arduino, our Teach-In tutors examine the techniques for using ultrasonic sensors for proximity or distance sensing. Code listings and circuitry of a proximity warning system are included.

Audio Out

Our audiophile expert offers a hands-on review of the Hobby Creek Hands multi-purpose benchtop holder/ vice.

PIC n’ MIX

PICs and the PICkit 3, a beginner’s guide (Part 6), with a real-world application of a traffic light simulator.

Also in this issue:

• Ingenuity Unlimited – some prize-winning readers’ ideas
• Techno Talk – fascinating news about the pitfalls of LED street lighting
• Net Work – revisiting the Pure Evoke Flow Internet radio and ideas for alternatives
• Interface – ideas for enhancing the Raspberry Pi’s timing capabilities
• Circuit Surgery – the fundamentals of op.amp amplifiers and their stability
• Max’s Hot Beans – Max’s dips his toes in VR headsets
• Electronics Building Blocks – a variable frequency driver based on a cheap and cheerful  op.amp module, ideal for LEDs, sounders and more besides

In next month’s issue:

Universal Loudspeaker Protector; 9-Channel Infra Red Controller; Revised USB Charger/ regulator with low-battery cutout; Teach-In 2016 (Part 11): Arduino and GPS.