Projects in the September 2006 issue of EPE Magazine

The No. 1 UK Magazine for electronics technology and computer projects
Smart Mixture Display for your car — track your fuel mixture in real time with this LED bargraph. See the operating modes of the engine's ECU and be forewarned if a catastrophic high load 'lean out' occurs. This Smart Mixture Display monitors your car's oxygen sensor and airflow outputs, and gives an audible warning if mixtures go dangerously lean. You can also incorporate the LED display into your car's dashboard. Straightforward electronics assembly for experienced electronics/ auto electrics enthusiasts.
Low Cost 50 MHz Frequency Meter — an accurate autoranging design featuring a 16 character LCD. This compact 50 MHz DFM is battery or mains operated, 20mV - 85mV input sensitivity. Input impedance 1.1M in parallel with about 10pF. Range 0.1Hz to 50MHz ±20 ppm accuracy. Based on a PICmicro PIC16F84P, free source code available from our Downloads page.

LED Torches — ideas for a range of deceptively simple LED torches (flashlights). This interesting article shows how a stepper motor can be used as a hand-cranked generator, in order to power an array of high-efficiency white LEDs. Plenty of scope for testing your resourcefulness and improvising from whatever surplus items you have to hand. Our article shows 'step by step' (no pun intended!) how to build your own LED torch, with a series of photographs and full guide notes.

Water Level Gauge — A measurement device for checking the level of water stored in a garden water barrel. Provides a remote display on a simple bargraph. Uses an LM3914 bargraph driver controlled by a pressure transducer. Our fully illustrated project shows all the necessary details in full colour to enable you to build the project with confidence. May also be adaptable to other applications.

ALSO IN THIS ISSUE: Techno Talk — does the future rest in fibre or cable? Practically Speaking — our hands-on workshop series looks at switch and potentiometer connections. Teach-In 2006 our flagship tutorial series focuses on electromagnetic wave and the radio spectrum, with constructional details for a simple radio receiver. Circuit Surgery — our reader helpdesk looks at CMRR (common mode rejection ratios) for op.amps. PIC n MIX - how small can a PICmicro get? Some of the tiniest MCU's available. Net Work (the Internet column) demonstrates a low cost webcam security application that will upload images to a web server - or email them! All this and more in the No. 1 UK hobby electronics magazine. Subscribe now!