Experimental Seismograph Logger (Part 1) - PIC controlled, PC compatible, our experimental project offers you long-term data recording of the Earth's rock and roll events! The project constantly records data from a sensor that responds to any displacement between it and a reference source. The associated electronics can be set to respond even to minor earthshifts or vibrations. Can also be used with existing seismograph assembly that outputs 0-5V. The article also contains information, resources and further reading for those interested in exploring seismography in more depth.

Loft Light Alarm - This handy project is a low cost energy-saver that warns you by means of a delayed-action piezo sounder when the loft light is activated. Saves wasted electricity and blown bulbs. There is no direct electrical connection to the mains, instead a simple inductive-type sensor wire is utilised to detect mains activity. Simple to build, 9V operated, ideal for beginners.

PLEASE TAKE NOTE (MAY 2004) Page 236 Fig. 1 the value of R2 should of course be 470 ohms. The components list is correct.

PIC Moon Clock - ideal for romantics, or the odd werewolf, our PIC-powered project shows by means of a circle of 12 l.e.d.s the phase of the moon, from new, full, waxing to waning phases. Free source code available from the EPE web site.

Infra-Guard Monitor - In-car protection for young children, produced by EPE in response to a reader's request. This device monitors the boot/ luggage (trunk) area of a car, SUV or estate car and warns when young children have strayed into the area. Helps ensure your children don't climb where they're not wanted. 12V operation, the circuit uses a PIR to constantly check the luggage area of your vehicle.

Teach-In 2004 (Part 6) — Continuing our systems-approach introduction to electronics specially written for beginners and younger students. This month we suggest methods of sound level monitoring using bargraph l.e.d. drivers. Circuit diagrams of demo circuits are provided for you to build on solderless breadboards.

Also in this issue: Circuit Surgery - modified sinewave power supplies and inverter basics; Techno Talk asks whether fuel cells can save the planet. USB to PIC Interface review - could this module be the answer to many PIC user's PC-interfacing problems? Net Work - the Internet column suggests what the next trends in web site usage are likely to be. Interface - case-modding your PC with l.e.d. decoration controlled by your PC.