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And now for something completely different similar! Putting PEBBLE to work! Mount a Seismograph on a Protoboard, PEBBLE it then transfer it to a KPB. What’s a KPB? Read on! by Stan Swan A powerful 7.8 magnitude earthquake – the biggest experienced in the Shaky Isles for 80 years – occurred in southern New Zealand during the early evening of July 15th last. Had you owned a Seismograph, you might have known about it virtually straight away. The earthquake fortunately struck in a very remote part of the South Island (Dusky Sound-Fiordland) and damage was minor, with no injuries or deaths. Few Kiwis in the more populous North Island even felt it! However as a tribute to the massive power of the event, it transpires that this NZ region has been measurably twisted slightly out-of-shape. Once the shaking settled, the net result in that region has been a land raising of about a metre, along with a sideways shift westward approximating a handspan. Yes – NZ is now (fractionally!) closer to Australia. With memories of the Boxing Day 2004 magnitude 9.3 Indian Ocean tsunami still painfully fresh, Australian east coast alerts (and even some precautionary Lord Howe Island evacuations) promptly developed. Thankfully these concerns proved a false alarm, as only mere surges – no This map shows the locations of the Australian and Pacific Plates, with the site of the NZ July 15 earthquake, right at the junction of these plates. higher than normal ocean waves – eventuated trans-Tasman. However, closer to the quake source, waves of 1m high were experienced, and even in remote Hawaii handspanhigh rough water was noted. The event served as an excellent test run of the Australian Tsunami Warning System (ATWS) and as a reminder that devastating earth movements can strike at any time, with no warning. New Zealand sits above an area of the earth’s crust where the Pacific and Australian tectonic plates collide and earthquakes are a regular occurrence. Kiwis reckon lots of small quakes (to relieve pressure) are better than a single large rumble! The Dusky Sound quake was certainly no mere pebble splash however and it has triggered renewed interest in earthquake monitoring overall, perhaps even with an eye on the holy grail of eventual prediction. Seismograph We mentioned before a Seismograph which is, of course, a device used to The Kiwi Patch Board, a PC board which is has the same hole spacing as a 23-way Protoboard but has many extra features. It can be used to transfer protoboard layouts to PC boards. 72  Silicon Chip siliconchip.com.au both monitor and, with the right equipment, measure earth movements. Readers may recall the September 2005 SILICON CHIP Seimograph article by Dave Dobeson. This detected delicate earth movements and vibrations by pendulum displacement, with deviations optically monitored by a LED/LDR combination. These READADC values were then handled by an opamp and PICAXE-08M to yield a classic earthquake “squiggly line” seismic trace display. Dave’s design is still perfectly valid and motivated readers may already have nervously thumbed through dog eared SILICON CHIP magazines looking for details. But wait – here’s a fresh layout approach involving PEBBLE! Kiwi Patch Board Taking the breadboard/protoboard concept one step closer to permanency, a so-called “Kiwi Patch Board”(KPB) has now been developed which essentially allows the direct transfer of the classic 23 x 10 breadboard layout onto a PC board which has exactly the same hole pattern and spacing. The KPB is a quality fibreglass and silk-screened PC board measuring ~90mm x 45mm. It has many “extras” over the breadboard, including space for a 7805 regulator and smoothing capacitor (or other 3-pin regulator if you aren’t using a PICAXE), 3.5mm PICAXE programming socket, screw PEBBLE diagram of the Simple Seismograph (SILICON CHIP September 2005) control transferred to protoboard – but exactly the same layout can be used to populate a Kiwi Patch Board. There’s also room for the “extras” such as the voltage regulator, sensitivity pot, programming socket, etc. terminal, header pin and support mounts, dual supply and even extra rails under the IC. The KPB is now available in Australia from MicroZed and sells for $6.75. The approach involves doing initial circuitry development on a solderless breadboard,using PEBBLE as a layout refinement aid. The advantage of this technique is that components and links on the final working breadboard design can then be progressively swapped over and soldered onto a the KPB. Such “paint by number” style assembly can be very confidence REG1 7805 100 D1 1N4004 IN +5V OUT IN LED1 K boosting! Of course, this goes against traditional PC board design somewhat which call for as few links as possible – but being able to switch between breadboard and patch board with exactly the same appearance means much less likelihood of misteaks misstakes misst . . . errors. In fact mounted circuitry can look so professional that projects may not even progress to a dedicated PC board. Educational acceptance of the KPB has been very strong here in NZ. Kiwi educators, keen to both improve GND GND A   LDR1 OUT 100nF 10k K 470F 9V DC IN 470F CON1 SERIAL OUTPUT CON2 DB9F SENSITIVITY VR1 100k A 470F 25V 7805 VANE ON SEISMIC MASS 1 6 10k 2 7 3 IC1 741 4 6 VR2 5k 4 3.3k 1k 10k* (SEE TEXT) 3 Vdd P0 P1 P3 2 3 IC2 5 PICAXE P2 -08M SER 2 IN P4 Vss 5 22k 8 H L E 10k 7 3.3k 10k LED SC  2005 SIMPLE SEISMOGRAPH LOGGER OUTPUT 1N4004 A K K A The circuit diagram of the Simple Seismograph, reproduced from the September 2005 edition of SILICON CHIP. Refer to that issue for complete operational details and the seismic mass which drives it. siliconchip.com.au September 2009  73 JOIN THE TECHNOLOGY AGE NOW with PICAXE Developed as a teaching tool, the PICAXE is a low-cost “brain” for almost any project Easy to use and understand, professionals & hobbyists can be productive within minutes. Free software development system and low-cost in-circuit programming. Variety of hardware, project boards and kits to suit your application. Digital, analog, RS232, 1-Wire™, SPI and I2C. PC connectivity. Applications include: Datalogging Robotics Measurement & instruments Motor & lighting control Farming & agriculture Internet server Wireless links Colour sensing Fun games Ben, a 17 year old electronics student at Hutt Valley High School, Wellington, NZ, finds putting it all together is so simple when he has PEBBLE to guide him. presentation and ease the agony many electronics novices experience with circuit construction, were predictably behind the KPB design. PEBBLEing the Kiwi Patch Board Although PEBBLE is essentially intended for basic breadboards, it’s been satisying to also have the moreinvolved KPB layout available under this versatile emulator. PEBBLE’s save and load facility pleasingly also allows designs to be emailed or set up as templates. Given the intended PICAXE slant of the KPB, the two resistors and inverted 08M programming layout may especially suit the latter. To further ease the quest, some components (in particular the screw terminals, 7805, smoothing capacitor and programming socket) have been pre-mounted. If these are unwanted then a trimmed KPB board can be selected from PEBBLE’s offerings. KP-Boarding the Seismograph Distributed in Australia by Microzed Computers Pty Limited Phone 1300 735 420 Fax 1300 735 421 www.microzed.com.au 74  Silicon Chip Components in the original 2005 earthquake detector were shown soldered onto a dedicated PC board and run from an unregulated 9-15V supply. Programming can be via the 3.5mm socket but an input has also been provided to suit the header pin style used in many SILICON CHIP PICAXE articles. Component placement onto a KPB under PEBBLE was almost “paint by number” but the ability to juggle board layout proved very gratifying. Such “cut and try” versatility, normally requiring extensive pen and paper planning and tedious wire stripping, made for great productivity. The bonus of a large-screen board view furthermore eased eye strain. Aside from the supply rail red and ground black, most wire colours shown here are not sacred and were simply selected for functional clarity. Many alternative layouts are possible for this circuit but with a further ground rail assigned in the channel under the ICs, the eventual wiring became very clear and direct. Readers with a keen eye for such things are encouraged to relate to this new PEBBLE version to both the schematic and original layout. NZ’s well known tectonic tendencies, also manifested as significant volcanic and thermal activity, means comprehensive monitoring systems have long been warrented here. Both Civil Defence alerts and web based seismic services (www.geonet. org.nz) are well established, perhaps reducing the need for a personal seismometer within NZ. Coastal Australian readers of a nervous disposition however may already have their soldering iron out and warming up . . . Resources, credits and references are hosted at www.manuka.orcon.net. nz/seismo.htm SC siliconchip.com.au