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A programmable programmablerobot robot you you can can build build––without withoutsoldering! soldering! In November, we introduced the Microbric range – an exciting new concept in electronic construction using screw-together “brics” (hence the name) on which various electronic functions were already built. N of mistakes is very much reduced ow we’re about to build one due to the modular construction. And of the Microbric “models” – a even the finished Viper is not the end nifty little programmable robot of the story: while it comes with both called the Viper! a bump sensor and infrared receiver, The beauty of the Microbric system there are additional packs which will is that soldering – the bane of beginlet you customise your Viper to do, ners and the worry of their mothers – is well, whatever you want him to. eliminated. The various circuit conMaybe you’re into Robot Wars (see nections are made when the devices SILICON CHIP September 2003). You are screwed together in the correct can add the “Sumo Pack” and turn manner. So no more than a screwdriver your viper into a fighting machine is needed to build a Microbric project with a flipper. Or perhaps add a sec– and even that is supplied! ond pair of wheels with the Motor and In many ways, Microbric can be thought of as a combination of electronics and Lego or Meccano. As they say, it’s “fuel for the imagination.” • Easy to build! To be launched in selected News Ltd papers this month • No soldering! (with a likelihood of others later) • Reusable! is the I-bot robot. For SILICON • Fun! CHIP readers, though, we’re going with something a little more • Programmed in BASIC (BASIC ATOM) ambitious . . . • 16 input/output pins Features: The Viper The Viper is a programmable robot which is easy to construct – but offers the user incredible satisfaction. You still get “the thrill of the build” but the likelihood 40  Silicon Chip Wheels add-on pack. Or a line-tracking module. And so much more. In later issues we plan to look at some of these packs and add on to the Viper we’re describing here. But let’s say you’ve built the Viper and customised him and now you’re looking for new challenges. Does that mean the Viper sits in the cupboard and languishes? Not on your life(buoy)! All of the components which make up the Viper are reusable: simply unscrew the modules and you’re ready to make something else. • Each motor module has an onboard microcontroller • All modules have current limiting on inputs and outputs • LED modules have high impedance input using Mosfets for switching A brief recap Last month we explained the ingenious Microbric system and how it went together. Just in case you missed it . . . Microbric is a system of interconnecting electronic modules which enables quick and easy building of complex systems. At its core is the patented Microbric Edge and connector “bric”. Each edge has three connectors: +5V, ground and data. When you connect the brics together, you connect these three connectors. siliconchip.com.au The Viper Motherboard, ready for assembly. The beauty of the system is that all the soldering is done for you! The brics themselves attach to a pre-assembled and task-specific module. There are microcontroller motherboards, communication modules, motor modules, sensor modules, human interface modules (buttons, switches, etc), and LED modules with many more planned for the future. Let’s now return to the Viper. It has an ATOM microcontroller board at its heart, to which are attached various Microbric modules: a pair of motor modules (along with wheels), two battery holders (each contains three AAA cells), the bump sensors, two LED modules, some switches, a piezo . . . and of course, we mustn’t forget the cosmetic modules which give the Viper its unique looks! The microcontroller The double-sided “main” PC board, contains not only the microcontroller but also a power supply, RS232 interface and provision for battery packs. Around the edge of the PC board are 16 bric interfaces, known as Pins. These are labelled P0 to P15. It is to these that the various functional modules are attached. To connect a module, line up the red dot on the appropriate module with the red dot on the motherboard at the required pin and fit a Microbric “bric” into the holes on the edge of your LED module. The tiny pins on the Bric fit into the holes; one way it will sit straight but the other way (the wrong way!) will sit crooked. Finally, the three screws are firmly tightened to complete the connection. Programming The microcontroller in this case is an ATOM and is programmed in BASIC. This is a variation of the BASIC language that is very widely taught and used in education, so the Viper is a perfect partner for school computer courses. Programming is undertaken via the serial output of an IBM-type computer. An RS232C socket and interface on This is one of the two motor modules used in the Viper. It’s unusual in that it has two PC boards in the one module. Most modules are one double side, 20.3 x 20.3mm PC board. As you can see, everything is preassembled – all you have to do is screw them together in the appropriate places! board programs the chip. If you’re not yet quite up to speed on BASIC, programming for the Viper is supplied. To write programs and to get the Microcontroller to read them, you need to install a program which is provided on the CD-ROM called BMAtom.exe. You need to install this before we can do any programming to tell your motherboard, or robot what to do. To do this, double click on BMAtom.exe to run the set-up. Make sure the program installs into the folder C:\Program Files\Basic Micro ATOM IDE 2.2. It will ask you to restart you computer. Do so. Construction There will be a set of more detailed instructions included with the Viper, but the general arrangement is as follows (use the photos as a guide): (a) connect all the modules to their appropriate pins (ensure you use all three screws) as follows: Viper Pack Modules The basic Viper Pack should contain the following: Motherboard( CPU) module 2 LED modules Slide switch module Buzzer module Button module 2 Motor modules Bump sensor module Infrared receiver module Assorted passive and cosmetic modules 2 battery boxes Infrared remote control Wheels & tyres CD of programming software Programming cable Screwdriver 20 “Brics” and heaps of screws, spacers and nuts siliconchip.com.au December 2005  41 Here’s how the “brics” screw together, connecting the power and data lines at the same time. We’ve shown more of this detail in the illustration at right. The 2 LED modules to P0 and P12 The Bump modules, with bumper attached, to P13 and P15 The motor modules, with wheels attached, mount from the underside of the board to P1 and P11 The pushbutton switch module to P6 The backsweeps to P4 and P8 (no electrical contact or function) There is nothing connected to P2, P3 P5, P7, P9, P10 or P14. (b) fit the two battery packs to the motherboard using the four countersunk head screws and nuts. When screwed hard down onto the motherboard, contacts on the battery packs mate with contacts on the board and the circuit is completed. (c) Fit the skid (the long metal rod with blue plastic tip) in place of the centre screw on P14 (underside of motherboard). Testing The Viper should now be complete. After checking that all modules are in the right places and they are all screwed in correctly, put the batteries in their holders (the right way around – negatives toward springs) and apply power. The red LED under the RS232 socket should light to show the Viper is powered up Programming Once your bump robot is built you need to program it. You do this via your personal computer (assuming it has a serial port – some newer ones don’t): 1. Open the program, BumpRobot. bas in BasicMicro IDE from your CD-ROM 2. Save the program (File/Save As…) to a location on you hard drive. 3. Connect the serial connector to the motherboard’s serial port 4. Click on Program to download the program onto your Bump Robot microcontroller on the motherboard. 5. Disconnect the serial connector. 6. Press the button on the Button Module to start your Bump Robot. You’ll find a lot more details on programming, including how to make the Viper do a lot more things that you want it to do, in the documentation that comes with the kit, More than that, the BASIC ATOM programming manual is also in- cluded on the disk so you can learn as much (or as little!) as you want about this language. Once you have learnt BASIC, you are well on you way to understanding most of the other common programming languages. There’s also a lot more information on the Microbric website (www. microbric.com). And we haven’t even looked at the infrared control capabilities yet (that programming is also on the CD-ROM). Next month, we’ll look at using the infrared remote control before moving on to the expansion packs. ! Please note: the Viper photographed on our front cover this month was an early prototype with some differences from the one featured here. SC Where do you get the kit? The Viper kit should now be available from all Dick Smith Electronics stores, (Cat K-1800) Recommended retail price of the basic Viper kit is $199.00 42  Silicon Chip siliconchip.com.au