Hexbug Hack
HexBug Hack
1 Possibilities
2 What's Inside
3 Controller Design
4 Assembly
5 Controller Software
6 Testing, Programming --and Final Assembly
7 Downloads
8 Upgrades
Give your Hexbug a Real Brain!
Chapter 1 - Possibilities -
Hexbug Hack
The Hexbug is a very cleverly designed, tiny toy robot bug. Once removed from its package and switched on, it marches forward until its antennae bump an obstacle. It then does a reverse-right turn, and continues forward again until the next obstacle. A loud noise (like a hand clap) will also cause it do its reverse-right turn.
This simple ‘reflex’ response looks very much like a real insect. It does apear like it is exploring its environment. But this is a robotic insect. Shouldn’t robots be smarter?
The designers of the Hexbug, Ignition, Inc. and Innovation First, Inc., decided to display the electronics by placing the circuit board on top of the main chassis and under a transparent ‘bug’ shell. This design provides an excellent and easy to use chassis for a much smarter bug. Disassembly is fairly easy, but does require some soldering skills. A new circuit board with a Microchip PIC microcomputer can then replace the stock board and be programmed to match the Bug’s original, simple reflex behavior.
(It might not seem cost effective to add $25 of controller electronics to a $10 robot, but that’s the wrong perspective- How about building a $25 robot controller board and being able to get a $10 pre-built robot chassis for it?)
Now the real fun begins. Even though the Hexbug’s motion is limited, with the addition of a few simple sensors and some clever programming, it can do remarkable things. For example, a right turn (the only direction the Bug can turn) is accomplished by doing a reverse turn for about 2 seconds. How can it make a left turn? Simply do a right turn for 6 seconds - 3 right turns equal one left turn.
(Solving these types of problems- finding functional solutions using very limited resources- are the sort of challenges NASA has had to face when thing go wrong with distant space craft. The only thing that can be done to solve the problem is to upload new control software.)
With these small additions, the Bug can now be programmed with new, additional behaviors. Some possibilities:
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The Bug could periodically ‘sleep’ instead of just marching along, avoiding obstacles until it’s switched off. While the microcomputer is in ‘SLEEP’ mode, almost no power is used. The Bug could be active for 30 second, and then sleep for 2 minutes. The Wake/Sleep periods could be made random to give it behaviors closer to a real ‘bug’.
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The Bug could be given programming to use a piezo-buzzer to make sounds as it explores. This would definitely give it a ‘Personality. (What would Scrat be without all his funny sounds?)
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The Bug could be programmed with a musical scale and could ‘sing’ for special occasions: Happy Birthday, We Wish You A Merry Christmas, Who Let The ‘Bugs’ Out....
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The Bug could monitor its own battery voltage, and ‘Cry’ for new batteries when its power gets low.
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The Bug could be given a light detector, and be programmed to seek the brightest place in its environment.
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The Bug could ‘go to sleep’ when it’s dark, and be randomly active when it is light.
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The Bug could be equipped with rechargeable batteries and solar cells. With a light detector modification, it would look for a bright place to recharge when it detects its batteries are getting low.
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The Bug could be equipped with an IR-control module and programming to read the signals from a TV remote. This could provide direct remote control, or a means to remotely program a ‘behavior’ (explore/march/dance) into it.
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The Bug could be programmed to seek out a ‘charging station’ that uses an IR transmitter similar to the TV remote to park and recharge its batteries.
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The Bug could be equipped with a microphone and tone decoder and software so it could be controlled using a tone generator, and could also ‘talk’ to other Bugs with the same type programming.
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The Bug could be equipped with IR Proximity sensors to detect the edge of the desk/table it’s walking on. Two would be needed: center front and rear-left. There is the chance that the Bug could walk up to a corner, with the edge of the desk/table on its left. A left-reverse turn would but it over the edge. It would have to detect this condition, and then ‘cry’ for help.
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The Bug could be equipped with an Electronic Compass for navigation. (Distance traveled would still be ‘open loop’.)
1]The micro-robotic Hexbug is the result of collaboration between Ignition (Plano, TX; www.ignition.com), an industrial design and development firm, and Innovation First Inc. (Greenville, TX; www.innovationfirst.com), a product engineering company. RadioShack is the exclusive North American retailer of the Hexbug. Bandai, the leading toy manufacturer in Japan, also recently signed a deal for global distribution rights, with plans for other products to follow. “We had a rough idea for this product, but Ignition brought it to life,” says Joel Carter, VP of marketing at Innovation First. “They transformed our concept into a viable market-ready product and helped us to create an entirely new product category.”