$20 08m Bot

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Svejk

Senior Member
Finally, I think I've finished my quest to make a ~$20 (NZD) picaxe bot.

This version uses 08M (08M2 in transit) and I think is easy to upgrade to 14M2 to provide more I/O.

For motion I've used 9g servos modified for continous rotation (from e**y), and the "grey scale" sensor uses photodiodes and an opamp plus 2 white LED's.

Schematics, PCB artwork and how to build will follow if enough interest raised.

A little video showing it in action can be watched here.
 

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S

Svejk

Senior Member
I'm making an upgraded version using 08M2/14M2/20M2/20X2 footprint which I'll document properly and post it here later.
 
S

Svejk

Senior Member
I've had the opportunity to play with a few models of bots and in most cases there are a couple of drawbacks commonly found:

- the batteries (accumulators) are hard to replace, yet this is one of most used consumable;
- the sensors, motion and signaling hardware is fixed or require some awkard interfacing.

Considering this, I've had the ideea of making one minimal daughter board, containing the pcb mounted battery holder and the IC and support passives on the other side with all IOs made available via pin headers connected with a flat cable. As most periferic hardware uses ground and +v I've made it available on 3 way headers for each IO pin.

Therefore there are no practical limits in developing new hardware and mounting it wherever suits. For example, to make an LED indicator, the board will contain ground and IO connection, a resistor to suit and the LED. A potentiometer feedback, for an arm position for example, would be connected straight to ground, +v and IO pin. IR or 433 Rx/Tx modules would be just as easy to interface.

The motors can be either modified servo's (like the ones in post #1) or driven via a custom made board with LD293 or anything else to suit.

The proposed schematic and a couple of shoots of intended pcb are attached. The size of pcb is choosen to replace the lid of a standard 83x53 jiffy box providing an inexpensive chasis.

Edit: The picaxe shown is 20x2 but due to common power and serial pins of 8/14/20 ICs anything can be used.
 

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