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The CYBOT Sonar Processor Board

HOW IT WORKSMODESPROBLEMSDOWNLOAD


HOW IT WORKS

The microcontroller

The device used is another ELAN device, as discovered by Nigel Goodwin.
You can download the datasheet from the
Download are on this page
You will notice on the schematic, that the ELAN is pin for pin with the 18 pin Microchip devices

The micro uses a 4MHz resonator, maybe due to accuracy for the ultrasonics.

The reset problem is now fixed, a reset management (brown-out) circuit is used to reset the processor 1 microcontroller and the UC2 micro.

Full circuit diagrams are available on the Download of this page.

At issue 13, you now get 4 beeps at power-up to indicate the selected operating mode.
The beeps may be long or short, depending upon the switch settings.

The operating mode is selected by pins 10, 9, 8 and 7 of the 13 pin connector to the SONAR IO board.
These pins are pulled up to +5v by resistors on the sonar processor board.
Mode selection uses a 4 way DIP switch to connect these pins to 0V

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OPERATING MODES

A table of operating modes is available in the communications pages.

Line following, without waiting for the next issues

Selector Switch
You can build a small switch block ( Pictures in the
Download area )
The pictures show the switch in light seeking and line follow mode.
Cybot will line follow with only switches 2 and 4 on, or 2, 3 and 4 on.
Right now, I don't know the difference.

Cheap'n'Dirty method

The simpler method: (Pictures available in Download area)

1. Ensure Cybot is switched off.
2. Get hold of some solid wire, no more that about 0.6mm diameter
3. Cut 3 equal'ish lengths about 3 - 4cm
4. Insert one end of each wire into holes 13, 9 and 7 of the sonar PCB Underside picture  Top side picture
5. Twist the other free ends together. Picture
6. Switch on and off it'll go.

NOTES:

Cybot is better on a white background and matt black lines.
I tested it on a LEGO MINDSTORM vision command mat.

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PROBLEMS

So far, this board has had no reported problems.


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DOWNLOAD AREA

UC2 Board Schematic
gif
pdf
zipped pdf


Datasheets
EM78P156 Microcontroller

Pictures:
UC2 PCB top view (with switch pack added for line follow mode)
UC2 PCB underside
Reset Circuit - uses R3, R4, R5 and Q1
Light seeking mode switch setting
Line follow mode switch setting
Underside view of switch pack mod

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