Tabletop Photovore

The challenge - build a simple self-powered robot that would look for the brightest spot on a table, but not fall off the edge.

I used pager motors for the legs and feet, photodiodes for eyes, a 4700 uf capacitor for the stomach, a Miller solar engine for the drive, and a 74HC240 for the brain.

Category:

Howto & Style

Tags:

• autonomous
• robot
• solar
• cell
• photodiode
• photovore
• bicore
• diy
• miller
• engine
• beam
• Geilich

[TheVarnster]

it just looks like a stopmotion video sorry but i just think it does...

[mgeilich]

It looks like stopmotion because it is speeded up. The 'vore moves pretty slowly and the video was too long for youtube at normal speed.

[stopmojim]

I see. I'm thinking if you blacked out that white line on the tabletop edge, the bot may not see enough difference and head over the edge. Particularly, if the light source is directly in front of the bot. So, since it has photodiode eyes I'm assuming this is not a FLED based popper. Are you using the 1381 trigger type solar engine (Beckingham block-later called the "Chiu" design) or the Miller type?

[mgeilich]

Miller. The 1381 is a 'J'.

[stopmojim]

How does it sense the edge of the table? And when it is at the edge, isn't it looking directly into the light source? Why does it turn away?

[mgeilich]

The light sensors are photodiodes turned downwards so that they are picking up reflection off the table top. When a light sensor is 'ooking over the edge of the table, no reflection.

[keithosmarferrer]

that miller solar engine is so slow, you should change the resistor value and the capacitor to have a big charge,

[ilovesteaksnscience]

how many mili amps and volts does the solar panel generate?

[TheVarnster]

oh rite cool (or not)

[sosyapyedir]

eee ne şimdi bu insan bir açıklama yapar

[Jabmechtech]

Very cool. I like the simple use of the downward facing photodiodes. awsume bot!

[stopmojim]

I see. Well done too BTW. I've built 100s of these poppers but never a Miller version. Is there a schematic somewhere on the net?