Comments on: Tiny Braitenberg vehicle

By: kshitij

kshitij — Mon, 07 Dec 2009 05:03:47 +0000

wow!! looks cool thanks for putting it! Good for beginners! can’t wait to build!
THANKS!

By: AVR Based Tiny Robot Braitenberg vehicle - Microcontroller Project Circuit

AVR Based Tiny Robot Braitenberg vehicle - Microcontroller Project Circuit — Fri, 13 Nov 2009 02:44:35 +0000

[...] Tiny Robot Project Documentation and Source Code tinkerlog.com [...]

By: MiCAHEL

MiCAHEL — Fri, 06 Nov 2009 03:17:07 +0000

CANT WAIT TO BUILD IT!

By: Meurig

Meurig — Thu, 05 Nov 2009 13:51:24 +0000

I’ve re-read the datasheet and you are (of course) correct about the MCP1700 not needed much voltage differential: typically 178mv + 3% of the output voltage for anything above 2.5V.

This seems to suggest that it would be fine provided the battery stays about (1.03 * 3.3 + 0.178) 3.58V. So only really while the battery is fully charged.

I believe the required input voltages are 3.27V, 2.75V and 2.3V for the 3.0V, 2.5V and 1.8V regulators respectively. Since you’re using the ATTiny25V the 2.5V would seem the ideal choice having an input voltage below the batteries deep discharge point and an output well into the input range for the chip. Of course, this change in Vcc will probably impact the design of the rest of the circuit…

By: Alex

Alex — Tue, 03 Nov 2009 19:09:12 +0000

Hi Meurig,
the MCP1700 is a low drop regulator, that means it should be stable at least at 3.4V, if I read the datasheat correctly.
The idea is to run the controller and all other components at 3.3V and only the motors and the transistors at what the battery delivers (3.7-4.1 V).
Cheers,
Alex

By: Meurig

Meurig — Tue, 03 Nov 2009 09:21:59 +0000

A quick question, which I’m guessing is related to the 5V confusion above, you’ve mentioned you used a 3.3V MPC1700 voltage regulator – but that would need a min input voltage around 4.3V, right?

You’ve used the ATtiny25V which is good down to 1.8V, so I’m guessing a 1.8V or 2.5V voltage regulator made it into the final circuit?

By: Meurig

Meurig — Fri, 30 Oct 2009 18:12:14 +0000

This is seriously cool

I’ve got most of the parts on order, everything from the AVR programmer upwards! It might take me a while (and I think it’s going to have to be a bit bigger, my motors are 12mm diameter) but I’ll let you know how I get on.

By: Tiny Braitenberg Vehicle â€“ The Cutest Movable Vehicle! - Scientific, embedded, biomedical, electronics contents.

Wed, 14 Oct 2009 05:14:25 +0000

[...] Vehicle sounds like a bit Deutsch for you here? Well, For those who didnâ€™t notice, the Braitenberg Vehicle is actually a masterpiece from the Mr. Valentino Braitenberg, a biological cybernetics professor [...]

By: Alex

Alex — Fri, 18 Sep 2009 17:44:56 +0000

Yes, you are right, that should be 3.7V.
3.7V of the lipo battery is used to power the regulator and the motors. The pager motors are 3V I think. They had no rating.

By: Ciccio

Ciccio — Fri, 18 Sep 2009 16:01:46 +0000

Great projet, congratulations.

In your design you specify 5V but then you are using a 3.7V battery. Could you explain a bit more please?
Also the pager motors. Are they 5V?