Let's Make Robots!

Gareth's new dinner table?

For some reason, it made me think of Gareth and his "Theo legs"...

"Excuse me, waiter, can I get this to go?" ;^>


TED talk invitation to Frits

He announced this in the Shout box:

fritsl: I was just invited to do a TED talk. Not sure, any input from you guys appreciated :)

and I hope I am not being too presumptious by opening a topic so this doesn't get lost in the shout box.

I absolutely think he should do it. Some shouts:


super cheap video recorder


Anyone tried one of these (or similar):


I am tempted to get one. Around $8 to the US. I would just about double my investment putting a micro SD card in it. I would really like to find it as a component that cheap, but I haven't seen one. I guess I could rig a servo to press the power button and then the record button.

Trying to regulate 5v from 7.4v

I have a LM2930S-5.0:


in this mess:

I have a cap across the input and a resistor in line on the output (it was 6.8 before I added the resistor).

Yes, it is a cheap meter, but measuring VCC on a Mega I get 5v and on a Fio 3.3v. It is reasonably accurate.

What am I doing wrong? I don't want to smoke my 5v uC. The VR should be putting out 5v (datasheet says 5.5v max).

Can I recharge a shared battery?

I just started messing around with a little RC boat (yet another way to emulate and test things for the bigger boat project I am part of) and it is getting the Fio that had been the brain in my AGV before I upgraded it. Anyway, the boat is small enough that to limit size and weight, I am going with one of those scary ol' LiPo batteries. One nice feature of the Fio is that it has an on board LiPo charger that will charge a 7.4v.

very simple motor control

I am a software guy who easily gets over his head in circuits. When it comes to controlling motors, I like the ESC because I understand how to use it but it adds a lot of cost. I look into H bridges and most seem overly complicated. This little circuit seems simple anough to understand and implement:


EDIT - NEVER MIND - Looking for this antenna in US


EDIT - I was going to try to make a directional antenna work for homing, but open sky GPS turns out to be accurate enough.

Or one similar:


I found it listed one place in the UK for  about 13 Euros, but they don't take small orders and I didn't even ask about US.

The important details that would make one similar are:


Frequency: 433 - 435 MH z

homing / directional proximity at 50' and less in choppy water

No longer a hot issue; GPS on open water is dead on accurate...

I need to make a bot seek a beacon. I think I am going to have to concede that GPS will get me within 20' reliably but I can't count on getting closer. For safety's sake, I want to double that but would consider things with a lower limit. Anyway, lets say I get within range and get a "blip" or whatever and can home in following it. What tech will do that?

It is likely to be in rough seas and might be dark.

Robots at CES


I want to see the robot on a unicycle out on the show floor; talk about a bull in a china shop...