Let's Make Robots!

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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:

http://ruggedcircuits.com/html/circuit__7.html

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:

http://www.proant.se/Gismo/files/440/datasheet%20twingain%20434.pdf

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.

Get more components on a small breadboard
You may just look at the picture and say "well, duh!" and not need an explanation, but here it is for those that want it... Read more

Robots at CES

http://www.cbsnews.com/2300-205_162-10006227.html

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

Knock off nunchucks and an import ESC

EDIT - I pretty much talked myself into the nunchucks and will report back someday about how they work. I am a bit more concerned about the ESC as it has the potential to cause a lot of damage if it fails.

Anyone used any of the knock offs?

Brushed electric motor interfere with GPS?

On my AGV, I am losing GPS updates when I am in motion, or to be more specific, when I turn the back wheels with the big brushed motor. It is on an Arduino and I know about a potential soft serial and servo library issue, but it doesn't happen if I only turn the steering servo.

MY AGV development platform

 

I decided to do this as a blog as I plan for this to be a long term test platform as I mess around with different tech along the way.

OK I started by buying this RC truck chassis on eBay:

It uses a 7.2v NiMH battery and powers the motor using an ESC that delivers a few AMPs of 6v through a BEC to power a transceiver and the steering servo. Instead of a transceiver, I am hooking up an Arduino Fio and various components, housing them in a project box: