Let's Make Robots!

Created: Forum topic

AD & DA converters - at a total loss.

I'm doing some non-robot project to learn more electronics. And boy have I got a lot to learn!
Right now I'm trying to take an analog signal, convert it into 8bit digital info through an AD converter, and then back to analog using a DA converter.

GM3/GM9 strength at low voltage?

I need help from someone who owns a solarbotics geared motor type GM3 or GM9, or even better: both!

I wantot to know how strong they are when driven directly from a single AAA 1,5 Volt battery. If you hook it up to the battery and hold on to the axle/output shaft, will the motor be able to spin itself around? Would it be able to keep spinning if you taped the battery onto the motor body, or would the added weight of the battery be to much to keep whole contraption rotating around its own axle?

Windshield wiper motors, have you tried'em?

Have any of you experimented with windshield wiper motors? I know they've been used in budget robotwars fighters. I just need to get an idea what kind of strength they have (with the original gearbox).
Will it be able to pull 20 Kg vwith a 20 cm diameter wheel mounted directly to the output shaft? what abot 50 Kg? -or a 100?

dance like a robot

We've all seen guys (let's admit it, it's always guys, never girls) dancing "the robot". But this guy seems to be dancing "the Asimo"... How meta-cultural is that? -A person mimicking a a robot designed to mimick a person!

The music isn't really my cup of tea, but the dancer is worth the hassle. 

 

 

upgrading from small motor

Let's say I have a motor control circuit that's too small. It could be the motor output of a Picaxe, the adafruit motorshield for arduino or a the innards of an old RC toy. The main thing is that it has two output wires, both capable of delivering positive and negative to make a motor turn both ways.

What if you want to use a bigger motor that needs more power? Below are three circuit diagrams

motorkontrol.jpg

how-to LMR meet-up

Inspired by the 2 years anniversary text on the LMR front page, I got to wondering

What do we require to make a successful LMR meet-up in real life?  

Yes I know we're spread all over the world, and anything higher than a 2% show-up rate would be a unbelievable. But what kind of physical preparations would one need? A large conference room with enough electrical outlets, loads of tables, PA-system and presentation equipment, and short distance to a bar and a cheap-ish hotel.

What else?

how to calculate motor strength?

Is there a common formula for finding required motor strength?

If I know the total bot weight and wheel diameter, could I find out what kind of motor I need. I know that gearing will come into play, but I dont know anything about these physics thingys so I choose to phrase the question as vaguely as possible.. 

Like, what kind of specs would a motor for a scooter (with me on top of it), doing 35km/Hrs require

or,  an offroader weighting 10K, doing 3km/Hrs with 10cm big wheels in rough terrain?

laser pointer and a 38khz sensor

would it be possible to make a laser flicker at 38khz?

I was thinking; if I had a modified laser that gave me a red dot that pulsed at 38Khz. If a robot was made to go towards a 38Khz beacon...

I thought this might function as a intuitive remote control.

The robot is programmed to do whatever, map its surrounding, search for metal or filming the girls gymn locker room. But when the laser is pointed anywhere in its vicinity it'll start following the red dot until the laser is switched of again. then it will continioue its original task.

RC power for my picaxe

I'm using RC ESC's to drive the motors in my current robot project. These speed controllers has a built in power regulator (called a BEC) that is meant to power your RC receiver. I've measured and the voltage produced is a steady 5.03 Volts.

Can any of you think of a reason why I couldn't or shouldn't use this as power source for my Picaxe 28x1 ? 

 

Can't seem to insert hyperlinks with Opera browser on my old iMac, so here are a link if you wanna read more about RC ESCs or BECs

http://en.wikipedia.org/wiki/Electronic_speed_controller

finding cheap RC ESC (speed controller)

I love RC ESCs. They are electronic speed controllers that you connect to a servo output on a RC receiver or a micro controller, and they give you full step free control over a big motor in both direction. Most of the ones made for RC cars work in the voltage range 6-8.4Volts, but there are several alternatives for people who plan to run up to 24 volt motors in almost constant stall at a gazzilion amps (read robot war contenders).

But I'm the eternal cheapskate, and wants the cheapest there is.. So far I've found this