Search found 5 matches

by donwilson
Fri Jan 13, 2006 11:18 am
Forum: Robotics
Topic: robotics information
Replies: 6
Views: 4777

Re: robotics information

I have the Lego Mindstorms. It is a fun way to get started. Everythings snaps together so it is very easy. You use a Windows PC to build your programs in a graphic environment and download your programs to the robot using a USB to IR module. The controller is limited however, I think three inputs an...
by donwilson
Thu Jan 12, 2006 3:45 pm
Forum: General Discussion
Topic: multiple conductors?
Replies: 7
Views: 1253

Re: multiple conductors?

That's right. Assuming you are using two wires the same gauge and length you should have 50% of the total current flow through each. A good thing to remember is that current divides in parallel and voltage divides in series. For example, I sometimes test 240V traffic light outputs from solid state r...
by donwilson
Wed Jan 11, 2006 6:29 am
Forum: General Discussion
Topic: Microcontroller circuit to sense bicycle RPM
Replies: 8
Views: 1446

Re: Microcontroller circuit to sense bicycle RPM

Thanks everyone, I have the bar graph working now using an Atmel ATMEGA16L microcontroller. It is a lot of overkill so far. I'm using less than two percent of the program space. I'm using the INT0 interrupt input and software debouncing to make sure a certain amount of time passes before it will acc...
by donwilson
Sun Jan 08, 2006 6:50 am
Forum: General Discussion
Topic: Microcontroller circuit to sense bicycle RPM
Replies: 8
Views: 1446

Re: Microcontroller circuit to sense bicycle RPM

Thanks Philba. It is just two wires. I was wrong about it being a coil. I just now connected a meter in ohms and it is open when the magnet is not present and about .5 ohms when the magnet is present. It must just be a reed switch. I thought a switch would wear out too quickly. Anyway, that makes it...
by donwilson
Sat Jan 07, 2006 8:47 pm
Forum: General Discussion
Topic: Microcontroller circuit to sense bicycle RPM
Replies: 8
Views: 1446

Microcontroller circuit to sense bicycle RPM

Hi Everyone, I am building a simple stationary excercise bike from an old bicyle. I have the magnet and sensor from an old bicycle odometer and speed computer. The magnet attaches to one of the spokes and the sensor is mounted on the frame to detect the magnet each time it passes. I think the sensor...