Electrical pulses -> Computer

[nature boy]

lol. you just blew me out of the water with that. i have no idea what any of that means.
good luck with it all man.

[supersuk]

how cheap are you looking for?

This is my field of work.

[supersuk]

Are you riding this out? or is a trainer bike in your living room with your computer available?

Could just get a pic, arduino, atmel, motorolla or other cheap microcontroller, plus one of those dev board things so you have expanded memory and connections for i/o for about 30-40 dollars. Some packages come with pinouts for serial communications. Send data samples back to your computer through rs485 or 232 or other means. Thats probably the cheapest I can think of. You can write your own driver or software for your computer to grab it from the pic over the 485 or 232. I did something similar with a DC motor drive for a school project with about 150 dollars worth of electronics. If you build your own instead of getting the dev kit, and use a cheaper micro controller it would probably be alot less. Materials would probably cost you $5 for the controller, 5 bucks for a breadboard or pcb with lots of holes. A couple of small opto relays, voltage regulator, caps, wires and soldering for another 10 dollars. Extra memory and memory map chip for another 5 bucks.

You could probably just use a Raspberry pi, it has a GPio that you can wire up your sensor to. Probably want to put some sort of isolation between it and the sensor, optically isolated relay or something. Write your own software to convert the pulses from the IO.

You could also get PCI io cards for your computer to pick up any io you want. Not sure how cheap these go for but i'm' willing to be you can find a used one cheap on ebay or craigslist or something. The technology hasn't changed in the last 10 years or so with these. You could just use something like that if your trainer bike is at home and you have your computer nearby.

Last option is to use the fan feedback pin on your computer if its not used. Sometimes motherboards have a pin that hook up to fans that are able to provide feedback. Wheel spinning, fan spinning, same thing. If you're not using this, you can wire to this instead and write your software to grab from that address. You'll get rpms but i'm sure you can easily calculate speed and distance from that.

[supersuk]

Or you can pony up for some delta controls, You can store your info locally and also archive it remotely, you can read values remotely from a different computer, you can see real time data. Setup fancy widgets and guages to see what your bike is doing, speeds, history, charts, graphs and etc. see both consumption and demand. blah blah blah..

[supersuk]

you could probably just use the serial or parallel port on your computer. just use one of the data lines for your pulse signal and write your own driver as well.

Another neat idea that's cheap would be to use a keyboard. use your hall sensor and rig it up to one of your keyboards keystrokes, then you can parse a text file or whatever.

Another cool thing we did was that we created graphical recognition software. You can just use a webcam, point it at the readout on your rpm meter, then write software to dump that value into a text file or something every few seconds then you can calculate your distance travelled, speed and etc from there.

[supersuk]

Heres a 20 dollar option, ttl logic, you could probably get a 5vdc hall sensor and hook directly up to it.

8 gpio that you can connect over usb

http://numato.com/8-channel-usb-gpio-module

comes with a driver too, so write a small program to read the address , dump it into a text file or whatever.

[supersuk]

http://www.ebay.com/bhp/hall-sensor

hall sensors, some as low as a dollar

looks like you have a project on your hands, all doable for about 30-40 dollars.

[se7entse7en]

The intention was to use it while I was indoors on the trainer. I was hoping for a cheaper solution, something around $20 or so, but I ended up ordering a Suunto Movestick Mini and a Garmin Cadence/Speed sensor for just under $70.

Three main advantages are that it's wireless, the API with sample code is available for developers to create their own software, and finally, if I ever get a Garmin Edge GPS I would be able to take it out on the road as well.

I do like projects, though, so I may end up looking into making my own system someday anyway.

Thanks for the advice.

[se7entse7en]

I also found this site but thought it was a bit bigger of a project than I was looking for. Pretty cool project nonetheless.
http://blogs.msdn.com/b/netmfteam/archi ... ction.aspx

[supersuk]

one thing i saw years and years ago was some guy hooked up a micro controlller, hall sensor and a bunch of leds to his bike wheel.

when you pedal'd it the leds would display a picture that would not rotate. kinda like this

[nature boy]

whoa, shaun just hit keian's sweet spot.

[jeSteR]

[nature boy]

yeah, that's pretty much what i meant.