Other nerds will appreciate this. Take the following things and add them together:
Cateye wireless cadence/speed computer
When it’s built, pics will be posted.
isn’t there error in the power calculation based on the tire-trainer interface? how do you plan to calibrate the system?
overall, sounds really cool! i’m impressed, man. god, i’m (we’re) lame…
I must be a nerd because I think this is cool!
How did you get the powercurve onboard a chip? Is it an Altera type of device?
Any idea how accurate this will be? My guess is it will get you to +/- 15% maybe. Depends on how you derived the power data I guess. If you could calibrate it you would be set.
Keep us posted.
I’m basically building a wireless version of what Kurt sells as a power meter for their fluid trainer. They have the power formula fit for their trainers posted on the website. The chip is a standard programmable computation chip from a company like Altera. The place I work has them lying around in the machine shop, so I swipped one with the foreman’s permission.
I figure the best this thing can do is measure to within 10% of actual power. The largest errors introduced into the calculation come from the cubic term in P=Ax+Bx^3, so one is safe in ignoring any other sources of error.
You might consider a submitting this to Make Magazine – The first magazine devoted to digital projects. You’ll be famous!! 