# creating exercise machine for a research - need help

We are hoping to create our own exercise machine for a research in which we need to program the bike to fit our custom resistance pattern that would change over short time intervals. Our outcome measure, or performance measure, is RPM. We will tell the subject that their goal is maintain a certain RPM (e.g. 40 revolutions per minute), and that’s all they know. Behind the scenes, we want to be able to apply a resistance pattern and there should be flexibility so that we can program any resistance pattern we want. For example, one resistance pattern could be something like this:

1 kg —> 5 kg —> 7 kg —> 2 kg —> 10 kg —> 4 kg, etc. and keep repeating this pattern during a trial, with each interval (—>) lasting 1 minute ( or any period we decide).

Here are my questions:

Can we use an arduino MC for this ( I know we can use Arduino for RPM but what about resistance?)

Should we build a new hardware or can we use any bike like SCIFIT, take the circuit board out and use our own MC?

The Arduino could control some circuit that in turn controls the resistance.

Let us know the details of that circuit and we can help.

I know my excercise bike moves a magnet to increase resistance. I would have to take another look at it to see exactly how that works, but yes an arduino could definitely handle the project.

Can we increase the resistance ( electro magnetic ) by programming Arduino using labview?

The Arduino could control the mechanism that increases the resistance.

Labview could also control that mechanism, so there would be no need for an Arduino.

Well, my question is how can I make my bike communicate with labview? I mean read the resistance then change it with labview ( aka how can make my bike & labview talk to eachother?)

Your question can't be answered unless you tell us exactly how the mechanism to control the resistance works.

I just emailed SCIFIT and asked

This is what SCIFIT emailed back..

The board measures the magnetic resistance and power the generator uses and calculates the resistance. It is not a trivial calculation to explain. At this time I cannot help further with the calculation from the board.

Is there a way with multi meter I figure out how to read the resistance from the board ?

No. You need to "reverse engineer" the entire board, which is a technically challenging task.

I'm not surprised that the manufacturer refuses to give away trade secrets.

AHHHHHHHHHH crap…
do you suggest any other way to do this project?

Find someone who can reverse engineer the board, and you should be good to go!

Lots of people do this for fun, by the way.

Maybe you can use an electric brake. Couple the shaft of the brake to a shaft on your wheel. I do not know the resolution of the breaking force though so you will need to do some homework to see if it would work.