Actions
Forum Thread Details
  • State Not Answered
  • Replies 4 replies
  • Subscribers 58 subscribers
  • Views 584 views
  • Users 0 members are here
Related

Bicycle cadence and speed logger

Former Member

First of all wanted to start by saying that I'm not very savvy with electronics, but am willing to dabble in it.

 

As a bicyclist I am interested in logging my speed and my cadence during my trips.  I am not able to find any commercial product that can do that (at least nothing in the low price range that I'm looking at).

I did find online someone who made one using an Audrino: http://www.mwilliams.dsl.pipex.com/datalogger2.htm, however, it seems expensive and is not detailed enough for me to replicate it.  I am hoping that someone would like this challenge and design a very simple logger without an Audrino and document the steps for others to replicate.

 

Here is what I envision: logger logs time (either actual time or simply a counter from the start point) and the number of pulses it sees from the reed switch of the bicycle wheel and the pulses from the peddles.  No need for a display.

 

Any suggestions?  Anyone interested in the idea?

Parents
  • 0

    Hi Vadim,

    This could be accomplished with just a CPU, a battery and a couple of reed relays or hall effect switches. The program in the cpu would simply need to count the number of wheel rotations and the number of crank rotations in a 10 second period and store these 2 bytes every 10 seconds. I would mount 4 magnets on the wheel and four on the crank to provide better accuracy. This would tell you how fast you were going every 10 seconds, how far you went each 10 seconds, how many crank rotations you made in the same period and what your crank rate was. The uncertainty due to the magnets being mounted  a quarter turn apart would average out over multiple readings. Just a few lines of code is all it would require. You would get a sequence of 2 byte pairs recorded at 10 second intervals. I would use something like a BasicX module from Netmedia or a ZBasic module from ZBasic as these are self-contained solutions that don't require any other costs to implement - the development systems are free. Arduinos are also feasible, if you can find a small and inexpensive variant. The Hall effect switches or reed relays could be connected directly to the module. If you use reed relays, be sure your software allows the reed switch to bounce for 15 milliseconds when closing or opening without counting extra pulses and set the input pins to have internal pull-up resistors.

    Doug

Reply
  • 0

    Hi Vadim,

    This could be accomplished with just a CPU, a battery and a couple of reed relays or hall effect switches. The program in the cpu would simply need to count the number of wheel rotations and the number of crank rotations in a 10 second period and store these 2 bytes every 10 seconds. I would mount 4 magnets on the wheel and four on the crank to provide better accuracy. This would tell you how fast you were going every 10 seconds, how far you went each 10 seconds, how many crank rotations you made in the same period and what your crank rate was. The uncertainty due to the magnets being mounted  a quarter turn apart would average out over multiple readings. Just a few lines of code is all it would require. You would get a sequence of 2 byte pairs recorded at 10 second intervals. I would use something like a BasicX module from Netmedia or a ZBasic module from ZBasic as these are self-contained solutions that don't require any other costs to implement - the development systems are free. Arduinos are also feasible, if you can find a small and inexpensive variant. The Hall effect switches or reed relays could be connected directly to the module. If you use reed relays, be sure your software allows the reed switch to bounce for 15 milliseconds when closing or opening without counting extra pulses and set the input pins to have internal pull-up resistors.

    Doug

Children
No Data