Cycling, Meet LabVIEW

[travispape]

A lot of jocks are installing the LabVIEW Runtime engine on their home computers today.  Here’s how it came to pass:

Back in April, I bought an iBike power meter for my cycling hobby.  It logs bike speed, wind speed, road slope, and some other parameters, but most significantly rider power.  I really enjoyed it, but very quickly found that there were several opportunities to improve the data with post-processing and started working on a LabVIEW program to do just that.  

It didn’t take long for me to see that it was shaping up as a good program and back in June I presented it to the company.  The owner of the company is a Mac guy and his number one concern is that the program works on both Mac OS and Windows.  When I told him how easy it is to do that with LabVIEW, he was sold on the idea.  Of course the size of the LabVIEW Runtime engine is a drawback, but he was willing to deal with that since it makes it cheap for him to offer the cross-platform product.  

They contracted me to make the next version of their Win/MacOS software and it was released yesterday, replacing their former offering.  It interfaces to the power meter, saves files, and does a lot of processing on the ride files to really dial-in the accuracy and gives the rider an easy way to drill into his/her ride.  The company is providing the program for free.  It can be downloaded at www.ibikesports.com and it comes with a sample file so that you can put it through its paces.  If you are curious to see one programmer’s attempt at creating a multi-platform program using LabVIEW for a consumer product, take a look.

By the way, I have been programming with LabVIEW since version 2, and this is the first time that I used LabVIEW’s facility for associating physical units to floats.  This seemingly-mundane feature is such a gem--I wish I started using it years ago!  It has made it ridiculously easy for me to support either metric or English units that different cyclists are used to.  The calculations in the program deal with speed, watts, air density, pressure, temperature, weight/mass, etc.  LabVIEW took a huge burden off my shoulders by handing all the units so easily.  It has also prevented a lot of mistakes--not only does a broken wire force you to get the syntax right, it also forces you  to get the physics right!

The last I used Mac OS was version 7.1 back in the early 90’s--another lifetime ago it seems.  I was really happy with how easy it was to port my Windows work to Mac in this project.  I only need to use NI-VISA runtime for the interface, so the hardware interfacing was no problem.  I have a dozen or so conditional compiler structures sprinkled through the code--not a big deal.  However, the MacOS platform starts falling short with the lack of the installer build specification.  I really need to be able to build a Mac installer.  I heard Dr. T talk about supporting the Mac platform at his session at the last NIWeek--a Mac installer build spec would be a great way for NI to demonstrate that Mac platform commitment.

Also, I’m really interested in learning the other ways that LabVIEW has made it into consumer products. Are there any other products out there that are starting to propagate the LabVIEW Runtime Engine?

Travis

[johnsold]

Travis,

I tried to download the program from the ibike site. First it crashed Safari. Then when I tried to unzip the downloaded file, Stuffit Expander 12 gave an error message.

I was going to show it tonight to a friend who is a serious biker.

Lynn

[travispape]

I just downloaded the mac zip file and everything worked fine for me.  Did you get the whole thing?  Win2K reports the file size as 46,218,752 bytes.

It is just another download, so I'm not sure why your Safari wasn't happy about downloading it.

[altenbach]

Hey, this looks cool. 🙂

What did you use to make the executable installer, because it seems that our corporate firewall blocks the download. I switch to a VPN so I am downloading it now...

I wonder of this device could also be used as a general datalogger for other purposes, e.g. in a model rocket, etc. 😉

[travispape]

One of my favorite little tools, WinRAR.  Has someone blacklisted WinRAR for executable installers?

I'm guessing that you are in jest with the model rocket idea, but the iBike is a little too optimized for the biking application to pull off the rocket application.  It would actually do a fine job measuring the wind speed, acceleration, and elevation, but there's the little matter that it measures vehicle speed with a spoke magnet & counter.

We'll start working on the business case to cover the model rocket market straight away.  🙂

Travis

[SportSci]

Hi Travis,

I am new to Labview, but I am really interested in your program, experience and abilities for building this cycling VI. I tried to find it on the link you provided, but was unsuccesful.  I am a sports scientist who is interested in controlling an electronically braked cycle ergometer, but haven't got a clue where to start.  The bike (brand name: Velotron - same company that makes computrainer) gives an output through a stereo wire, and I am told that the program runs the same at that used for Lode bikes. 

Do you have any experience or insight that might help?  Do you know if this type of VI exists?

Thanks in advance...any help you could provide would be much appreciated.

[travispape]

Sorry, no Velotron experience and my application does not interface to it.  Try googling Velotron and LabVIEW--it looks like it turns up some links that might help.

The links for Mac and Windows builds of my application for iBike are here:  http://ibikesports.com/downloads.html

Travis

[battler.]

Hi, nice work.

Can you post some screen shots of the actual parts (UIs) of this system which were developed using LabVIEW?

Did you need to purchase separately both LV Pro for Windows and LV Pro for Mac?  I have dev. suite which doesn't appear to include LV for Mac.

You say that it was easy to convert existing LV for Windows project to LV for Mac project?  True?  You merely open the project is different versions?

What are some quirks of the Mac OS you need to know about when converting VIs from a Windows LV project?  For example, some of my projects access the Windows registry.

[johnsold]

battler,

You need to have separate licenses for LV for Windows and LV for Mac. NI has never released a cross-compiler.  If you look at the Idea Exchange, I think you will find some requests for that feature.

How easy it is to convert depends on how much platform-specific code is in the project.  DAQmx does not exist on the Mac. Timed structures. There are Data Socket and TDMS limitations, although they can be used to some extent.  ActiveX. And others. On some things the Help files are quite specific about items being Windows only while others are vague or do not mention it at all.

What are you doing with the registry? Are you determining the environment, changing it, or something else? There are ways to do many of the things on the Mac, but the methods may be different.

Lynn

[battler.]

Hi johnsold,

I use the registry to determine the environment such as Win X86 or 64.  I also use registry for security and even extract things such as MAC address and disc serial no. etc.

I use plenty of ActiveX and .NET.

I wonder if there is an article about this very problem; converting Windows app into Mac.  We're finding (unfortunately) that more customers are asking for it...