As fast as an NFL player?

Hey everyone,

N00b here...

My eight year old is showing interest in electronics and we're doing some of the basic experiments. He came to me after flag football practice and wanted to find a way to determine "if he is as fast as an NFL player". I thought this would be a cool project to work on. I was thinking that a simple set up with two infrared proximity sensors placed a short distance apart would work. He could run past the sensors and then we could calculate the time it took to cover the distance.

What do you all think? Is there a better way to do what we want?

Oh, and this would be a learning project for both of us.

--the dad.

Hi.
Doing similar project for my final Uni project. Attaching my outline if of any interest. Have worked through most of the
issues so far. I'm having to do this as a formal project, but I would guess that you can bypass a lot of this.
Carl

CarlJP:
Hi.
Doing similar project for my final Uni project. Attaching my outline if of any interest. Have worked through most of the
issues so far. I'm having to do this as a formal project, but I would guess that you can bypass a lot of this.
Carl

Thanks...how do get to the outline? Good luck with the project!

Hi. Not sure what happened there. This is the outline:

Sprints Timing System Project

Break-beam timing systems are a useful tool to measure the performance of athletes in a number of sports. My speciality is in athletics, where I am a sprints coach. Initial research shows that there a number of break-beam timing gate systems commercially available.

However, two problems arise with their use in a small club setting: firstly, the cost of such commercially available systems, many of which run into thousands of pounds, and the cheapest of which are in the hundreds of pounds, and thus are potentially inaccessible for the majority of coaches in smaller clubs. Secondly, the currently available systems can be limited in flexibility, both in terms of ways the runner can be measured and also the way the resulting data can be managed and stored.

For my TM470 project I intend to research and develop a relatively low-cost timing system, with variable methods of measurement and user control over the management of the resultant data. A key part of the system is its control via a laptop computer which will integrate with the timing gate(s).

A simple schematic of a possible basic system is shown below:

The final objective would be to produce a fully packaged complete system available for third party use with minimal training and at relatively low cost which reflects the flexibility required by a range of users. It may not be possible to complete the project to this level in the time available so I have broken it down into phases with appropriate and achievable milestones.

Phase 1

Produce a prototype system which has basic functionality, including accurate and repeatable timing, a basic user interface and a basic recording system. This will operate for a single runner.

This will involve:

• researching possible timing gate mechanics and electronics (i.e. how to stop the timer)and building gate and associated electronics;

• researching ways to communicate between the gate and the computer (probably via a micro-controller using either wired or wireless communication);

• choosing the appropriate programming language for the computer side of the project (using my experience with Java unless this appears impractical);

• identifying the elements that need to be integrated within the computer side programming (use of sound API for issuing commands, concurrency, communication with gate probably via micro-controller, data manipulation and storage, timing operations), and writing appropriate code.

• researching and possibly implementing use of micro-controller to manage computer to gate integration;

• researching user interface options and building a limited number for the basic system;

• testing the system for accuracy;

• maintenance of system documentation;

• maintenance and review of system costs.

Phase 2

Produce a prototype of an enhanced system which will improve on the phase 1 model by researching ways to allow for timing for multiple gates/multiple runners, and for more sophisticated ways of manipulating and recording timing data.

This will involve:

• researching most appropriate methodology for accurate timing of multiple runner (same gate/multiple gates);

• modify programmes to account for results of research;

• modify hardware/micro-controller software to account for results of research;

• modify user interfaces to account for modifications to system;

• identify useful types of data required by users, and modify programmes to produce and store these requirements;

• testing the system for accuracy;

• maintenance of system documentation;

• maintenance and review of system costs.

Phase 3

Produce a complete system for use by third parties, with documentation and installation software.

This will involve:

• researching ways in which elements of the system can be converted from prototype to final product;

• packaging the product in such a way as to enable the user to use it ‘out of the box’;

• write complete user documentation;

• consideration of on-going product maintenance requirements and implementation of systems to manage this;

• full cost analysis and consideration of a potential selling price.

Some elements of the project may change as a result of research undertaken, but the fundamental objectives should remain unchanged.

Hi. I'm using these:

http://arduino-info.wikispaces.com/InfraredBeamPair

They will initially run by cable to Uno, then link by serial to laptop. With appropriate displays, buttons etc, I'm sure you can do this without the laptop. Next phase will be to make it wireless.

Cheers

Carl

Thanks for the link and the outline!

Our first phase will be to run with the laptop. The second phase will add bluetooth and external power so that he can use it with his iPod Touch (his idea).

It would be whole lot easier to use a thing called a stopwatch.

Pete

Pete - Try being consistent with a stopwatch! Not as easy as it looks.

Astrodad - sounds fun for you both. Keep posting how you are doing. Loads of people here who will walk you through any issues.

Try being "consistent" in broad daylight with an IR emitter that has a 15 degree beam angle.

Pete

Pete - don't want to get in a pissing contest.

I'm a qualified timekeeper, and the typical error with a novice timer is at least 0.5sec.

I accept the possible limitations of the IR system, but hope to mitigate (as has been discussed on this forum some time ago) by a) using modulated IR (which the pair I referred to does) and b) by use of directional tube on the receiving side (and possibly the sending side too) to reduce the effect of the beam angle. This is part of the point of my project - research as well as implementation.

If you have any helpful advice to share based on your experience in this area I would be grateful.

Thanks

How about using a laser instead of an IR beam?

For me, this is about a chance to do something neat and interesting with my son who has an interest in electronics and programming.

You could use lasers instead of IR LEDs.

Hi.

Thanks for the thought.

I had thought about that as an option. I think that the problems might be a) safety - there may be issues with ensuring that eyesight is protected and b) the issue of visibility in strong sunlight. I'm not sure about b). I had thought of using a laser to ensure the correct alignment of the IR across the gate.

Thanks

Carl

I've already done this.

A 100ma, IR LED modulated at 38Khz will give you about 15 feet of range. With a red, 3V laser (from a disassembled laser pointer) the distance is "much greater"; I only measured about 40 feet and had no reason to go beyond that. You could probably reduce the power of the laser further if you have safety concerns.

I used a TSOP4038 for my target -- note that this IR receiver is different than standard IR receivers used with IR remote controls. With this receiver you can use a simple 555 circuit to modulate the LED whereas IR receivers used with remote control protocols require some funky on/off periods, etc. which you really want to avoid.

Hi.

Sorry, seem to have highjacked astrodads thread!

Chagrin - I was planning on using the pair I linked in reply #4, which are modulated to 38Khz. I've done a little testing and seems to work ok. More work to do in different conditions to prove it though. I only need a range of around 2 metres so modulated IR would seem to be adequate and potentially safer.

I would be interested if you think the basic setup would work as well as your suggestion. I'm an electronics novice, but am very happy to learn (preferably before I commit to something and then it fails!).

Thanks

Pete - don't want to get in a pissing contest.

Caution and sagacity in equal measure.

I'm a qualified timekeeper

I'm a qualified brainsurgeon.

, and the typical error with a novice timer is at least 0.5sec.

OK, I'll bite. What is a "novice timer" and what causes the errors?

I accept the possible limitations of the IR system,
but hope to mitigate [...] by a) using modulated IR

Why will this mitigate the limitations?

by use of directional tube on the receiving side (and possibly the sending side too)

What is a directional tube?

This is part of the point of my project - research as well as implementation.

Ah yes, your project. About that. Which university assigns such a trivial project to "an electronics novice" for a "final Uni project"? Surely not Oxford?

If you have any helpful advice to share based on your experience in this area I would be grateful.

I have been beaten to it, but a small red laser that you can buy at places like Radio Shack will give a beam that has a negligible spread over the distances required by this "project". I'm surprised that a "qualified timekeeper" wouldn't know this.

But why on earth does timing an 8-year old boy (assuming he exists) require such incredible accuracy? One of the arts of being a parent is in creative lying. Use a stopwatch and keep telling him he's doing great.

Thanks

You're welcome.

Pete

The safety issues with lasers can mostly be eliminated by having the arduino control the lasers.
Have the arduino hold each laser on while aiming it to the sensor. Once the lasers are aimed, the lasers would only be on while their sensor is armed. The arduino then turns each laser off when its sensor is triggered.

Darkdragon - thank you. I will look into that, but I am not sure whether that is going to work because the distance of the runs may vary so the timing of the turning on of the laser will have to be carefully controlled. However long the laser would be on it could be a potential danger. I'm assuming that laser light at almost any intensity is unsafe if viewed directly. Any further advice on this appreciated.

Pete - you win! Congratulations.

Thanks

el_supremo:
But why on earth does timing an 8-year old boy (assuming he exists) require such incredible accuracy? One of the arts of being a parent is in creative lying. Use a stopwatch and keep telling him he's doing great.

Pete

You don't know my son. And yes, he's a real person.

He wants to know things like this:

  • How fast am I compared to Julio Jones who ran a 40 yard in 4.39 seconds?
  • Am I as fast as a horse? A dog? A mule?
  • What happens if I wear a sweater instead of a jacket? Am I faster?
  • If I were to run at my top speed can I get to Miami in a week? A month?

He wants to talk all of his speed timings, and those of his friends, and create a competition game he can use at flag football practice. He loves statistics, enjoys tinkering with electronics, and likes computers. And I don't like lying to him.

As a parent, I thought my job was to inspire him to greatness and goodness; not to give him a pep talk.

CarlJP...it's okay. I'm learning a lot from this discussion. I think I'm going to give it a go with the lasers since they would have a much higher cool factor with him.

Great. Please keep us posted. Sounds like a great kid. Good luck to you both.