Step 7: Solder the Serial Port Connector

Now attach the smaller gauge wires to the large wires and solder them to the serial port connector. You'll need to solder the wires to pins 4 and 6. Since we're just completing a circuit, it doesn't matter which wire goes to which pin just make sure you get 4 and 6. The connector you get will be labeled with the pin numbers and you can also see which pins you need to attach to below.

Pin 4 on a serial port is also known as "DTR" or Data Terminal Ready. Pin 6 is also known as "DSR" or Data Set Ready. When we write our program we'll be able to set DSR to +5V and check if DTR is +5V. As a result we will be able to determine whether or not the magnet is over the switch. And if we check very quickly then we'll be able to figure out how often and how quickly the wheel turns to determine both number of rotations and speed of each rotation.
Aaaahhhh :( The website doesn't exist.
Or you could measure the outside with a fabric (cloth) tape (ruler).
I am making something similar to this for my pet hedgehog. Instead of hooking it up to a computer, I'm going to use a calculator as described in this instructable:<br><br>http://www.instructables.com/id/Versatile-and-Low-Cost-Digital-Counter/?ALLSTEPS
no matter how thick your wire, do not let your hamster anywhere near it. that's very important.
could the magnets kill your hamster
No, magnets will not hurt a hamster. The fields used for MRI use magnetic fields that are much larger, and are used routinely in hospitals.
that makes me wonder about this project... hmm...
Ummm...can&nbsp; you upload it somewhere else?<br />
like my hamster?
Looks like its ready to run!
shes not exactly the sort of hamster that will sit down and watch tv so ye she enjoys running
Oh man...if I ever get a hamster, I'm making one of these.
Does the python program run all the time on your comuter in the background? or do you start it at night and stop it in the morning? Also, won't writing a file every revolution wear down the harddisk? I've seen hamsters run in wheels and they pretty darn fast...
Yup, it runs continuously on my computer just in case she runs a little during the day as well. This won't really wear down a hard disk any faster than normal. While hamsters look fast to you and I, there are programs that write data much more quickly than the hamster can run.
it,s good
You could also just buy a bike spedomiter and put it on the hamster wheel. You can get cheap ones for about $10. Nice instructable, though.
thats true too, although it may not work on such a small weel :o
You can usually just set them to the MM in width, and Mine can go down to 1 MM. THat would be a small wheel.
My daughter and I got a bike speedometer to work with her hamster wheel without much trouble. The speedometer was set up so you could calibrate it to any wheel diameter using a little table. We were astounded to find that our hamster was running 5 to 8 miles a night!! At first we thought we had made a mistake, but we found a few people on the web with similar results. It worked great and was really easy and fun- the only thing we would change is that we we would add some kind of protection to the wires leading from the wheel to the speedometer - the hamster eventually got bored and chewed through.
more... My post made it sound like our hamster died from chewing through the wires. It was fine. The wires don't carry much current; just a little signal from the wheel.
small question: what speedometer did you use? i am trying to find a good one for my hamster wheel.
It's been a while, so I'm not exactly sure. Judging from the pictures and prices of the different speedometer/odometers on Amazon, I'm pretty sure it was a "Bell SpinFit Calorie Bike Speedometer", which costs around $15.00.
oh sweet thanks so much :)
Cool! I would do this with my guinea pig but she runs about 2 meters a week, so Im not so sure that it would be worth it. 8 miles! Thats a lot! Farther than I run... A lot farther.
lol, probibly not faster... the hamster has all night to do it :P you may olny have a while :)
True, but still...
lol :) pwnt me eh? :D
good i thought he died lol
lol, okay :P u might be right, idk much about it ;)
Me neither. MY guinea pig is way too lazy to use a wheel...
thanks lol :)
i see a dead hamster next to a chewed up wire.... uh ohs not good.
The wires are actually have incredibly little power going through them, only 5 V and about 10mA. That is way to low to cause any harm to hamster or person.
15 mA kills a human... -PKT
The key here is voltage. If the current cannot flow then it is harmless. If you touch any of the ports on the back of your computer 5v is what you'r touching. That's what's going through these wires.
Great idea and nice job presenting!
prettty difficult to me... nice project. i wonder how far my hamster can run
Can you just give me the compiled EXE instead of me having to do it from scratch?
So this can determine the RPM's of a spinning object? I think i just sparked an idea...
This is so cool - I really want to do this but am failing when it comes to the writing programme bit... I know its cheating but does anyone know where I can download these? or get a step by step how to set this bit up? Please help....
Very cool ible. You may want to consider counter-weighting the magnets... to Lizzie, the difference could be enormous (imagine running over a thousand little hills).
That's a good point. Very unscientifically we figured it wasn't too much of an issue since the friction inherent in the wheel and caused by the bedding she stuffs under it meant the magnet doesn't cause the wheel to turn on its own. However, I wonder if there's better way to measure this as well as how much this added friction affects how far she can run.
I wonder if she purposely stuffs the bedding under the wheel to increase the turning resistance for more exercise, the equivalent of running up a steady incline versus level ground. ??<br/>The off-balance caused by the magnet would still have an effect, tho disguised by the friction caused by the bedding, resulting in a likeness of running <em>up</em> a thousand little hills. Now, if only there was a way to measure the effect of this exercise. Sounds like a topic for another Ible.<br/>
This is a great project - really easy to do! I managed to put it all together and adjust the python file etc pretty easily!! I thought about doing the cycle computer, but it just isnt as cool as having it logged and uploading to the web automatically!<br/><br/>you can see my set up here:<br/><br/><a rel="nofollow" href="http://hamsterhike.co.uk/blog/?page_id=63">Hamster Hike</a><br/><br/>i've turned this into a website too with the blessing of the hamster across america guys!<br/>
Wodent Wheels makes (or used to make) a Wodometer to attach to their wheels
SWEET! have you ever calculated the top speed?
Yup just went through the data right now. Looks like her top speed is somewhere around 2.5 mph and she prefers to run at about 1.75 mph. Interestingly the graph how much time she spends at each speed is a pretty neat curve. <a rel="nofollow" href="http://www.int8.com/SpeedDistribution.jpg">Here's</a> a bigger version of the graph below.<br/><br/>
looks like a gaussian distribution :]
This is an awesome graph!
um good.,but i have a dog,so i made a insructable. go to my profile and find the simular instructable.

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