Turn a PC mouse into a Speedo

ph2t · Post by **ph2t** » Sun Jul 13, 2003 6:59 am

Just found this circuit HERE. I've a hall effect sensor now. Hopefully its just building the circuit and a few bits of interface electronics and we should be sweet.

ph2t.

Ace_B_Pimpn · Post by **Ace_B_Pimpn** » Tue Jul 15, 2003 10:33 pm

nox, why don't you make this prog into a full screen.
You know the screen you have to us alt f4 to get out of. Then we wouldn't have to hold the mouse button

ph2t · Post by **ph2t** » Tue Jul 15, 2003 10:54 pm

Ace, the scope of the program has changed a shitload since we first started workin on it. We are no longer using the ps2 port / mouse electronics 'cause it is inadequete for the speeds/rpm's involved.(see earlier discussions in this thread). I'm sure the program has changed (and will continue to change) as we develop this shiat!

Nox, I got a call from a supplier who will be shipping me the parts today so I *should* have some working hardware-wise by the weekend. Could you post the proggie that reads Data 0 (pin 2) on the parallel port so I could begin testing. Thanks man.

ph2t.

noxorc · Post by **noxorc** » Wed Jul 16, 2003 5:48 am

I will post the latest version, as soon as I can (before the weekend).

-nox

noxorc · Post by **noxorc** » Wed Jul 16, 2003 5:50 am

Oh BTW Ph2t,

that link you provided, doesn't go anywhere.

-nox

ph2t · Post by **ph2t** » Wed Jul 16, 2003 7:27 am

noxorc wrote:Oh BTW Ph2t,

that link you provided, doesn't go anywhere.

-nox

Just saw that, doh. I guess there is no site called HERE on the net.

noxorc · Post by **noxorc** » Wed Jul 16, 2003 7:34 am

ph2t wrote:
noxorc wrote:Oh BTW Ph2t,

that link you provided, doesn't go anywhere.

-nox
Just saw that, doh. I guess there is no site called HERE on the net.

yea, there is, you got it over there. I mean over HERE.

ph2t · Post by **ph2t** » Wed Jul 16, 2003 7:39 am

lol! good one dickhead!

Seriously though, I bustin out the dremel right now. Will have some pics soon of a test setup......

ph2t.

ph2t · Post by **ph2t** » Wed Jul 16, 2003 8:14 am

Pretty much took the base of an old MS mouse.

And cut out the encoder wheel setup.

I will put the hall effect sensor near the wheel and put a small bit of metal on the circumference of the encoder wheel. This metal will trigger the hall effect sensor everytime it rotates past it.

ph2t.
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Ace_B_Pimpn · Post by **Ace_B_Pimpn** » Wed Jul 16, 2003 11:28 am

i just went to office depot and got a mouse 4 a buck. My dremal isdone charging, so i have the mouse to my self

noxorc · Post by **noxorc** » Wed Jul 16, 2003 8:41 pm

Ph2t,

digital logically speaking:
how does this thing you got work? can you send me some info.
How are you going to tickle data line 0? at what rate?
or at what rate should I sample at?

from my point of view. I can read the data lines. Once or within a read loop.
I would assume I going to watch it tickle back and forth (0,1).

-nox

ph2t · Post by **ph2t** » Wed Jul 16, 2003 11:32 pm

Dude, the circuit is still sorta in my head but it's based around a hall effect device. These devices are very fast and are commonly used in tachos and speed monitors for many different applications.

It goes a little somthin' like this....

The hall effect device is placed near the encoder disc. Attached to the encoder disc is a piece of metal (or some fridge magnet material, yet to decide...). When the BCG is placed on the encoder disc and started the disc rotates and the metal crosses the face of the hall effect sensor.

When the hall effect sensor finds a magnetic field, it outputs a voltage depending on the strength of this field. This varies from sensor to sensor. Some hall devices put out a simple logical "1", others scale the voltage in relation to the magnetic field. Bottom line is that stuff happens when the magnet goes past the hall sensor. It is this trigger I want to capture and put to the parallel port which your software will decode/measure.

As to the rate this data will be triggered at will vary. I can put a divide-by-10 circuit in before the pulse gets to the parallel port to slow it down, your software would need to account for this. Don't code this yet, it's just an example. If you could poll the parallel port as quickly as possible that would be great (assembly anyone?). I'll put the circuit together once I get the parts (should be today) and let you know what my real-world results are.

You're correct about the trickle (0,1) part. Once cycle would be 0,1. Two would be 0,1,0,1, and so on.....

More to come.....

ph2t.

noxorc · Post by **noxorc** » Thu Jul 17, 2003 6:00 am

ph2t wrote:If you could poll the parallel port as quickly as possible that would be great (assembly anyone?). I'll put the circuit together once I get the parts (should be today) and let you know what my real-world results are. ph2t.

My DLL is written in C to read the port. I don't think assembly is going to be any faster. My routine is a very low level functionality call.
Most of the code is to get around Windows C2 complient backdoor entry points.

I'll whip together a ripping loop to read data line 1 and post the version.
that way, when your ready. You'll know, your tickling the data line.

-nox

ph2t · Post by **ph2t** » Thu Jul 17, 2003 5:54 pm

Good stuff man. No movement on the decoder circuit yet, was out all last night. Will post when done. Btw, do you ever sleep nox? lol!

ph2t.

noxorc · Post by **noxorc** » Thu Jul 17, 2003 6:36 pm

ph2t wrote:Good stuff man. No movement on the decoder circuit yet, was out all last night. Will post when done. Btw, do you ever sleep nox? lol!

ph2t.

Sleep? I'm like cabo...a robot...I'm not really a human.
Any processor can type and act like a homie!

-nox

I got bugs, and I smoke them out.