Interfacing 5 Pots with a PC

T

themadscientist

Guest
I need to figure out how to monitor the position of 5 seperate pots using a
PC. I'm a software, not a hardware guy (but trying to learn). I found the
ADR101 from Ontrak Control Systems that will allow me to monitor two pots,
but it costs $100 + $13 for the wallwart.

Can't this be done simpler than using a STAMP or PIC? Anyone aware of
circuits, diagrams, or other info that I could take a look at?

Thanks,
Jerry
 
In article <Xns94B7B24333811nonenonecom@24.93.43.121>,
themadscientist <none@none.com> wrote:
-I need to figure out how to monitor the position of 5 seperate pots using a
-PC. I'm a software, not a hardware guy (but trying to learn). I found the
-ADR101 from Ontrak Control Systems that will allow me to monitor two pots,
-but it costs $100 + $13 for the wallwart.

OUCH! That's criminal.

-
-Can't this be done simpler than using a STAMP or PIC?

Stamp: probably.
PIC: definitely

And neither will cost you $113 bucks.

- Anyone aware of
-circuits, diagrams, or other info that I could take a look at?

Nothing off the top of my head. But here's a back of the envelope design.
I'm working under the presumption that this isn't a high speed application.

The design consists of three parts:

1) Pot input: pots of course have the problem that the impeadnace is all over
the place due to the changing resistance. PIC A/D inputs prefer a known
impeadance. So I'd use a rail to rail opamp voltage follower circuit like
figure 2 on this page http://www.colomar.com/Shavano/intro_opamp.html
With a quad opamp like a LM324 you can drive 4 pots, so unfortunately you'd
need two of them.

2) PIC. The ideal choice of part is the 16F88. Randy Jones of glitchbuster.com
has them for $3.19 each with $1.85 shipping. Can't be beat. There are three
reasons why this is the ideal choice:

A) It has built in A/D which you connected the opamp outputs of part 1
above (I'd use a 5k series resistor so as not to overdrive the ADC)
B) It has built in hardware serial to interface with the PC.
C) It has a built in osciallator that's precise enough so UART probably
works OK at room temp, so no additional parts are required. The datasheet
gives some examples in chapter 11.

3) Serial interface. Get a MAX232 or equivalent. You'll thank yourself later.

So wire the pots to the opamps, connect the opamps to the ADC via 5K resistors,
connect the UART to the MAX232, then connect the max232 to a PC serial port.
Power the whole mess from a USB port and call it a day.

Take a look at JAL or XCSB for programming. These are two languages I talk
about on my PIC languages page: http://www.finitesite.com/d3jsys/languages.html
and you can also find my trivial PIC programmer hardware there too.

BAJ
 
Subject: Interfacing 5 Pots with a PC
From: themadscientist none@none.com
Date: 3/25/2004 5:18 PM Central Standard Time
Message-id: <Xns94B7B24333811nonenonecom@24.93.43.121

I need to figure out how to monitor the position of 5 seperate pots using a
PC. I'm a software, not a hardware guy (but trying to learn). I found the
ADR101 from Ontrak Control Systems that will allow me to monitor two pots,
but it costs $100 + $13 for the wallwart.

Can't this be done simpler than using a STAMP or PIC? Anyone aware of
circuits, diagrams, or other info that I could take a look at?

Thanks,
Jerry
Click to expand...

How about $39.95 for the whole kit -- all you'll have to do is solder some
thru-hole components on a small board, add a 9VDC wall wart, and you're good to
go.

Al Williams' GP-3 is PIC-based, has 5 10-bit A-D inputs, interfaces with a PC
through the serial port, and already has drivers for C, Java, VB, you name it.
You even get a driver to import directly to Excel. And no, I don't work for
them. The only other thing you need is a computer and a DB-9 RS-232 cable.

http://www.al-williams.com/gp3.htm

Good luck
Chris
 
Wow, thanks for the help, Byron. I wish designing a circuit was as easy
for me as it is for you. Your post was so informative that I'm keeping
it as a future project to work on when my electronics knowledge is a
little more advanced. I think jumping into PIC programming will be like
running before I can walk.

Also, have you used "digital" potentiometers/encoders (I'm not quite sure
what the correct term is)? From what I've researched, they produce
square waves automagically, which to me says that an A/D conversion isn't
necessary. Couldn't these be connected directly to the parallel port
input pins?

Thanks for the help!




byron@cc.gatech.edu (Byron A Jeff) wrote in
news:c403gj$884@cleon.cc.gatech.edu:

In article <Xns94B7B24333811nonenonecom@24.93.43.121>,
themadscientist <none@none.com> wrote:
-I need to figure out how to monitor the position of 5 seperate pots
using a -PC. I'm a software, not a hardware guy (but trying to
learn). I found the -ADR101 from Ontrak Control Systems that will
allow me to monitor two pots, -but it costs $100 + $13 for the
wallwart.

OUCH! That's criminal.

-
-Can't this be done simpler than using a STAMP or PIC?

Stamp: probably.
PIC: definitely

And neither will cost you $113 bucks.

- Anyone aware of
-circuits, diagrams, or other info that I could take a look at?

Nothing off the top of my head. But here's a back of the envelope
design. I'm working under the presumption that this isn't a high speed
application.

The design consists of three parts:

1) Pot input: pots of course have the problem that the impeadnace is
all over
the place due to the changing resistance. PIC A/D inputs prefer a
known impeadance. So I'd use a rail to rail opamp voltage follower
circuit like figure 2 on this page
http://www.colomar.com/Shavano/intro_opamp.html With a quad opamp
like a LM324 you can drive 4 pots, so unfortunately you'd need two
of them.

2) PIC. The ideal choice of part is the 16F88. Randy Jones of
glitchbuster.com
has them for $3.19 each with $1.85 shipping. Can't be beat. There
are three reasons why this is the ideal choice:

A) It has built in A/D which you connected the opamp outputs of
part 1
above (I'd use a 5k series resistor so as not to overdrive the
ADC)
B) It has built in hardware serial to interface with the PC.
C) It has a built in osciallator that's precise enough so UART
probably
works OK at room temp, so no additional parts are required. The
datasheet gives some examples in chapter 11.

3) Serial interface. Get a MAX232 or equivalent. You'll thank yourself
later.

So wire the pots to the opamps, connect the opamps to the ADC via 5K
resistors, connect the UART to the MAX232, then connect the max232 to
a PC serial port. Power the whole mess from a USB port and call it a
day.

Take a look at JAL or XCSB for programming. These are two languages I
talk about on my PIC languages page:
http://www.finitesite.com/d3jsys/languages.html and you can also find
my trivial PIC programmer hardware there too.

BAJ
Click to expand...
 
That's perfect, thanks!



How about $39.95 for the whole kit -- all you'll have to do is solder
some thru-hole components on a small board, add a 9VDC wall wart, and
you're good to go.

Al Williams' GP-3 is PIC-based, has 5 10-bit A-D inputs, interfaces
with a PC through the serial port, and already has drivers for C,
Java, VB, you name it. You even get a driver to import directly to
Excel. And no, I don't work for them. The only other thing you need
is a computer and a DB-9 RS-232 cable.

http://www.al-williams.com/gp3.htm

Good luck
Chris
Click to expand...
 
CFoley1064 wrote:

Subject: Interfacing 5 Pots with a PC
From: themadscientist none@none.com
Date: 3/25/2004 5:18 PM Central Standard Time
Message-id: <Xns94B7B24333811nonenonecom@24.93.43.121

I need to figure out how to monitor the position of 5 seperate pots using a
PC. I'm a software, not a hardware guy (but trying to learn). I found the
ADR101 from Ontrak Control Systems that will allow me to monitor two pots,
but it costs $100 + $13 for the wallwart.

Can't this be done simpler than using a STAMP or PIC? Anyone aware of
circuits, diagrams, or other info that I could take a look at?

Thanks,
Jerry
Click to expand...

How about $39.95 for the whole kit -- all you'll have to do is solder some
thru-hole components on a small board, add a 9VDC wall wart, and you're good to
go.

Al Williams' GP-3 is PIC-based, has 5 10-bit A-D inputs, interfaces with a PC
through the serial port, and already has drivers for C, Java, VB, you name it.
You even get a driver to import directly to Excel. And no, I don't work for
them. The only other thing you need is a computer and a DB-9 RS-232 cable.

http://www.al-williams.com/gp3.htm
Click to expand...
You don't even need to do that. There are two pots on each joystick,
and there are two joysticks per game port. You can use another game
port adapter for the additional 5th pot. I believe each pot is 100k to
150k but other values should work.


Good luck
Chris
Click to expand...
 
In article <Xns94B8548FDD60Cnonenonecom@24.93.43.121>,
themadscientist <none@none.com> wrote:
-Wow, thanks for the help, Byron. I wish designing a circuit was as easy
-for me as it is for you. Your post was so informative that I'm keeping
-it as a future project to work on when my electronics knowledge is a
-little more advanced. I think jumping into PIC programming will be like
-running before I can walk.

There are some (Are you out ther Steve?) that would agree with you
wholeheartedly. However I'd like to give a little of my insight. It's my
belief that no matter if you use transistors, opamps/comparators, logic
chips, or microcontrollers, in the end it becomes a process of programming. I
can pretty much guarantee that before this thread is over, someone is going
to suggest using 5 555 timers to generate a freqency based on value of the
pot.

But the bottom line is that every design is going to require some measure of
programming. My vote is to program in software as much as possible. Here's why:

1) You only have to build/learn the toolchain once. What you learn programming
this project can often be applied in some form to the next project.
2) It gives you control of logic, opamp/comparators, timers and the like
without having to physically wire them.
3) Changes and or additions to the functionality of the project can often be
realized only be changing some code.

While clearly there will be more skillset gaps by limiting the hardware used
and while clearly sometimes specialized hardware is required (like the opamps
voltage followers for impeadance matching that I threw in) by using a
microcontroller as a jellybean programmable element, designs can be done
quicker, cleaner, and faster.

-
-Also, have you used "digital" potentiometers/encoders (I'm not quite sure
-what the correct term is)?

Quadrature encoders.

- From what I've researched, they produce
-square waves automagically, which to me says that an A/D conversion isn't
-necessary.

Correct. However there are a couple of issues.

- Couldn't these be connected directly to the parallel port input pins?

Yes. But you're pushing the limit with 5 inputs. Also with Qencoders there's
no absolute measure of value. A pot whose terminals are tied between 0 and +5
can be set precisely to 3.17V and will register that as long as it's not
moved. But Qencoders basically only have "Count left" and "Count right"
commands which means that your software someone is going to have to track
the values.

It's one of the reasons I prefer the pot/switch input interface to the
Qencoder/switch interface, though admittedly both have issues.

But again in this case, it may be better to have a microcontroller read the
Qencoders, track the values, and transmit them to the PC.

-
-Thanks for the help!

No problem. I wouldn't abandon the microcontroller route just yet if I were
you.

BAJ
[snipped]
 
Byron A Jeff wrote:
In article <Xns94B8548FDD60Cnonenonecom@24.93.43.121>,
themadscientist <none@none.com> wrote:
-Wow, thanks for the help, Byron. I wish designing a circuit was as easy
-for me as it is for you. Your post was so informative that I'm keeping
-it as a future project to work on when my electronics knowledge is a
-little more advanced. I think jumping into PIC programming will be like
-running before I can walk.

There are some (Are you out ther Steve?) that would agree with you
wholeheartedly.
------------------
Click to expand...
More like calling a cab when you find you can't ride your bicycle
and want to just get there without really learning how!!


However I'd like to give a little of my insight. It's my
belief that no matter if you use transistors, opamps/comparators, logic
chips, or microcontrollers, in the end it becomes a process of programming. I
can pretty much guarantee that before this thread is over, someone is going
to suggest using 5 555 timers to generate a freqency based on value of the
pot.
---------------------------
Click to expand...
That's how the PC joystick works!


But the bottom line is that every design is going to require some measure of
programming. My vote is to program in software as much as possible. Here's why:

1) You only have to build/learn the toolchain once. What you learn programming
this project can often be applied in some form to the next project.
2) It gives you control of logic, opamp/comparators, timers and the like
without having to physically wire them.
3) Changes and or additions to the functionality of the project can often be
realized only be changing some code.

While clearly there will be more skillset gaps by limiting the hardware used
and while clearly sometimes specialized hardware is required (like the opamps
voltage followers for impeadance matching that I threw in) by using a
microcontroller as a jellybean programmable element, designs can be done
quicker, cleaner, and faster.

-
-Also, have you used "digital" potentiometers/encoders (I'm not quite sure
-what the correct term is)?

Quadrature encoders.

- From what I've researched, they produce
-square waves automagically, which to me says that an A/D conversion isn't
-necessary.

Correct. However there are a couple of issues.

- Couldn't these be connected directly to the parallel port input pins?

Yes. But you're pushing the limit with 5 inputs. Also with Qencoders there's
no absolute measure of value. A pot whose terminals are tied between 0 and +5
can be set precisely to 3.17V and will register that as long as it's not
moved. But Qencoders basically only have "Count left" and "Count right"
commands which means that your software someone is going to have to track
the values.
--------------------------------
Click to expand...
You can use external counters that are read into the LPT, and the
5 inputs can be multiplexed into a large number of effective byte
inputs.


It's one of the reasons I prefer the pot/switch input interface to the
Qencoder/switch interface, though admittedly both have issues.

But again in this case, it may be better to have a microcontroller read the
Qencoders, track the values, and transmit them to the PC.

-
-Thanks for the help!

No problem. I wouldn't abandon the microcontroller route just yet if I were
you.

BAJ
[snipped]
-------------------------
Click to expand...
Absolutely, but start with electronics and work toward uC's, don't
try to avoid "the work", because you will need it to use uC's to
be effective.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
Byron A Jeff wrote:

In article <Xns94B8548FDD60Cnonenonecom@24.93.43.121>,
themadscientist <none@none.com> wrote:
-Wow, thanks for the help, Byron. I wish designing a circuit was as easy
-for me as it is for you. Your post was so informative that I'm keeping
-it as a future project to work on when my electronics knowledge is a
-little more advanced. I think jumping into PIC programming will be like
-running before I can walk.

There are some (Are you out ther Steve?) that would agree with you
wholeheartedly.
------------------
More like calling a cab when you find you can't ride your bicycle
and want to just get there without really learning how!!


However I'd like to give a little of my insight. It's my
belief that no matter if you use transistors, opamps/comparators, logic
chips, or microcontrollers, in the end it becomes a process of programming. I
can pretty much guarantee that before this thread is over, someone is going
to suggest using 5 555 timers to generate a freqency based on value of the
pot.
---------------------------
That's how the PC joystick works!
Click to expand...
Yes, that is how a PC joystick works, but they usually have a single
IC 558 which is equivalent to 4 555's....These are very hard to find
and near the point of extinction.

For less than $2 you can use another single IC that could handle up to
Six pots. The 74HC14 (Note: CMOS version required C,AC,HC,HCT) is
a HEX-Schmidt trigger inverter. Simply connect the POT (middle
terminal and one outer terminal) across the INput (A) terminal and the
OUTput (Y) terminal. (Note: use a bias resistor of at least 1K in
series with the POT) Tie each INput (A) to GND via a 1uF-10uF
capacitor (Note: capacitor polarity is important; negative to GND and
positive to the input). Since you are using only 5 POTS, you don't
need to multiplex any of the outputs from the 74HC14, simply connect
to the 5 available inputs on your parallel port. Don't forget to tie
any unused inputs on the 74HC14 to GND or +5V (one or the other).
With this approach, the 74HC14 could be powered from the parallel
port. Use at least a 100uF Capacitor across the +5V and GND of the
74HC14 IC.

In software simply 'count' the number of pulses within a given amount
of time to determine the POT value(s). Depending on your programming
skills this could be manipulated one POT at a time, or there are
clever programming techniques that would allow you to sample all of
the POTS at once.

(snip)

Beau Schwabe
IC Mask Designer - National Semiconductor Corporation
polygon_man@highstream.net
 
Beau,

So the 74HC14 would work right out of the box? It's not the programming
I'm afraid of, I simply don't have a PIC programmer.

I've done parallel port programming before where I have a relay that, when
power is applied from a motion detector, it shorts two pins on the port and
my software begins recording video from a camera.

My electronics knowledge is very rudimentary, but I am learning. I've been
using the lessons from www.twysted-pair.com, so I'm getting there. (My
brain has turned to mush from all the equations) I really appreciate the
help.

Thanks



Yes, that is how a PC joystick works, but they usually have a single
IC 558 which is equivalent to 4 555's....These are very hard to find
and near the point of extinction.

For less than $2 you can use another single IC that could handle up to
Six pots. The 74HC14 (Note: CMOS version required C,AC,HC,HCT) is
a HEX-Schmidt trigger inverter. Simply connect the POT (middle
terminal and one outer terminal) across the INput (A) terminal and the
OUTput (Y) terminal. (Note: use a bias resistor of at least 1K in
series with the POT) Tie each INput (A) to GND via a 1uF-10uF
capacitor (Note: capacitor polarity is important; negative to GND and
positive to the input). Since you are using only 5 POTS, you don't
need to multiplex any of the outputs from the 74HC14, simply connect
to the 5 available inputs on your parallel port. Don't forget to tie
any unused inputs on the 74HC14 to GND or +5V (one or the other).
With this approach, the 74HC14 could be powered from the parallel
port. Use at least a 100uF Capacitor across the +5V and GND of the
74HC14 IC.

In software simply 'count' the number of pulses within a given amount
of time to determine the POT value(s). Depending on your programming
skills this could be manipulated one POT at a time, or there are
clever programming techniques that would allow you to sample all of
the POTS at once.

(snip)

Beau Schwabe
IC Mask Designer - National Semiconductor Corporation
polygon_man@highstream.net
Click to expand...
 
themadscientist wrote:
Beau,

So the 74HC14 would work right out of the box? It's not the programming
I'm afraid of, I simply don't have a PIC programmer.
-------------------
Click to expand...
Well you simply should NEVER BUY one, you know, make one, there
are loads of projects online.


I've done parallel port programming before where I have a relay that, when
power is applied from a motion detector, it shorts two pins on the port and
my software begins recording video from a camera.
---------------------
Click to expand...
Then you're on your way, you can build a simple programmer, but you
might want to first do some more simple experiments, and program
EPROMs or EEPROMs or such.


My electronics knowledge is very rudimentary, but I am learning. I've been
using the lessons from www.twysted-pair.com, so I'm getting there. (My
brain has turned to mush from all the equations) I really appreciate the
help.

Thanks
-----------------
Click to expand...
Most equations are not as necessary as the author might have you
think.


Yes, that is how a PC joystick works, but they usually have a single
IC 558 which is equivalent to 4 555's....These are very hard to find
and near the point of extinction.

For less than $2 you can use another single IC that could handle up to
Six pots. The 74HC14 (Note: CMOS version required C,AC,HC,HCT) is
a HEX-Schmidt trigger inverter. Simply connect the POT (middle
terminal and one outer terminal) across the INput (A) terminal and the
OUTput (Y) terminal. (Note: use a bias resistor of at least 1K in
series with the POT) Tie each INput (A) to GND via a 1uF-10uF
capacitor (Note: capacitor polarity is important; negative to GND and
positive to the input). Since you are using only 5 POTS, you don't
need to multiplex any of the outputs from the 74HC14, simply connect
to the 5 available inputs on your parallel port. Don't forget to tie
any unused inputs on the 74HC14 to GND or +5V (one or the other).
With this approach, the 74HC14 could be powered from the parallel
port. Use at least a 100uF Capacitor across the +5V and GND of the
74HC14 IC.

In software simply 'count' the number of pulses within a given amount
of time to determine the POT value(s). Depending on your programming
skills this could be manipulated one POT at a time, or there are
clever programming techniques that would allow you to sample all of
the POTS at once.

(snip)

Beau Schwabe
IC Mask Designer - National Semiconductor Corporation
polygon_man@highstream.net

-------------------------
Click to expand...
Simple.

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public
 
On Sat, 27 Mar 2004 20:13:15 GMT, themadscientist
<askdfjals@askdfjhasdofansdf.com> wrote:

Beau,

So the 74HC14 would work right out of the box? It's not the programming
I'm afraid of, I simply don't have a PIC programmer.
Click to expand...
Yes, the 74HC14 would work right out of the box...and you don't need a
PIC programmer.

Schematic:
http://www.angelfire.com/wizard/y2kbc/Schematics/5POT2PC.gif

Depending on the value and range of your POTS, you might need to
experiment with different series resistor and or capacitor values.
Referring to the Datasheet below, on page 17 there is a formula for
calculating the frequency based upon the type of 74xx14 used and
the R and C values used.

Datasheet:
http://www.semiconductors.philips.com/acrobat/datasheets/74HC_HCT14_3.pdf


I've done parallel port programming before where I have a relay that, when
power is applied from a motion detector, it shorts two pins on the port and
my software begins recording video from a camera.

My electronics knowledge is very rudimentary, but I am learning. I've been
using the lessons from www.twysted-pair.com, so I'm getting there. (My
brain has turned to mush from all the equations) I really appreciate the
help.

Thanks



Yes, that is how a PC joystick works, but they usually have a single
IC 558 which is equivalent to 4 555's....These are very hard to find
and near the point of extinction.

For less than $2 you can use another single IC that could handle up to
Six pots. The 74HC14 (Note: CMOS version required C,AC,HC,HCT) is
a HEX-Schmidt trigger inverter. Simply connect the POT (middle
terminal and one outer terminal) across the INput (A) terminal and the
OUTput (Y) terminal. (Note: use a bias resistor of at least 1K in
series with the POT) Tie each INput (A) to GND via a 1uF-10uF
capacitor (Note: capacitor polarity is important; negative to GND and
positive to the input). Since you are using only 5 POTS, you don't
need to multiplex any of the outputs from the 74HC14, simply connect
to the 5 available inputs on your parallel port. Don't forget to tie
any unused inputs on the 74HC14 to GND or +5V (one or the other).
With this approach, the 74HC14 could be powered from the parallel
port. Use at least a 100uF Capacitor across the +5V and GND of the
74HC14 IC.

In software simply 'count' the number of pulses within a given amount
of time to determine the POT value(s). Depending on your programming
skills this could be manipulated one POT at a time, or there are
clever programming techniques that would allow you to sample all of
the POTS at once.

(snip)
Click to expand...
Beau Schwabe
IC Mask Designer - National Semiconductor Corporation
polygon_man@highstream.net
 
Is there a certain pot you suggest using with this chip?

Thanks again, you've been extremely helpful.


On Sat, 27 Mar 2004 20:13:15 GMT, themadscientist
askdfjals@askdfjhasdofansdf.com> wrote:

Beau,

So the 74HC14 would work right out of the box? It's not the
programming I'm afraid of, I simply don't have a PIC programmer.

Yes, the 74HC14 would work right out of the box...and you don't need a
PIC programmer.

Schematic:
http://www.angelfire.com/wizard/y2kbc/Schematics/5POT2PC.gif

Depending on the value and range of your POTS, you might need to
experiment with different series resistor and or capacitor values.
Referring to the Datasheet below, on page 17 there is a formula for
calculating the frequency based upon the type of 74xx14 used and
the R and C values used.

Datasheet:
http://www.semiconductors.philips.com/acrobat/datasheets/74HC_HCT14_3.p
df
Click to expand...
 
Is there a certain pot you suggest using with this chip?

Thanks again, you've been extremely helpful.
Click to expand...
Other than a linear taper POT, there is no real issue. Not that they
would not work, but you might not get the optimal range with a log or
audio taper POT that you desire. What I referred to earlier is that
you might need to experiment a bit with various resistor and capacitor
values to get the frequency range just right to interpret a meaningful
value in software. Find your corners (limitations) for minimum and
maximum values and figure in a certain amount of padding so that the
POT stays within this limit.

Beau Schwabe
IC Mask Designer - National Semiconductor Corporation
polygon_man@highstream.net
 
I'm just gonna toss this out there... I've never personally done it, but it
seems obvious to me:

How about the gameport?

http://www.ctips.com/game.html 3/4 of the way down includes the pinout
diagram, which seems to show that it can support 4 Pots.. I have no idea
what you're using this for, but if you can modify whatever it is for only 4
pots, then you might be able to save yourself a lot of money/work if you can
find a way to use the gameport. Or just pop in a second old $5 soundcard
that has a gameport on it... probably add as many as you want! (I have 2 in
my PC).

If you wire it to the gameport, you'll also have a really nice calibration
program already written for you (control panel/gaming devices/calibrate).
And you'll be able to read the position of all your pots probably through
directX or any other ways.. you're the programmer :)

Mike
http://mikebeauchamp.com




"themadscientist" <none@none.com> wrote in message
news:Xns94B7B24333811nonenonecom@24.93.43.121...
I need to figure out how to monitor the position of 5 seperate pots using
a
PC. I'm a software, not a hardware guy (but trying to learn). I found
the
ADR101 from Ontrak Control Systems that will allow me to monitor two pots,
but it costs $100 + $13 for the wallwart.

Can't this be done simpler than using a STAMP or PIC? Anyone aware of
circuits, diagrams, or other info that I could take a look at?

Thanks,
Jerry
Click to expand...
 
This is going to be used on a Mini-ITX motherboard, which has no gameport.
Good idea, though.



"Mike Beauchamp" <newsgroups@mikebeauchamp.com> wrote in
news:c47a1e0dp@enews3.newsguy.com:

I'm just gonna toss this out there... I've never personally done it,
but it seems obvious to me:

How about the gameport?

http://www.ctips.com/game.html 3/4 of the way down includes the pinout
diagram, which seems to show that it can support 4 Pots.. I have no
idea what you're using this for, but if you can modify whatever it is
for only 4 pots, then you might be able to save yourself a lot of
money/work if you can find a way to use the gameport. Or just pop in a
second old $5 soundcard that has a gameport on it... probably add as
many as you want! (I have 2 in my PC).

If you wire it to the gameport, you'll also have a really nice
calibration program already written for you (control panel/gaming
devices/calibrate). And you'll be able to read the position of all
your pots probably through directX or any other ways.. you're the
programmer :)

Mike
http://mikebeauchamp.com
Click to expand...
 
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