I know that such chips are commercially available. Analog devices or
Dallas semi has them. Don't know if this is the info ou are looking
for. I haven't used them.
--- In basicstamps@y..., "theborderlinecrew" <theborderlinecrew@y...>
wrote:
> Anyone have a listing for such a project?
There is a chapter in Matt Gilliland's book, the Microprocessor Cookbook, on
digital pots. It includes code.
I have used the DS1267 and the DS1804. The 1804 is easier and more intuitive to
work with, but it takes more code
to control the wiper. It seems to me the 1267 is faster to respond, but I am
not able to measure this.
Differences in specs include, in addition to the resistance element, the number
of positions on the wiper. A high
resolution pot like the the 1267 offers 255 increments. The 1804 has 100.
If you are working on a prototype I understand, from other correspondence on
this group, you may be able to get
samples of these chips at the DS site. I think the address is www.dalsemi.com
What do you want to do with the digital pot?
Best, Michael
theborderlinecrew wrote:
> Anyone have a listing for such a project?
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
digital pots.
nuts and volts did an article on them, ive attached it to this email.
its fairly simple and straightforward.
norm
>From: "diacon1208" <dpotter@d...>
>Reply-To: basicstamps@yahoogroups.com
>To: basicstamps@yahoogroups.com
>Subject: [noparse][[/noparse]basicstamps] Re: Digital potentiometer
>Date: Tue, 22 Jan 2002 22:38:56 -0000
>
>I know that such chips are commercially available. Analog devices or
>Dallas semi has them. Don't know if this is the info ou are looking
>for. I haven't used them.
>
>
>--- In basicstamps@y..., "theborderlinecrew" <theborderlinecrew@y...>
>wrote:
> > Anyone have a listing for such a project?
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
I have a large DC motor and controller that I want to control from a
BS2. I really don't want to control the DC motor directly from the
BS2 and rather use the existing controller.
On the controller there is a knob with a 5k pot for speed control.
How can I by-pass that pot?
Should I measure the voltages across the leads and try to duplicate
with the stamp?
I have seen some Digital potentiometers from DigiKey but have no
clue how they work. Would this do the job?
Another idea I have is to use the small feedback pot inside a servo
motor to replace the controller speed control pot - this way I can
control the speed by controlling the servo. The question is: what
is the typical value on the servo pots (I have a few "hitec" around).
Probably the easiest thing to do would indeed be use a servo and attach it
somehow to the speed control knob. (Gears, belts, what ever). Servos are
extremely easy to control with a Stamp. The voltage is +5VDC and ground,
and use pulse out to control the position of the servo. A pulse 1 to 2 MS
is all that is required repeated 50 times per second with 1.5 ms being
centered. Piece of cake. Example code is in the Basic Stamp manual or go
to the Parallax web site under resources and look at Stamp Works experiment
# 25 and it will tell you all you need to know. SImple stuff..
MIke B.
Original Message
From: "brownstamp" <brownstamp@y...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, August 29, 2002 11:51 AM
Subject: [noparse][[/noparse]basicstamps] Digital Potentiometer
> I have a large DC motor and controller that I want to control from a
> BS2. I really don't want to control the DC motor directly from the
> BS2 and rather use the existing controller.
>
> On the controller there is a knob with a 5k pot for speed control.
>
> How can I by-pass that pot?
>
> Should I measure the voltages across the leads and try to duplicate
> with the stamp?
> I have seen some Digital potentiometers from DigiKey but have no
> clue how they work. Would this do the job?
>
> Another idea I have is to use the small feedback pot inside a servo
> motor to replace the controller speed control pot - this way I can
> control the speed by controlling the servo. The question is: what
> is the typical value on the servo pots (I have a few "hitec" around).
>
> Please help!
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
If your controller is like many I've worked with, the pot just sets a
voltage for the error amp. With a setup like that, you could easily
use a DAC on your stamp to act as the voltage from the pot. In most
cases you can put in a SPDT switch to select either manual or computer
control with very little modification to the controller. If you do
choose to use a digital pot, you need to read the spec sheet
carefully. They don't all have the same range of voltages. Also most
dig-pots have some resistance even when they are set to zero.
--- In basicstamps@y..., "brownstamp" <brownstamp@y...> wrote:
> I have a large DC motor and controller that I want to control from
a
> BS2. I really don't want to control the DC motor directly from the
> BS2 and rather use the existing controller.
>
> On the controller there is a knob with a 5k pot for speed control.
>
> How can I by-pass that pot?
>
> Should I measure the voltages across the leads and try to duplicate
> with the stamp?
> I have seen some Digital potentiometers from DigiKey but have no
> clue how they work. Would this do the job?
>
> Another idea I have is to use the small feedback pot inside a servo
> motor to replace the controller speed control pot - this way I can
> control the speed by controlling the servo. The question is: what
> is the typical value on the servo pots (I have a few "hitec"
around).
>
> Please help!
> Probably the easiest thing to do would indeed be use a servo and attach it
> somehow to the speed control knob. (Gears, belts, what ever). Servos are
> extremely easy to control with a Stamp. The voltage is +5VDC and ground,
> and use pulse out to control the position of the servo. A pulse 1 to 2 MS
> is all that is required repeated 50 times per second with 1.5 ms being
> centered. Piece of cake. Example code is in the Basic Stamp manual or go
> to the Parallax web site under resources and look at Stamp Works experiment
> # 25 and it will tell you all you need to know. SImple stuff..
>
> MIke B.
>
Original Message
> From: "brownstamp" <brownstamp@y...>
> To: <basicstamps@yahoogroups.com>
> Sent: Thursday, August 29, 2002 11:51 AM
> Subject: [noparse][[/noparse]basicstamps] Digital Potentiometer
>
>
> > I have a large DC motor and controller that I want to control from a
> > BS2. I really don't want to control the DC motor directly from the
> > BS2 and rather use the existing controller.
> >
> > On the controller there is a knob with a 5k pot for speed control.
> >
> > How can I by-pass that pot?
> >
> > Should I measure the voltages across the leads and try to duplicate
> > with the stamp?
> > I have seen some Digital potentiometers from DigiKey but have no
> > clue how they work. Would this do the job?
> >
> > Another idea I have is to use the small feedback pot inside a servo
> > motor to replace the controller speed control pot - this way I can
> > control the speed by controlling the servo. The question is: what
> > is the typical value on the servo pots (I have a few "hitec" around).
> >
> > Please help!
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"Do not fear mistakes, There Are None" - Miles Davis
Archiver
Posts: 46,084
Comments
Dallas semi has them. Don't know if this is the info ou are looking
for. I haven't used them.
--- In basicstamps@y..., "theborderlinecrew" <theborderlinecrew@y...>
wrote:
> Anyone have a listing for such a project?
digital pots. It includes code.
I have used the DS1267 and the DS1804. The 1804 is easier and more intuitive to
work with, but it takes more code
to control the wiper. It seems to me the 1267 is faster to respond, but I am
not able to measure this.
Differences in specs include, in addition to the resistance element, the number
of positions on the wiper. A high
resolution pot like the the 1267 offers 255 increments. The 1804 has 100.
If you are working on a prototype I understand, from other correspondence on
this group, you may be able to get
samples of these chips at the DS site. I think the address is www.dalsemi.com
What do you want to do with the digital pot?
Best, Michael
theborderlinecrew wrote:
> Anyone have a listing for such a project?
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
nuts and volts did an article on them, ive attached it to this email.
its fairly simple and straightforward.
norm
>From: "diacon1208" <dpotter@d...>
>Reply-To: basicstamps@yahoogroups.com
>To: basicstamps@yahoogroups.com
>Subject: [noparse][[/noparse]basicstamps] Re: Digital potentiometer
>Date: Tue, 22 Jan 2002 22:38:56 -0000
>
>I know that such chips are commercially available. Analog devices or
>Dallas semi has them. Don't know if this is the info ou are looking
>for. I haven't used them.
>
>
>--- In basicstamps@y..., "theborderlinecrew" <theborderlinecrew@y...>
>wrote:
> > Anyone have a listing for such a project?
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx
[noparse][[/noparse]Non-text portions of this message have been removed]
BS2. I really don't want to control the DC motor directly from the
BS2 and rather use the existing controller.
On the controller there is a knob with a 5k pot for speed control.
How can I by-pass that pot?
Should I measure the voltages across the leads and try to duplicate
with the stamp?
I have seen some Digital potentiometers from DigiKey but have no
clue how they work. Would this do the job?
Another idea I have is to use the small feedback pot inside a servo
motor to replace the controller speed control pot - this way I can
control the speed by controlling the servo. The question is: what
is the typical value on the servo pots (I have a few "hitec" around).
Please help!
somehow to the speed control knob. (Gears, belts, what ever). Servos are
extremely easy to control with a Stamp. The voltage is +5VDC and ground,
and use pulse out to control the position of the servo. A pulse 1 to 2 MS
is all that is required repeated 50 times per second with 1.5 ms being
centered. Piece of cake. Example code is in the Basic Stamp manual or go
to the Parallax web site under resources and look at Stamp Works experiment
# 25 and it will tell you all you need to know. SImple stuff..
MIke B.
Original Message
From: "brownstamp" <brownstamp@y...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, August 29, 2002 11:51 AM
Subject: [noparse][[/noparse]basicstamps] Digital Potentiometer
> I have a large DC motor and controller that I want to control from a
> BS2. I really don't want to control the DC motor directly from the
> BS2 and rather use the existing controller.
>
> On the controller there is a knob with a 5k pot for speed control.
>
> How can I by-pass that pot?
>
> Should I measure the voltages across the leads and try to duplicate
> with the stamp?
> I have seen some Digital potentiometers from DigiKey but have no
> clue how they work. Would this do the job?
>
> Another idea I have is to use the small feedback pot inside a servo
> motor to replace the controller speed control pot - this way I can
> control the speed by controlling the servo. The question is: what
> is the typical value on the servo pots (I have a few "hitec" around).
>
> Please help!
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
voltage for the error amp. With a setup like that, you could easily
use a DAC on your stamp to act as the voltage from the pot. In most
cases you can put in a SPDT switch to select either manual or computer
control with very little modification to the controller. If you do
choose to use a digital pot, you need to read the spec sheet
carefully. They don't all have the same range of voltages. Also most
dig-pots have some resistance even when they are set to zero.
--- In basicstamps@y..., "brownstamp" <brownstamp@y...> wrote:
> I have a large DC motor and controller that I want to control from
a
> BS2. I really don't want to control the DC motor directly from the
> BS2 and rather use the existing controller.
>
> On the controller there is a knob with a 5k pot for speed control.
>
> How can I by-pass that pot?
>
> Should I measure the voltages across the leads and try to duplicate
> with the stamp?
> I have seen some Digital potentiometers from DigiKey but have no
> clue how they work. Would this do the job?
>
> Another idea I have is to use the small feedback pot inside a servo
> motor to replace the controller speed control pot - this way I can
> control the speed by controlling the servo. The question is: what
> is the typical value on the servo pots (I have a few "hitec"
around).
>
> Please help!
On Thu, 29 Aug 2002, Mike Blier wrote:
> Probably the easiest thing to do would indeed be use a servo and attach it
> somehow to the speed control knob. (Gears, belts, what ever). Servos are
> extremely easy to control with a Stamp. The voltage is +5VDC and ground,
> and use pulse out to control the position of the servo. A pulse 1 to 2 MS
> is all that is required repeated 50 times per second with 1.5 ms being
> centered. Piece of cake. Example code is in the Basic Stamp manual or go
> to the Parallax web site under resources and look at Stamp Works experiment
> # 25 and it will tell you all you need to know. SImple stuff..
>
> MIke B.
>
Original Message
> From: "brownstamp" <brownstamp@y...>
> To: <basicstamps@yahoogroups.com>
> Sent: Thursday, August 29, 2002 11:51 AM
> Subject: [noparse][[/noparse]basicstamps] Digital Potentiometer
>
>
> > I have a large DC motor and controller that I want to control from a
> > BS2. I really don't want to control the DC motor directly from the
> > BS2 and rather use the existing controller.
> >
> > On the controller there is a knob with a 5k pot for speed control.
> >
> > How can I by-pass that pot?
> >
> > Should I measure the voltages across the leads and try to duplicate
> > with the stamp?
> > I have seen some Digital potentiometers from DigiKey but have no
> > clue how they work. Would this do the job?
> >
> > Another idea I have is to use the small feedback pot inside a servo
> > motor to replace the controller speed control pot - this way I can
> > control the speed by controlling the servo. The question is: what
> > is the typical value on the servo pots (I have a few "hitec" around).
> >
> > Please help!
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"Do not fear mistakes, There Are None" - Miles Davis