Number of samples + more than one program
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Hey,
sorry for the fact that my problem wasn't very clear.
I want to run a stepper motor. When he is running I want to read
some voltages from an outside source. After I have read the voltages
I want to stop the stepper.
Is there someaone who knows how much data I can write in EEPROM and
at wich sample rate (number of samples per second)
Thks
--- In basicstamps@yahoogroups.com, Bill Boyer <daweasel@s...> wrote:
> Sounds to me like he wants to mount a Sharp sensor with an analog
output
> on a stepper and have it scan / measure at the same time.
>
> If so, you will probably have to stop the sensor movement each
time you
> take a reading to get it to work properly. You can use one of those
> stepper control chips that requires only step and direction
inputs, or
> you can use individual transistors to fire each coil in the proper
> sequence.
>
> > I'm not sure I totally understand your post.
> >
> >
> > you want to run a stepper and montior something ? is this for a
> > feedback control loop ? Not terribly hard to do.
> >
> > Steppers work (usually) on one pulse is one movement of the
> > armature. a single step would be on step per pulse with a step
being
> > the distance listed on the nameplate. often 1.8 degrees for 200
> > steps per revolution. (many many different varieties so be
careful)
> >
> > next, is what are you trying to contorl ? if you are making a
> > turntable and need to 'adjust' the speed, considder a DC servo
motor
> > (not a hobby servo) as that inplies a feedback for rpm. the DC
servo
> > motor is really just a simple DC motor with feedback. great for
> > constant or variable speeds.
> >
> > the stepper is great for single steps.
> >
> > If you are contorlling a valve and watching the water level,
then the
> > amount of time you are runnng the stepper is so slight, it is
easy to
> > monitor the process, do a PID loop, and then reposistion the
motor.
> >
> > a little more is needed on what you are trying to do.
> >
> > and as far as memory goes, problably a good idea to make a
seperate
> > post, or is someone replies, to fix the subject line.
sorry for the fact that my problem wasn't very clear.
I want to run a stepper motor. When he is running I want to read
some voltages from an outside source. After I have read the voltages
I want to stop the stepper.
Is there someaone who knows how much data I can write in EEPROM and
at wich sample rate (number of samples per second)
Thks
--- In basicstamps@yahoogroups.com, Bill Boyer <daweasel@s...> wrote:
> Sounds to me like he wants to mount a Sharp sensor with an analog
output
> on a stepper and have it scan / measure at the same time.
>
> If so, you will probably have to stop the sensor movement each
time you
> take a reading to get it to work properly. You can use one of those
> stepper control chips that requires only step and direction
inputs, or
> you can use individual transistors to fire each coil in the proper
> sequence.
>
> > I'm not sure I totally understand your post.
> >
> >
> > you want to run a stepper and montior something ? is this for a
> > feedback control loop ? Not terribly hard to do.
> >
> > Steppers work (usually) on one pulse is one movement of the
> > armature. a single step would be on step per pulse with a step
being
> > the distance listed on the nameplate. often 1.8 degrees for 200
> > steps per revolution. (many many different varieties so be
careful)
> >
> > next, is what are you trying to contorl ? if you are making a
> > turntable and need to 'adjust' the speed, considder a DC servo
motor
> > (not a hobby servo) as that inplies a feedback for rpm. the DC
servo
> > motor is really just a simple DC motor with feedback. great for
> > constant or variable speeds.
> >
> > the stepper is great for single steps.
> >
> > If you are contorlling a valve and watching the water level,
then the
> > amount of time you are runnng the stepper is so slight, it is
easy to
> > monitor the process, do a PID loop, and then reposistion the
motor.
> >
> > a little more is needed on what you are trying to do.
> >
> > and as far as memory goes, problably a good idea to make a
seperate
> > post, or is someone replies, to fix the subject line.
Comments
>at wich sample rate (number of samples per second)
If you are talking about the EEPROM in the Stamp, you can use any of
it for your data that is left over after your program. The original
BS2 has 2048 bytes of EEPROM, so if your program happens to use 748
bytes, then there will be 1300 bytes left for data. If you have one
of the multibank stamps, there is a lot more available. For example,
the 'pe has a total of 32768 bytes program+data, in 16 banks.
Writing to the EEPROM is relatively slow. You have to WRITE one byte
at a time, and it takes about 3 to 5 milliseconds for each byte, so
an efficient program might be able to do 100 bytes per second.
Remember that EEPROM has a limited life for re-writing.
-- Tracy