voltage to frequence
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Posts: 46,084
Hi all,
question: I want to connect a sensor with an analog output (0 to 5 V) to the
stamp using count or pulsin. Does anyone know how I can convert the voltage
into frequence using the 555? I cant find the schematics because if you ask
the web you are flooded with one million entries.
Thanx very much for help,
uli
question: I want to connect a sensor with an analog output (0 to 5 V) to the
stamp using count or pulsin. Does anyone know how I can convert the voltage
into frequence using the 555? I cant find the schematics because if you ask
the web you are flooded with one million entries.
Thanx very much for help,
uli
Comments
If memory serves, set the 555 up as an oscillator, free running
at the center of the range you want, and then apply your voltage
to pin 5 to modulate it.'
Original Message
From: <uli@r...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, May 15, 2001 10:16 AM
Subject: [noparse][[/noparse]basicstamps] voltage to frequence
| Hi all,
|
| question: I want to connect a sensor with an analog output (0 to 5 V) to the
| stamp using count or pulsin. Does anyone know how I can convert the voltage
| into frequence using the 555? I cant find the schematics because if you ask
| the web you are flooded with one million entries.
|
| Thanx very much for help,
|
| uli
|
|
|
|
| Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
|
|
|
least). A voltage applied to pin 5 (control voltage) changes the
output frequency of the 555. Here's another way. Remove the fixed
resistor that goes between Vcc to pin 7, replace this with a analog
optoisolator. Input to the opto will cause major changes to the
output freq of the 555. You may want to add resistance in series with
the opto, you may place resistance in parallel with the opto. Playing
with different values of resistance will tailor the output of the 555
to a range that is acceptable. As far as the stamp goes, I would use
the Count command, Pulsin may miss pulses if the 555 output freq goes
to low.
DISCLAIMER: All the 555 stuff is from memory, 5 weeks ago I did not
know what a BS2 was, much less how to use one. Still, this is what I
would try.
Good Luck
Rich http://geocities.com/rbc1956
--- In basicstamps@y..., uli@r... wrote:
> Hi all,
>
> question: I want to connect a sensor with an analog output (0 to 5
V) to the
> stamp using count or pulsin. Does anyone know how I can convert the
voltage
> into frequence using the 555? I cant find the schematics because if
you ask
> the web you are flooded with one million entries.
>
> Thanx very much for help,
>
> uli
These should get you started
http://www.doctronics.co.uk/555.htm#astable
and
http://www.uoguelph.ca/~antoon/gadgets/555.htm
Regards,
Daniel
Original Message
From: uli@r...
[noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=7rDQm5hF6JxjoPeB6POF2w5k6Tv41_u49k9SdwCzpmJpoZ7YUsZrUnM9U6-0FsFEUjRsZRyyTgt795rLZCpbNqbh1A]uli@r...[/url
Sent: Tuesday, 15 May 2001 11:34
To: basicstamps@yahoogroups.com
Subject: AW: [noparse][[/noparse]basicstamps] Re: voltage to frequence
First of all, thanx to you all, but:
Is there any hint you can give me where I can find the very basic
information about the 555? I know, everybody except me knows what "use it as
an oscillator" means, but I dont.
Has anybody a link to 555-page? I tried to find one, but i couldnot figure
one out yet.
thanx very much again,
Uli
www.raumschiff-interactive.de
stamp counts pulses,which come from the 555, which are proportional
to a sampled voltage. Why not use a serial A/D converter designed for
that purpose. Information about using this A/D converter is available
at the Parallax website.
I'm sorry, I can't think of a URL showing 555 applications. Why not
log onto National Semiconductors website. I believe they (among many
others) manufacture the 555. Pull the datasheet. The datasheet should
show basic application data, including astable (free-running) and
monostable (one-shot) operation of the 555. Maybe ratshack has
a "mini-enginneering" 555 book. You never know.
Ciao
Rich http://geocities.com/rbc1956
--- In basicstamps@y..., uli@r... wrote:
> First of all, thanx to you all, but:
>
> Is there any hint you can give me where I can find the very basic
> information about the 555? I know, everybody except me knows
what "use it as
> an oscillator" means, but I dont.
> Has anybody a link to 555-page? I tried to find one, but i couldnot
figure
> one out yet.
>
> thanx very much again,
>
> Uli
>
> www.raumschiff-interactive.de
>
>
Urspr
how you wire them together it does different things.
Read: http://www.uoguelph.ca/~antoon/gadgets/555.htm
Which is as good a treatment of them as I have seen.
The basic idea is you have two comparators, a flip flop, and transistor
switch.
You charge and discharge an external capacitor through various resistors. By
using different resistors for each path, and setting the comparator levels,
you can turn the pulse on and off at different times in different
conditions.
For higher frequencies there are other ways to do this. Any VCO design will
work (including the VCO in a 567 tone decoder PLL).
VCOs work in several different ways. Some work like the 555 by comparing the
voltage to an RC charge. Some use a varactor which is a reverse-bias diode
that is made specifically to exhibit high capacity (all diodes have
capacitance when their PN junction is depleted -- after all, you have two
conductors and an insulating middle and that's a capacitor). The capacitance
from a varactor can pull a crystal or other frequency-determining element.
Regards,
Al Williams
AWC
*NEW: Connect your Stamp to the Internet:
http://www.al-williams.com/awce/netporter.htm
>
Original Message
> From: uli@r...
> [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lFrcLPvD4PELXSxrFTfeuU1kHZT4iQlmgJ5iXzA7WP5YZLq_Mfl-q6pyaqUBZtJbcM9qecTh9OtSHJl1TIycz6PaUwuQs2KG]uli@r...[/url
> Sent: Tuesday, May 15, 2001 10:34 AM
> To: basicstamps@yahoogroups.com
> Subject: AW: [noparse][[/noparse]basicstamps] Re: voltage to frequence
>
>
> First of all, thanx to you all, but:
>
> Is there any hint you can give me where I can find the very basic
> information about the 555? I know, everybody except me knows what
> "use it as
> an oscillator" means, but I dont.
> Has anybody a link to 555-page? I tried to find one, but i couldnot figure
> one out yet.
>
> thanx very much again,
>
> Uli
>
> www.raumschiff-interactive.de
>
>
Urspr
I'm very sorry for that assumption.
If you have access to a fax machine, please send me the number
and I will fax the databook pages to you.
Russ
Original Message
From: <uli@r...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, May 15, 2001 11:34 AM
Subject: AW: [noparse][[/noparse]basicstamps] Re: voltage to frequence
| First of all, thanx to you all, but:
|
| Is there any hint you can give me where I can find the very basic
| information about the 555? I know, everybody except me knows what "use it as
| an oscillator" means, but I dont.
| Has anybody a link to 555-page? I tried to find one, but i couldnot figure
| one out yet.
|
| thanx very much again,
|
| Uli
|
| www.raumschiff-interactive.de
|
|
Urspr
http://www.bobblick.com/bob/stamp/555a_d/index.html
Friendly Regards
Octavio Nogueira
===================================================
nogueira@p... ICQ# 19841898
ProPic tools - low cost PIC programmer and emulator
http://www.propic2.com
===================================================
Original Message
From: <uli@r...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, May 15, 2001 11:16 AM
Subject: [noparse][[/noparse]basicstamps] voltage to frequence
> Hi all,
>
> question: I want to connect a sensor with an analog output (0 to 5 V) to
the
> stamp using count or pulsin. Does anyone know how I can convert the
voltage
> into frequence using the 555? I cant find the schematics because if you
ask
> the web you are flooded with one million entries.
>
> Thanx very much for help,
>
> uli
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
want is
http://www.bobblick.com/bob/stamp/555a_d/index.html this is just what you asked
for. He also
has a Nickel-Metal Hydride Battery Charger/Conditioner/Sequencer that uses the
555 as a cheap
A/D with a Basic Stamp 1
>
> Date: Tue, 15 May 2001 16:16:14 +0200
> From: uli@r...
> Subject: voltage to frequence
>
> Hi all,
>
> question: I want to connect a sensor with an analog output (0 to 5 V) to the
> stamp using count or pulsin. Does anyone know how I can convert the voltage
> into frequence using the 555? I cant find the schematics because if you ask
> the web you are flooded with one million entries.
>
> Thanx very much for help,
>
> uli
a couple of free samples of each, and they are dead easy to interface with
the Stamp (see Shaun's Basic Stamp pages, don't have the url right now, it
is on Parallax's links page).
James.
> Hello there,
>
> thanx to all who helped me, the bobblick-page is all i needed and also i
am
> testing a ltc1298 AD converter.
> What the hell did the world do before there were newsgroups?
>
> Big thanx to all of you again.
>
> Uli