engine RPM via a hall sensor (well little off this thread)

Archiver

cool,

i was just curious about what kind of data rate you can move to you handheld?

i guess I don't really even know how many samples/sec you can pound through a
serial or parallel port.

nice for a field data acquisition system.

-pete


On Wed, 14 Mar 2001 tunatunup2000@y... wrote:

> I have been using a BS2 and a hall effect sensor to collect RPM data
> and have it displayed on a PocketPC. This is a great approach for
> data acquisition as it allows the PPC to collect the RPM data over
> time for a dynamometer program I'm writing.
>
> If your hall effect sensor gives a 5v digital output you can couple
> it directly to a input pin on the BS2 and use the BS2's count
> function to count the pulses on the pin. You may need a pull down
> resister to keep it from floating when the engine isn't running. If
> your sensor has a analog output you will need to either read the
> voltage and scale it to match the RPM or use a A/D converter w/serial
> out. National Semiconductor has a chip they make just for collecting
> Rpm's, LM2907. The LM2907 series of tachometer circuits is designed
> for minimum external part count applications and maximum versatility.
>

Archiver

I have been sampling the pulses using the count function every 500 ms
(ex: COUNT 0, 500, Cycles) but a problem I have with this is the BS2
isn't multitasking so it doesn't sample the pin while sending the
data (Using the serout function) to the device. The result is that
it's not very accurate but it was just an experiment for me on how it
might be done. I have only had my stamp about a month and still have
a lot to learn. Then OOPic may be a better choice for this
application.

Archiver

Hi,

Does anyone have a schematic or BS2 code to use the LM2907 to provide
motor rpm feedback(a tachometer type of thing).

Thanks,
Corey C.



--- In basicstamps@y..., tunatunup2000@y... wrote:
> I have been sampling the pulses using the count function every 500
ms
> (ex: COUNT 0, 500, Cycles) but a problem I have with this is the BS2
> isn't multitasking so it doesn't sample the pin while sending the
> data (Using the serout function) to the device. The result is that
> it's not very accurate but it was just an experiment for me on how
it
> might be done. I have only had my stamp about a month and still have
> a lot to learn. Then OOPic may be a better choice for this
> application.

Archiver

Al William's PAK VII can do this on eight channels and let the stamp do
other things...
Also consider measuring the time of one revolution instead of counting
pulses to save time.

Bill Heacock

---

Original Message

---

From: tunatunup2000@y... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Zj_QPIzpxg3hEHeNPEyJ34H5Ysa7_g1TjVxtn71EN_yoyYkyspTEMJM169rGhHPS88rTDmryWYj6ahD7Kg]tunatunup2000@y...[/url
Sent: Wednesday, March 14, 2001 7:13 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: engine RPM via a hall sensor (well little off
this thread)


I have been sampling the pulses using the count function every 500 ms
(ex: COUNT 0, 500, Cycles) but a problem I have with this is the BS2
isn't multitasking so it doesn't sample the pin while sending the
data (Using the serout function) to the device. The result is that
it's not very accurate but it was just an experiment for me on how it
might be done. I have only had my stamp about a month and still have
a lot to learn. Then OOPic may be a better choice for this
application.




Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Archiver

Does anyone have a schematic or BS2 code to use the LM2907 to provide
motor rpm feedback(a tachometer type of thing).

http://www.national.com/ds/LM/LM2907.pdf

Archiver

Also consider measuring the time of one revolution instead of counting
pulses to save time.


Good idea! I wish I would thought if it...