32.768khz as Output on a Propeller Pin
Hi
I would like to connect a Barometric Pressure Sensor (MS5534B from [noparse][[/noparse]http://www.intersema.ch]).
The Sensor is a 3.3V Device and it seems to be hard to connect it to my AVR Atmega128 Chip, so i'am
thinking about a change to the Propeller Device as the MCU. Also to keep my Brain up and running![wink.gif](http://forums.parallax.com/images/smilies/wink.gif)
The Problem is now, the Sensor needs a 32.768khz Input as his MasterClock. One way is using a
Oscillator, but they are hard to get. The other way is, setting up a 32.768khz signal on one of
the pins of the MCU. That means, i connect one of the Propeller Pins with the MCLK Pin of the
Sensor and that's it.
Question:
Is this possible and does it make sense on a propeller chip ? If yes, does anybody have a snippet
of code for me ?
Regards,
Daniel
I would like to connect a Barometric Pressure Sensor (MS5534B from [noparse][[/noparse]http://www.intersema.ch]).
The Sensor is a 3.3V Device and it seems to be hard to connect it to my AVR Atmega128 Chip, so i'am
thinking about a change to the Propeller Device as the MCU. Also to keep my Brain up and running
![wink.gif](http://forums.parallax.com/images/smilies/wink.gif)
The Problem is now, the Sensor needs a 32.768khz Input as his MasterClock. One way is using a
Oscillator, but they are hard to get. The other way is, setting up a 32.768khz signal on one of
the pins of the MCU. That means, i connect one of the Propeller Pins with the MCLK Pin of the
Sensor and that's it.
Question:
Is this possible and does it make sense on a propeller chip ? If yes, does anybody have a snippet
of code for me ?
Regards,
Daniel
Comments
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·
I've found this fragment of code somewhere in this Forum. I'll try to
adept this for my need.
Which way to go depends on how accurate you need the reference signal to be, if it were a time keeping chip, I would suggest a rock-solid clock, but I don't know with a barometric pressure sensor.
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
Post Edited (Paul Baker (Parallax)) : 12/12/2006 12:41:26 AM GMT
-Phil
far as i understand (i'am not a Hardware-Guy...) The Pressure Sensor has only one so-called
MCLK Pin and not two Pins to connect a 32.768khz Crystal. You have to use a DS32khz from Dallas
or a SG-3032JC from Epson, and they are all very hard to get here in Switzerland. And also
i can save some Hardware (good for a Software-Guy
I'll try it.
Thanks and Good night
I'd be interested to learn of your experiences with this device. I have some samples of both it and the newer MS5540B that I've been contemplating for a design. (BTW, if you haven't looked at the '5540, it's a little more PCB-friendly, in that it's flat on one side.)
Thanks,
Phil
You could make your own oscillator with the 32.768kHz crystal, a CMOS inverter and two caps (and possibly a resistor, I can't remember). You should be able to find a sample schematic on the web. And all components at Distrelec or Farnell.