X10 barometer

Post by **Han** » Sat May 27, 2006 3:40 pm

I just finished a X10 barometer. I used the MS5534A manufactured by Intersema (http://www.intersema.ch/site/technical/ms5534.php). It delivers absolute pressure and is easy to integrate with a PIC microcontroller (using the SPI module). After some calculations and taking into account the temperature (which can also be read from the MS5534A), a very accurate pressure value is obtained and can be transmitted by means of X10. Hardware: [img]images/icon_paperclip.gif[/img] x10_bar.jpg, The MS5534A is visible at the left side.

Han Alink

Post by **VSCP** » Mon Jun 12, 2006 3:12 pm

Hi Han,

Do you mind publishing your Firmware?

Henk

PS. What Pic controller are you using?[:)]

Post by **Han** » Mon Jun 12, 2006 3:59 pm

Hello Henk,
Do you mean the firmware for communication with the MS5534A?
I'm using a 16LF819 for this one. The LF version as the sensor has a max. supply voltage of 4 Volts. The 16F819is not specified for this supply voltage, the LF version is.

Han Alink

Post by **VSCP** » Fri Jul 07, 2006 11:06 am

Hi Han,

I am also interested in testing the pressure sensor from Intersema. Do you know how close this sensor works to 0 mBar? (Want to use this sensor as an altimeter) Can you make measurements with this sensor upto 10Hz?
As always it would be nice to use your tested functions, so I could merge them into my application. (Hopefully you use C!?)
Finally which supplier has the best price? Is it possible to get a sample from Intersema?

Henk (sorry for the late response.)

Post by **Han** » Mon Jul 10, 2006 2:37 pm

Hello henk,

I have been on holiday for a few weeks, so I would not have noticed an earlier response.
I'm not using the sensor for altitude measurement, and did not test it for that purpose. But reading the documentation http://www.intersema.ch/site/technical/files/an501.pdf I think the device is very well capable of doing the things you want.
All my code is in assembler. This is probably an advantage for the communication with the sensor (using an SPI interface). As I'm using the build in SPI hardware for communicating with a second PIC (The one that does the X10 communication), I had to "build" a software SPI interface for comunication with the sensor.
As you can see from the documentation, there a lot of calculations to be done. That probably would be much more easy in C, but I have used assembler code for this task too.
If you are still interested in this code, please contact me by email and we will discuss this further.
I ordered the device from the German distributor:http://www.amsys.de/ (There is no Dutch distributor). They sell at the same price as Intersema and use the same conditions: €17,75 for the device and € 25,- for transportation.
I ordered 2 (have one left, interested?)

Han Alink

Post by **VSCP** » Mon Jul 17, 2006 1:19 am

Hi Han,

Very busy lately and then I forget looking at the forum. Yes I mean the firmware communicating with the sensor.

Henk

Post by **Han** » Mon Jul 17, 2006 10:17 am

Hello Henk, I think you are out of sync. Have a look at my earlier replies.

Han Alink

Post by **VSCP** » Mon Jul 17, 2006 8:41 pm

Han,

Yes out of sinc, normally a new post is on the top? I also thought your reply was a bit strainge too....

Yes I am interested in the asm code, and yes I am intested in the sensor. (Do you have a friendly price in mind?) This one will probably go with our next rocket launch (see www.nerorockets.org)

Henk.

Ps. Is the sensor sensible to acceleration?

Post by **Han** » Tue Jul 18, 2006 12:12 pm

I will contact you by email.

Han Alink