BMP180

52 views
Skip to first unread message

Hans van Veldhuizen

unread,
May 6, 2024, 1:07:45 PM5/6/24
to jallist
Hello,
The BMP180 is a ready-made barometer/temperature module, for I2C. Has anyone done anything with this before?
regards
hans

David VB

unread,
May 9, 2024, 9:58:18 AM5/9/24
to jallist
Hi Hans,

I do not, but I had a look on the datasheet....

It seems that this sensor requires a lot of computation in the µC to make the result usable.

I am not sure that 8-bit PIC's are the best choice for this kind of application.
With the help of JAL, they are able of performing floating-point calculation, but the complexity here will surely pile up a lot of rounding errors.

It *could* work, but you surely will have to add some tricks here and there to enhance the precision of the computation

Besides, there are other sensors in the market, and maybe, some of them are easier to use.

For temperature, you can use a classic LM35.  Some variations (see the datasheet) are very precise and easy to incorporate in an application.
For pressure, I never used a sensor, so I cannot give you another reference (Bosch has many variant in the BMPxxx series, but other manufacturers exist)

Try to get a list of pressure sensors on Digikey or Mouser, have a look on their datasheet to see what they require as computational power to get the result.
Have a look also at mikroe.com : they design and sell nice modules and often, there are librairies in C, Pascal and Basic available to use them: you could get inspiration from there to write your own jal library

Have a nice day,

David

Hans van Veldhuizen

unread,
May 9, 2024, 12:47:03 PM5/9/24
to jallist
I got some of those things as gifts. What I think I can use doesn't require great accuracy. I have also looked through the database and the calculations are indeed a complex matter.
If I were able to read the raw data I would be well on my way.
But my problem is right at the beginning. I have once saved and read some data with I2C, but there is a lib for that. Other than that it is very dark for me.
Page 15 shows exactly what needs to be done, but how do I get that done ??????????
regards
Hans

Op donderdag 9 mei 2024 om 15:58:18 UTC+2 schreef David VB:

Rob CJ

unread,
May 9, 2024, 2:35:35 PM5/9/24
to jal...@googlegroups.com
Hi Hans,

The calculation is not as complex as it seems. It are just some calculations given in separate steps.

I do not know if there are more JAL users that have plans to use this module. If so you can send me one module and I can create a JAL library 🙂.

Kind regards,

Rob

Van: jal...@googlegroups.com <jal...@googlegroups.com> namens Hans van Veldhuizen <hanz...@zeelandnet.nl>
Verzonden: donderdag 9 mei 2024 18:47
Aan: jallist <jal...@googlegroups.com>
Onderwerp: [jallist] Re: BMP180
 
--
You received this message because you are subscribed to the Google Groups "jallist" group.
To unsubscribe from this group and stop receiving emails from it, send an email to jallist+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/jallist/d8461e7b-1d5e-4115-b004-434f3cbbf9fbn%40googlegroups.com.

Hans van Veldhuizen

unread,
May 10, 2024, 5:04:30 AM5/10/24
to jallist
Hello Rob,
Great, I'll send it.
regards
Hans

Op donderdag 9 mei 2024 om 20:35:35 UTC+2 schreef Rob CJ:

Rob CJ

unread,
May 10, 2024, 10:17:56 AM5/10/24
to jallist
Hi Hans,

OK, thanks. I started programming. Maybe I have completed a first version of the library before I have your device.

It does not seem to be a complex library when following the calculations of the data sheet.

Kind regards,

Rob

Verzonden: vrijdag 10 mei 2024 11:04
Aan: jallist <jal...@googlegroups.com>
Onderwerp: Re: [jallist] Re: BMP180
 

rob...@hotmail.com

unread,
May 18, 2024, 5:21:32 AM5/18/24
to jallist
Hi all,

I uploaded a library and sample program for the bmp180 temperature and pressure sensor.

Took some time to get the calculations correct. A lot of casting was required but it finally worked.

Thanks to Hans for the module on which I could test the library.

Kind regards,

Rob


Op maandag 6 mei 2024 om 19:07:45 UTC+2 schreef Hans van Veldhuizen:

Hans van Veldhuizen

unread,
May 21, 2024, 4:39:50 PM5/21/24
to jallist
Hello Rob and others,
I am very happy with this lib. Especially since I can use it with the WISP again.
 As always, I keep having problems with the PICs that can not longer be operated with the WISP.
Thanks Rob

Op zaterdag 18 mei 2024 om 11:21:32 UTC+2 schreef rob...@hotmail.com:

Rob CJ

unread,
May 22, 2024, 12:54:33 PM5/22/24
to jal...@googlegroups.com
Hi Hans,

Glad that you like it and use it. BTW. When uploading this library to GitHub I discovered a similar library for the bmp085 but that library is not in the Jallib release. I do not know why. I saw that it was not fully compliant with the Jallib Style Guide but do not know if that was the reason. 

About JAL libraries. In 2020 I had sent out a poll asking which libraries JAL users wanted and in that year I made quite a lot of libraries. From most of them I know they are used (also by you) but for some of them I do not know that. 

Especially the library for the Si5351, a clock generator IC. This was one of the most complex chips for me to create a library for but I never heard anybody using it (but it was requested). So if anybody is using it, that would be nice to know.

Kind regards,

Rob



Verzonden: dinsdag 21 mei 2024 22:39

Aan: jallist <jal...@googlegroups.com>
Onderwerp: [jallist] Re: BMP180
--
You received this message because you are subscribed to the Google Groups "jallist" group.
To unsubscribe from this group and stop receiving emails from it, send an email to jallist+u...@googlegroups.com.

Hans van Veldhuizen

unread,
May 22, 2024, 1:42:48 PM5/22/24
to jallist
Hans_jal.jpg

Op woensdag 22 mei 2024 om 18:54:33 UTC+2 schreef Rob CJ:

Hans van Veldhuizen

unread,
May 23, 2024, 1:26:36 PM5/23/24
to jallist
Hello ,
Here it is.
The former weather house responds to the humidity
This works on the barometer setting. A stable high pressure sends the "barefoot" outwards and if the pressure has dropped in the last few hours, it will already move backwards a bit. At an average value like now, they both have doubts, but when the pressure drops the "umbrella" emerges.
Not that it is suddenly all reliable, but it is still about fun.
regards
Hans20240523_191415.jpg

Op woensdag 22 mei 2024 om 19:42:48 UTC+2 schreef Hans van Veldhuizen:

Rob CJ

unread,
May 23, 2024, 1:30:59 PM5/23/24
to jal...@googlegroups.com
Hi Hans,

A very nice project!

Well done.

Kind regards,

Rob
Verzonden: donderdag 23 mei 2024 19:26

Aan: jallist <jal...@googlegroups.com>
Onderwerp: Re: [jallist] Re: BMP180

Hans van Veldhuizen

unread,
Jun 16, 2024, 4:17:28 AM6/16/24
to jallist
Because I still had so many legs of the PIC free, I added a few things. except display it tells what time it is on request.
So a new picture, but the weather remains miserable !!
regards
Hans20240610_164116.jpg

Op donderdag 23 mei 2024 om 19:30:59 UTC+2 schreef Rob CJ:

Rob CJ

unread,
Jun 16, 2024, 7:16:55 AM6/16/24
to jal...@googlegroups.com
Hi Hans,

Nice. What is S : 125?

Kind regards,

Rob

Verzonden: zondag 16 juni 2024 10:17
Reply all
Reply to author
Forward
0 new messages