I came across an app (CPUZ for Android in the Google store) which I
wanted for another reason. I was rather surprised that there's a
barometer in my Samsung S3 giving hPa to one decimal place. I have no
idea how many phones have this sensor, but the app is free.

One in mine too, Galaxy Note. A few apps use it.
With their next release Apple are going with an iVantage Pro variant.

On Sunday, 13 July 2014 18:22:10 UTC+1, Tim wrote:
I came across an app (CPUZ for Android in the Google store) which I wanted for another reason. I was rather surprised that there's a barometer in my Samsung S3 giving hPa to one decimal place. I have no idea how many phones have this sensor, but the app is free.

Us it as an altimeter. 37 mb per thousand feet.

Tudor Hughes, Warlingham, surrey.

On 14/07/2014 02:53, Tudor Hughes wrote:
On Sunday, 13 July 2014 18:22:10 UTC+1, Tim wrote:
I came across an app (CPUZ for Android in the Google store) which I wanted for another reason. I was rather surprised that there's a barometer in my Samsung S3 giving hPa to one decimal place. I have no idea how many phones have this sensor, but the app is free.

Us it as an altimeter. 37 mb per thousand feet.

Tudor Hughes, Warlingham, surrey.


It would be interesting to know just how this android unit works for
barometric pressure. A quick Google and I'm none the wiser. If it is a
barometric pressure sensor, which I doubt, then all well and good.
Nevertheless that will still require regular resetting to QFE or QNH,
for example, in order to provide accurate altitude. However if the
'phone is calculating pressure from the GPS sensor then the
altitude/pressure will be less accurate-see below. On the other hand for
*changes* in these parameters then it would be fine.

Civilian GPS are fine for navigation being accurate to within 5-10m
(horizontally) 95% of the time but only 15-20m (vertically) 95% of the
time. (Military GPS are better than this).

A neighbour was recently singing the praises of his Garmin GPS. He
quoted an altitude for our location which as I pointed out would put us
some distance away at the foot of the hill close to a busy road. The
definitive source for altitude is the OS map with the 175m contour
passing through our gardens.

I must get out more

--
George in Swanston, Edinburgh, 575'asl
www.eppingweather.co.uk
www.winter1947.co.uk

On Sunday, July 13, 2014 6:22:10 PM UTC+1, Tim wrote:
I came across an app (CPUZ for Android in the Google store) which I

wanted for another reason. I was rather surprised that there's a

barometer in my Samsung S3 giving hPa to one decimal place. I have no

idea how many phones have this sensor, but the app is free.

I am surprised you didn't find http://developer.android.com/guide/t..._overview.html

On 14/07/2014 13:30, zaax wrote:
On Sunday, July 13, 2014 6:22:10 PM UTC+1, Tim wrote:
I came across an app (CPUZ for Android in the Google store) which I

wanted for another reason. I was rather surprised that there's a

barometer in my Samsung S3 giving hPa to one decimal place. I have no

idea how many phones have this sensor, but the app is free.

I am surprised you didn't find http://developer.android.com/guide/t..._overview.html

Or indeed this item (the sensor datasheet);
http://www.pololu.com/file/download/...?file_id=0J622

In article ,
says...
If it is a
barometric pressure sensor, which I doubt, then all well and good.


Bosch bmp180 digital sensor usually on modern phones. Older phones
generally used the bmp085. Bosch appear to have a near monopoly in this
market. They are /surprisingly/ accurate being able to detect altitude
changes of just a couple of cm.

ANd yes, it's primary purpose is to fine tune the gps altitude readings.


--
Alan LeHun
Reply-to is valid. Add "BPSF" to subject: to bypass spam filters.

In article , says...
Or indeed this item (the sensor datasheet);
http://www.pololu.com/file/download/...?file_id=0J622



And I was of the belief that the bosch bmp180 sensor was de rigueur in
modern phones and unsurpassed. Looking into it, it looks as though only
the nexus models ever used it and the ST chip is quite a bit more
accurate by a factor of 5 or so.

Ho hum. Live and learn.


I don't suppose you know if this chip is used in the S4?

--
Alan LeHun
Reply-to is valid. Add "BPSF" to subject: to bypass spam filters.

On 15/07/2014 02:18, Alan LeHun wrote:
In article , says...
Or indeed this item (the sensor datasheet);
http://www.pololu.com/file/download/...?file_id=0J622



And I was of the belief that the bosch bmp180 sensor was de rigueur in
modern phones and unsurpassed. Looking into it, it looks as though only
the nexus models ever used it and the ST chip is quite a bit more
accurate by a factor of 5 or so.

Ho hum. Live and learn.


I don't suppose you know if this chip is used in the S4?

I don't know about the S4, but you could try the XDA-Developers forum.

On Tuesday, 15 July 2014 01:50:48 UTC+1, Alan LeHun wrote:
In article , says... If it is a barometric pressure sensor, which I doubt, then all well and good. Bosch bmp180 digital sensor usually on modern phones. Older phones generally used the bmp085. Bosch appear to have a near monopoly in this market. They are /surprisingly/ accurate being able to detect altitude changes of just a couple of cm. ANd yes, it's primary purpose is to fine tune the gps altitude readings.

How can it fine-tune the GPS height without a reference MSL pressure at the point and time of observation and where does it get that from? How accurate is the reference MSL pressure? Precision aneroids are fairly thin on the ground, at least in this part of the world.

Tudor Hughes, Warlingham, Surrey