sensor that recognizes when it's upside down

I am looking for a simple small cheap sensor that will recognize when it is flipped upside down. ie i want to put it in a cell phone so
when I turn the phone over the screen knows to flip because of the sensor.
does anyone know what type of sensor that is called and where i could possibly find one?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gmail.com wrote:

The mercury switch used to be the simple solution for this. If you can't buy one new, maybe you could salvage one by upgrading an old home thermostat? I once had a simon-like toy that used a ball bearing to detect which of 6 areas was up. Never opened it to see whether it pressed normal pushbuttons or just shorted exposed contacts...
Here's another variant: http://www.instructables.com/id/E14GB1P4ZNEXCFFZCM /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Jul 11, 4:44 pm, snipped-for-privacy@gmail.com wrote:

You could use a tilt sensor. But be careful, some of them use a small metal ball that may rattle if someone shakes the phone.
Or you could use an acceloremeter. They can detect if gravity is pulling in the "wrong" direction.
Before you spend too much time trying to figure out how to flip the screen, you should think about why you are flipping it. It seems like bad UI design to me. If someone is using their phone while lying in bed or whatever, they may find it quite annoying if the screen suddenly flips upside down.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bob wrote:

If you're a hobbyist, see this:
http://www.itcelectronics.com/product_info.php?products_id814&osCsid bd1ac4fd2758a18be5851b1925400c
Philmore Non Mercury Tilt Switch SPST Open-Closed Dependent upon tilt ang Part No.: 30-17072      $1.52 Non Mercury Tilt Switch SPST Open-Closed Dependent upon tilt ang Click to enlarge
Non Mercury Tilt Switch SPST Open-Closed Dependent upon tilt angle 5A @ 24V AC.
If you're designing a cell phone, you want a surface-mount part, which you should be able to find yourself.
                    John Nagle
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Jul 11, 6:44 pm, snipped-for-privacy@gmail.com wrote:

You probably want a 3 axes accelerometer.
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLJ,GGLJ:2006-37,GGLJ:en&q celerometer+3+axes
http://www.sparkfun.com/commerce/product_info.php?products_id%2
They aren't cheap in low quantities, but they are really small. As long as the cell phone is in nonaccelerated motiong (moving steadily without speeding up or slowing down (i.e. resting on a table or in your hand) this will let you sense :"down" because gravitational acceleration can not be distinguished from a constant acceleration. Good ole Einstein figured that one out for us.
-- Randy M Dumse. www.newmicros.com Caution: Objects in mirror are more confused than they appear.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, you can use an accelerometer, but it might be a lower cost option to use a light sensor, e.g. a photodiode. I used this sucessfully on a recent camera that I designed. The prototype camera would power off when placed on a table and so extend battery life. Lyndsay Williams www.lyndsayw.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.