greenale

I'm sorry, I don't have any more codes. I got only 50 codes, and posted all of them on the internet already.

The app is available for $0.99: http://itunes.apple.com/us/app/acoustic-ruler-pro/id47508196...

The biggest source of error is actually the variation in the speed of sound. It increases around 2% when the temperature increases 10°C. Then there is a source of error because it seems the clock frequency of the ADC/DAC on the iPhone is not 100% accurate. If you recalibrate the app with a known distance (by moving the temp. slider until the displayed distance matches the actual distance) it should be pretty precise. No warranties, however. If the noise level is too high, it usually just doesn't show the measurement. There's one other source of error, that was actually the hardest to filter out: The sound doesn't only travel on the shortest path (line-of-sight) but on many paths. And often the sound from the longer paths arrive amplified, compared to the shortest path.

Thanks for telling me!

Have some more:

    JH4FKF7L4MR7
    HALW7E3RWFRN
    AM69Y3A6HLYF
    YNJYRTAFEKLL
    4MJW7RWY346L
    9339EPNA3JT6

Thank you HN for your tremendous interest!

AFAIK Sonar Ruler works by reflecting the sound off a wall e.g.

My app supports a dual-device mode where you can measure the distance between two iOS devices, and it works reliably up to 25 meters.

Thanks for your feedback.

In theory it would be possible to tell the temperature if you have a know distance. The only problem seems to be that the clock of the ADC/DAC is often not running exactly at its nominal frequency. So, if you have a known distance, slide the temperature slider until the result matches (this works even after the measurement is complete). I've thought about this problem but decided against having an additional slider for the clock calibration, because I think that would have been to difficult to understand.

Thanks to soulashell and Amaan for pointing out all codes are gone. Strangely there is no reply link on your posts.

Enjoy some more:

    LKNYJXP6JMKF
    F3K7JNAXWHMF
    T9P4L7JE4LF4
    AYERK4LE33X6
    4KWJETFKJFFR
    J7KFM7W737MW
    HK4FFTW6WJPY

Thanks for reporting this!

    HXRH69ATPNEX
    TF7YAPRHJWH7
    RFPEPJEYMJFP
    WMWWRAWNXAXL
    7RJKAMNA9AFE
    6F93JHNXMHYM
    EKWRFRRYM6JH

Thanks for telling! Here are some more:

    37LFWL69JKTT
    L7F9JEEKAT6K
    JPJN7FYAHWL3
    F37FNWN3WETR
    H9FERRJ3TXJ9
    PA3YLRJ7AKAM
    RYEEFTPW4H9W
    ANLW6N6XFY4E

Did you try the codes? Are all taken already? Please let me know because then I will post some more

Hello HN! Here are some promo codes for you:

    M7TF3KPJH3WX
    KJXW974YELWX
    PE6RANNF4R6Y
    ARYLPNJY36XX
    M9EHXA694JER

You can redeem them as follows:

1) On your iPhone/iPod/iPad, tap the App Store icon from the Home Screen.

2) Navigate to the New section on the Featured tab.

3) Scroll to the bottom of the list to locate and tap the Redeem button.

4) Enter the promo code and tap the Redeem button in the upper right.

5) Tap done on the Thank You screen, then tap the home button to return to the home screen.

6) After a second, you should see the my app installing. (If the promo code was not used before...)

7) Please upvote if you took a code and leave a comment telling which was your code (so the next person doesn't have to try in vain).

8) If all codes are used up, please reply to this comment, I will then post more. This is more efficient than posting all codes at the start.