4 ms·

> I wouldn't be surprised if by playing some clever tricks with the accelerometer you could even replace the bathroom scale. Galileo might take issue with that

by drcode 16y ago

> I wouldn't be surprised if by playing some clever tricks with the accelerometer you could even replace the bathroom scale. Galileo might take issue with that: http://www.jimloy.com/physics/galileo.htm http://www.jimloy.com/physics/galileo.htm

deleted 16y ago
[deleted]
ghshephard 16y ago
That's going down. What about going up? And yes, it's not straight-forward - like pg said, "clever tricks."
brc 16y ago
I'm glad there aren't too many dumb readers of HN. Otherwise we'd see a post 'I just stood on my iPad and now the screen is cracked'.
- ph0rque 16y ago
  Well, the length of the crack would be proportional to the weight, and you could calculate the number from that :~)
maxklein 16y ago
The best way I could think of to actually use the iPad for this would be have a person lay his arm (including wrist) on it. The iPad can use the touch sensitive surface to measure how thick his wrist is and how thick his arm is, and then guess his weight. Using an accelerometer would likely be a worse user experience than just stepping on a scale, but a system where the iPad actually measures your body fat could be easier to use. However, it will likely not be very accurate. Perhaps if one were to set a reference weight at the start, and it just measures delta using the touch screen? Using the accel, a possibility is to see how close a person can swing the iPad towards his body. I assume that this would change dependent on the amount of fat around his arms. A common place people gather fat is on their thighs - thin people often have space between the legs and heavier people not as much. Also a possibility, even if a not very clever one.
- nosse 16y ago
  "Using the accel, a possibility is to see how close a person can swing the iPad towards his body." http://library.thinkquest.org/C003763/index.php?page=planet08 http://library.thinkquest.org/C003763/index.php?page=planet0... So it would be possible to give an estimate of upper body weight if a person would swing the iPhone with hand straight. It could give the body mass as a multiple of the hands mass. It would be easy to cheat though.
pmjordan 16y ago
What about a dumb add-on mechanism which acts as a cradle for the tablet and which tilts it at an angle depending on the downward force? That was my first thought, anyway. I'm sure the concept (accelerometer = orientation sensor) can be refined.

by drcode 16y ago

deleted 16y ago

[deleted]

ghshephard 16y ago

That's going down. What about going up? And yes, it's not straight-forward - like pg said, "clever tricks."

brc 16y ago

I'm glad there aren't too many dumb readers of HN. Otherwise we'd see a post 'I just stood on my iPad and now the screen is cracked'.

ph0rque 16y ago
Well, the length of the crack would be proportional to the weight, and you could calculate the number from that :~)

maxklein 16y ago

The best way I could think of to actually use the iPad for this would be have a person lay his arm (including wrist) on it. The iPad can use the touch sensitive surface to measure how thick his wrist is and how thick his arm is, and then guess his weight. Using an accelerometer would likely be a worse user experience than just stepping on a scale, but a system where the iPad actually measures your body fat could be easier to use. However, it will likely not be very accurate. Perhaps if one were to set a reference weight at the start, and it just measures delta using the touch screen? Using the accel, a possibility is to see how close a person can swing the iPad towards his body. I assume that this would change dependent on the amount of fat around his arms. A common place people gather fat is on their thighs - thin people often have space between the legs and heavier people not as much. Also a possibility, even if a not very clever one.

nosse 16y ago
"Using the accel, a possibility is to see how close a person can swing the iPad towards his body." http://library.thinkquest.org/C003763/index.php?page=planet08 http://library.thinkquest.org/C003763/index.php?page=planet0... So it would be possible to give an estimate of upper body weight if a person would swing the iPhone with hand straight. It could give the body mass as a multiple of the hands mass. It would be easy to cheat though.

pmjordan 16y ago

What about a dumb add-on mechanism which acts as a cradle for the tablet and which tilts it at an angle depending on the downward force? That was my first thought, anyway. I'm sure the concept (accelerometer = orientation sensor) can be refined.