iPhone scale application?

[Crank Lucas]

no really Im wondering now I mean the touch screen is pressure sensative, so how hard would it take to have a application (lets call it iScale:)) that can measure whatever you put on it in grams?

you know, just to measure some small materials ;)

so waddaya think?

[FunkyMonkey]

Not possible. The touch screen can't sense how much weight or pressure you are applying to the screen. It only knows when you are touching it and where. I have thought of this before and I think it would be awesome if it worked.

[GetAudiHere]

That would be awesome! They do make fake iphone/ipod touch scales.

[f60]

iweigh in itunes store. Works perfect.

[Dr. Cabrera]

the iPhone does not work on pressure, it works on capacitance ( your finger distorts the electrical field on the surface of the iPhone)

Google it if you don't believe me

[questrillion]

iScale is possible, without external hardware or a strain gauge.

I am working on it right now.

You will be able to weigh objects by placing on your iPhone, from 1/2 ounce to around 1 lb-2 lb.

...its not a pendulum...not a balance...not a touch screen.

Assuming I can get Apple to accept it, look for it soon.

[chrmjenkins]

iScale is possible, without external hardware or a strain gauge.

I am working on it right now.

You will be able to weigh objects by placing on your iPhone, from 1/2 ounce to around 1 lb-2 lb.

...its not a pendulum...not a balance...not a touch screen.

Assuming I can get Apple to accept it, look for it soon.

I'm skeptical as to how this would work. The only thing you have to work with is area of displacement since the capacitive sensors are binary in nature.

Resistive touch screens are pressure sensitive, however. You would be able to weigh small things with those.

[questrillion]

I understand your skepticism.

I did not know if the method I am using would work or not until I wrote the code and tested.

I hope to have it finished and fully tested in the next 5-10 days.

[cellocello]

I understand your skepticism.

I did not know if the method I am using would work or not until I wrote the code and tested.

I hope to have it finished and fully tested in the next 5-10 days.

HA!

So you're assuming this would work. No code or nothing yet, eh?

[renewed]

iScale is possible, without external hardware or a strain gauge.

I am working on it right now.

You will be able to weigh objects by placing on your iPhone, from 1/2 ounce to around 1 lb-2 lb.

...its not a pendulum...not a balance...not a touch screen.

Assuming I can get Apple to accept it, look for it soon.

That will be a hit in the underground if you get my drift lol :p

[renewed]

HA!

So you're assuming this would work. No code or nothing yet, eh?

I think it could work, just have something on screen, such as a giant touch button, that measures the pressure being applied to the touch portion under the glass. ;)

[cellocello]

I think it could work, just have something on screen, such as a giant touch button, that measures the pressure being applied to the touch portion under the glass. ;)

'Cause that is, after all, exactly how the iPhone works ;)

No wonder I need to press so hard in some apps!

[CalumC]

Are you ok with people guessing at it questrillion? I've got an idea as to how you might be doing it but i'm sure that if its something you're making money with then you'd rather keep it shtum and i'm not out to stop that, even if this is a public forum!

[chrmjenkins]

I think it could work, just have something on screen, such as a giant touch button, that measures the pressure being applied to the touch portion under the glass. ;)

The iPhone's touch mechanism is not analog. It can only sense the presence of something, not the degree of pressure.

[cellocello]

Are you ok with people guessing at it questrillion? I've got an idea as to how you might be doing it but i'm sure that if its something you're making money with then you'd rather keep it shtum and i'm not out to stop that, even if this is a public forum!

Unless he's measuring fingers (and by 'measuring' I mean detecting taps); he's not doing anything.

[bluenoise]

Here's how it would work:

1. Determine how much distributed weight the glass can hold before it shatters.
2. Run the app and then load the screen with item(s) to be weighed.
3. If the screen does not collapse, the item being weighed is lighter than the predetermined weight. If it caves in, it weighs more than the predetermined weight.

Disclaimer: This app may only work once and may void any factory warranties.

[questrillion]

I works...meaning that changing the weight changes the output in a predictable manner. It is very non-linear, but it can be characterized and calibrated to output the actual weight.

It is coded, but I have not coded the UI...I have only coded the measurement portion.

It am still testing out the calibration methods.

Yes...underground will LOVE it, but it will need to be very accurate for that. Else, it will be good for postal scale, diet scale, but not good for herb scale.

If it provides decent repeatability, Apple will pass it, else, it will go to the jail break market.

[renewed]

The iPhone's touch mechanism is not analog. It can only sense the presence of something, not the degree of pressure.

Good to know. I guess its like kicking an appliance to make it work.. sometimes i have to push really hard to make that darn SMS load properly in 3.0 ;)

Good to know guys, I guess I assumed even though the applications on the iPhone work by touch recognition, not pressure, there would be some way to create an application that can tap in and assume pressure and not just touch. But of course you know what they say about ASS-U-ME.

[cellocello]

I works...meaning that changing the weight changes the output in a predictable manner. It is very non-linear, but it can be characterized and calibrated to output the actual weight.

It is coded, but I have not coded the UI...I have only coded the measurement portion.

It am still testing out the calibration methods.

Yes...underground will LOVE it, but it will need to be very accurate for that. Else, it will be good for postal scale, diet scale, but not good for herb scale.

If it provides decent repeatability, Apple will pass it, else, it will go to the jail break market.

I'm curious how your iPhone detects anything other than fingers. Can you elaborate a bit on that?

I mean ... Mine won't even detect leather gloves, let alone random objects like envelopes or herbs.

[bluenoise]

I works...meaning that changing the weight changes the output in a predictable manner. It is very non-linear, but it can be characterized and calibrated to output the actual weight.

It is coded, but I have not coded the UI...I have only coded the measurement portion.

It am still testing out the calibration methods.

Yes...underground will LOVE it, but it will need to be very accurate for that. Else, it will be good for postal scale, diet scale, but not good for herb scale.

If it provides decent repeatability, Apple will pass it, else, it will go to the jail break market.

Given that the screen on my iPhone is completely unresponsive to paper and most dry foods, I doubt it's going to make a decent postal or diet scale.

[questrillion]

I'm mum until I run it to ground, win or lose.

But, if its turns into a dead end, I'll drop my method out here and maybe someone can improve on it.

[cellocello]

I'm mum until I run it to ground, win or lose.

But, if its turns into a dead end, I'll drop my method out here and maybe someone can improve on it.

It's not really about that.

I mean, you get how the iPhone screen works, right? How is detects presses and what not?

[questrillion]

Yes...I understand touch detection on the iPhone.

I should have the curve tonight. Then its all about calibration (can it be calibrated to any iphone or is the curve specific to each unit)

Regardless, it is possible. I am doing it. But, it remains to be seen whether or not it can be distributed.

[chrmjenkins]

Good to know. I guess its like kicking an appliance to make it work.. sometimes i have to push really hard to make that darn SMS load properly in 3.0 ;)

Good to know guys, I guess I assumed even though the applications on the iPhone work by touch recognition, not pressure, there would be some way to create an application that can tap in and assume pressure and not just touch. But of course you know what they say about ASS-U-ME.

Yeah, the touch detection is what makes cap screens good for multi-touch. Just a cap array and each cell reports a touch independently.

For a resistive screen, you have a resistive gradient behind the screen. That is to say, each touch point will use trigger a specific resistance, which can be extrapolated by means of measuring current. If you want to do multi-touch, you have to consider that there are many ways to get the same answer, so it becomes a challenge. That is why the G1 has been slow to get it, and at the hands of independent developers.

Based on questrillion's knowledge built into his responses, I'd say he has something going.

[cellocello]

Yes...I understand touch detection on the iPhone.

I should have the curve tonight. Then its all about calibration (can it be calibrated to any iphone or is the curve specific to each unit)

Regardless, it is possible. I am doing it. But, it remains to be seen whether or not it can be distributed.

*shrug*

Ok homie.

[ser0pro]

BUMMMMMMMMMMPPPPPPPPPPPPPP!!! anything new going on wit this??? i want to see a more legit scale than the iscale... which only weighs 5 grams?? :confused: nothing more, nothing less... plus it doesnt work for Iphone 2.x..... BS!!!!!!!! I WANT YOUR APP! make it exclusively for jail breaking too, screw Apple... please email with any updates! its a must! thank you!

[cellocello]

:rolleyes:


Anyhooo .... Ya, OP. What IS going on with your scale app? ;)

[Mad Mac Maniac]

yes mr questrillion. I want to see your application.

this is the ONLY thread he has posted in on MR to date...

[crandel]

If you use the phone as a balance scale, i.e. use the accelerometer instead of touch to measure change in weight. You would have to balance it on your finger or something, exactly in the middle of the phone and then see how much whatever you are weighing tilts the phone. I have a feeling this is the curve he was talking about, accelerometer tilt to weight displacement. If so, it would be a terrible app and really annoying to use.

[ser0pro]

If you use the phone as a balance scale, i.e. use the accelerometer instead of touch to measure change in weight. You would have to balance it on your finger or something, exactly in the middle of the phone and then see how much whatever you are weighing tilts the phone. I have a feeling this is the curve he was talking about, accelerometer tilt to weight displacement. If so, it would be a terrible app and really annoying to use.

This already exist.... The Iscale... Iphonescale.com check it. it only works for 1.x firmware, so im already SOL. but from the video i saw it was accurate, but it only weighed up to and nothing under 5 grams... so its not that tight. i would build a leveler for it instead of my finger. its still worth it...

[Dr. Cabrera]

can we please close this thread

[cellocello]

This already exist.... The Iscale... Iphonescale.com check it. it only works for 1.x firmware, so im already SOL. but from the video i saw it was accurate, but it only weighed up to and nothing under 5 grams... so its not that tight. i would build a leveler for it instead of my finger. its still worth it...

Damn is that dumb.

balancing the iPhone on your finger then using the tilt as the "scale"? aaahhh hahahahha

[Ron21]

umm it has already been said, the iPhone does NOT have a pressure sensitive screen. That is why it does not work with gloves on. The iPhone screen uses capacitive technology.

"Capacitive
A capacitive touchscreen panel is coated with a material, typically indium tin oxide, that conducts a continuous electrical current across the sensor.[3][4] The sensor therefore exhibits a precisely controlled field of stored electrons in both the horizontal and vertical axes - it achieves capacitance. The human body is also an electrical device which has stored electrons and therefore also exhibits capacitance. Capacitive sensors work based on proximity, and do not have to be directly touched to be triggered. It is a durable technology that is used in a wide range of applications including point-of-sale systems, industrial controls, and public information kiosks. It has a higher clarity than Resistive technology, but it only responds to finger contact and will not work with a gloved hand or pen stylus unless the stylus is conductive and transmits the user's capacitance. Capacitive touch screens can also support Multitouch. Examples include Apple Inc.'s iPhone and iPod touch, and HTC's T-Mobile G1."

http://en.wikipedia.org/wiki/Touchscreen

[RiceRacerDX]

Show me where in the specs where you read that the iPhone has a "pressure-sensitive" screen. It does not have a pressure sensitive screen. It has a touch sensitive screen.

I bet you're one of those people at Wal-Mart that presses really hard on the "Credit" option when you pay with your card on their machine and cuss at it when you don't know why it doesn't respond. Touch sensitive...not pressure sensitive buddy.

Don't blame the machine. Blame the user.

[Aaleck]

Then there'd be tons of posts "Help! I was using the scale application and stood on my phone to see how much I weigh and broke it" :(

[milani]

I think it could work, just have something on screen, such as a giant touch button, that measures the pressure being applied to the touch portion under the glass. ;)

I don't think the iPhone measures pressure at all - as has been said several times in this thread, although I can't say I know for sure...

[mikeinternet]

I think questrillion is messing with you guys. This is not possible.

[questrillion]

OK...I can now tell you the method.

The method was to measure the z-component of the accelerometer while the vibrator was running.

This gave a curve that could be characterized according to how much weight was placed on the device.

It works well between 3-5 pounds, but is useless below that.

Everyone wants grams and ounces...not feasible with this method.

[Andruw91]

Why does this thread sound like it is appealing to drug dealers most of all?

[Ding.Dong]

OK...I can now tell you the method.

The method was to measure the z-component of the accelerometer while the vibrator was running.

This gave a curve that could be characterized according to how much weight was placed on the device.

It works well between 3-5 pounds, but is useless below that.

Everyone wants grams and ounces...not feasible with this method.

That actually sounds like a pretty ingenious solution, but I doubt it would be very accurate. I hope you didn't spend too much time developing the program.

[afireintonto]

no really Im wondering now I mean the touch screen is pressure sensative, so how hard would it take to have a application (lets call it iScale:)) that can measure whatever you put on it in grams?

you know, just to measure some small materials ;)

so waddaya think?

why in grams??
this sounds like you're buying drugs

[Andruw91]

Why does this thread sound like it is appealing to drug dealers most of all?

why in grams??
this sounds like you're buying drugs

That's what I was getting at

[lostprophet894]

OK...I can now tell you the method.

The method was to measure the z-component of the accelerometer while the vibrator was running.

This gave a curve that could be characterized according to how much weight was placed on the device.

It works well between 3-5 pounds, but is useless below that.

Everyone wants grams and ounces...not feasible with this method.

I can't really think of many 3 - 5 pound objects I would be needing to weigh...

Very cool concept though.

[The Californian]

Bummer... I guess drug dealers will have to stick with the $4.99 digital gram scales at Walmart instead of a $500 phone.

[Dr. Cabrera]

actually this concept is so flawed it would never work


a) only hard, stable surfaces would work
b) these motors are not calibrated
c) this would kill your battery pretty quickly

[The Californian]

But he's not talking about using the touch screen ... There's no way that would work since the touch screen deals with electrical conductivity and not pressure ... He's talking about using the accelerometer.

[t0mat0]

But he's not talking about using the touch screen ... There's no way that would work since the touch screen deals with electrical conductivity and not pressure ... He's talking about using the accelerometer.

It's an interesting concept. A good set of scales should have a standard weight or two. You could calibrate the vibrate if you looked at it and found it was consistent.

Maybe you'd need to have the iphone in a solid case, which could have the to be weight material added, and the measure how much the iPhone moves on a plumb line.

[doobi18]

The iPhone touch screen does not measure pressure - it detects interruption in the electrical field.

[egautreaux]

I heard the iPhone touch screen can measure pressure....Is it true?

[dacreativeguy]

If you developed an iPhone app that could measure weight to .00000000001 accuracy, I'd never use it. Why would I risk putting heavy objects on a $300 phone when there are dedicated scales available for $10.

[The Californian]

The iPhone touch screen does not measure pressure - it detects interruption in the electrical field.


Way to jump in at the end of the conversation and NOT read anything we've already talked about.

[doobi18]

Way to jump in at the end of the conversation and NOT read anything we've already talked about.


Way to criticise a simple and clear summary of what two pages of comments failed to properly ascertain.
Way to troll.
Way to bow to hypocrisy by condemning the perpetuation of a thread by posting a response.


//doobi18

[questrillion]

It did work, as I said, between about 3 and 5 pounds, which is worthless.

It was sensitive to what kind of surface you put it on, which is why it was not accurate below 3 pounds.

Below one pound, it was not sensitive at all.

Yes, different iphone = different motors, characteristics, etc...so you would need a calibration sequence built into the application.

If anyone can figure out how to make it better, go for it.

[Interstella5555]

It did work, as I said, between about 3 and 5 pounds, which is worthless.

It was sensitive to what kind of surface you put it on, which is why it was not accurate below 3 pounds.

Below one pound, it was not sensitive at all.

Yes, different iphone = different motors, characteristics, etc...so you would need a calibration sequence built into the application.

If anyone can figure out how to make it better, go for it.

Really the only way I'll beleive this is even remotly possible is if you post a video. Besides -
Post scale - $15.00
iPhone - $299.00 plus associated cost

If you're that hard up, get a postal scale and don't use your phone for deals.

[ebrunn]

With the 3.0 software update, expect to see a company make a scale that plugs into the dock connector.

[chrmjenkins]

Way to criticise a simple and clear summary of what two pages of comments failed to properly ascertain.
Way to troll.
Way to bow to hypocrisy by condemning the perpetuation of a thread by posting a response.


//doobi18

Get off the high horse buddy. The screen not being pressure sensitive was duly noted (and your post with big text was obnoxious), and your third point doesn't even make sense, as he didn't object to the thread continuing.

[cellocello]

With the 3.0 software update, expect to see a company make a scale that plugs into the dock connector.

Oh for sure.

I expect a lot of wacky accessories.

[Sloggs]

Search Scale Application in App Store to download an application that can weigh objects placed on the iphone screen.

[ViViDboarder]

Search Scale Application in App Store to download an application that can weigh objects placed on the iphone screen.

False.

It uses the methods described by questrillion earlier. Hardly accurate and hardly a scale. I'd be a better judge using my hand and taking a guess.

[quad64bit]

If this is so impossible, how does the guy from Bahntech do it?

http://www.youtube.com/watch?v=GtpgZCZdTjE&p=BD0FDA5CB97987A1&playnext=1&index=6

[ViViDboarder]

If this is so impossible, how does the guy from Bahntech do it?

http://www.youtube.com/watch?v=GtpgZCZdTjE&p=BD0FDA5CB97987A1&playnext=1&index=6

Likely the same way as mentioned before. Vibrating and using statistical test to measure the difference in phone acceleration with different weights present.