Strange behavior of mintyboost

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adafruit
 
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Re: Strange behavior of mintyboost

Post by adafruit »

Oby One wrote: How should I treat your affirmation ? It is said on Minty Boost compatibility webpage that my device is supported. Now it's not ? I would expect a more professional approach... in which adafruit is trying to investigate why the mintyboost doesn't fulfill it's specs. Once again I quote from your site: New In Version 3: Provides 500mA @ 5V, tested ..... If the mintyboost was giving out 500ma and 5Volts... I wouldn't have a problem. Trust me the usb from my computer is giving exactly 5V and 500ma ...and my phone doesn't have a problem with that. The second problem would be the very very low 20% efficiency. So how about we try to seek out the problems of my device?
hi oby,

other customers have this product working with your specific phone, it's possible that the phone charging method has changed recently - apple does this all the time, other cell phone oems do this as well. we think we've tried our best to assist you, please review the suggestions we've made, if you're unable to get it working or you're unhappy with the support we've provided please feel free to send the unit back for a full refund.

thank you,
adafruit

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mojo
 
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Re: Strange behavior of mintyboost

Post by mojo »

I think Adafruit deserve some slack here. The basic problem is that Apple are asshats and Adafruit is far from alone in having problems with their products.

On the one hand everyone wants a shiny iPhone 4, a device so advanced it is incompatible with primitive human hands. There is a lot of pressure to support it and if you don't it makes your operation look a bit "small time" when all the well known brands do. Unfortunately getting support officially means paying vast sums of money to Apple, and even they they will break your products with every new version of the device. A friend of mine bought some really expensive speakers with a dock for his iPod, then get an iPhone 3G and found that despite the connector being the same it was incompatible. The manufacturer's only comment was "buy some new speakers". IIRC it was Altec Lansing but don't quote me on that.

So basically Apple go out of their way to screw their customers. It is after all the customers who loose out in the end because their perfectly good but one generation out of date hardware stops working so they have to buy new chargers, new data cables, new docks etc. They also get less choice because Apple locked out many manufacturers like Adafruit. I own an iPod 3rd gen but will never, ever buy another Apple product because of their behaviour. It isn't that good of an MP3 player, much better with Rockbox in fact.

Get an Android phone and enjoy the freedom and cheap peripherals, or pay the Apple tax.

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

Lol
HTC desire is an android phone

All this thread you thought HTC desire comes from apple?

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

Hi,
I don't want a full refund .... I just want to make the device work properly and with your help I will succeed.

A friend, who has a more professional multimeter, helped me in measuring phones consumption and device consumption.

I will try to summarize in the bellow picture my findings.

How to read. for example in reading A) the phone was plugged in Pc-Usb port and the charging mode was Ac mode and the measured current was 400 ma or 0.4 Amps
Ac mode= the 2 data cables where joined and the phone believed it was in the Wall Ac charger

All this readings were made using a test usb cable ...the amper-meter was placed between the power source and the phone.

As you can see this table tells us that the phone is drawing between 0.36 and 0.5 Amps ... This is a normal charge mode for Htc Desire.
I also tested a Htc Hd2 and got similar readings.... proving once again that the phone behaves normally.
Attachments
All the readings from this picture were taken in the cable that connects the phone to the power source
All the readings from this picture were taken in the cable that connects the phone to the power source
1.jpg (28.34 KiB) Viewed 3599 times

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

In the second test I put the amper-meter between the mintyboost and the battery-pack trying to find out how much power is the mintyboost drawing.

As you can see in the attached image the mintyboost is drawing 0.68 Amps while in Usb mode and 1.3 or 1.8 Amps while in Ac mode.
The current consumption is very very high ... and that explains the battery pack lasting such a small time.

With this new data I have proven once and for all that the problem is somewhere in the mintyboost.

Now I please ask you to help me find out exactly where is the problem.
Attachments
All readings were taken between mintyboost and the battery pack.
All readings were taken between mintyboost and the battery pack.
2.jpg (23.35 KiB) Viewed 3599 times

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adafruit_support_bill
 
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Re: Strange behavior of mintyboost

Post by adafruit_support_bill »

What was the voltage of the battery pack?

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

5.7 volts

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adafruit_support_bill
 
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Re: Strange behavior of mintyboost

Post by adafruit_support_bill »

That is too high. Please read the Batteries section of the documentation and try again with a suitable power source.
Detailed guidelines - Voltage Requirements
The Mintyboost converts a low voltage to 5V USB standard. Because of this the first thing you must be aware of is that you cannot put a higher than 5v battery on the inputs to the circuit. If you do, it could damage the kit. So make sure your battery unput is always below 5V. Do not use 9V batteries under any circumstance!

Another important thing to realize is that the chip inside the MintyBoost also has a minimum voltage requirement, which is 2V. So do not try to run it off of a single AA battery or similar.

Your best bet is to keep the battery input between 2V and 4.5V. Under 2V, the chip wont work, above 4.5V the chip becomes less efficiant (for extremely technical reasons that we won't go into right here) and above 5V it will not be able to keep the voltage at a steady 5V

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

The same thing happened when I tried with 3Volts. Don't you remember?

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adafruit_support_bill
 
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Re: Strange behavior of mintyboost

Post by adafruit_support_bill »

There were no current measurements with a 3v supply.

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

No, I didn't make the current measurements with the 3V supply because minityboost behaved in the same way.
I don't see the point in repeating all of the above tests when it is clear that the main result will be the same.... I will get a 50% charge. I will get the same very low efficiency.

If you tell me what new information I will obtain by repeating the tests.... I will do them again tonight.

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adafruit_support_bill
 
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Re: Strange behavior of mintyboost

Post by adafruit_support_bill »

The measurements may well agree with your expectations, and that is not a bad thing. But In engineering, we prefer to work with real data when we can get it.

A 50% charge from 4 cells is similar to what others are reporting for their Android phones.
One user in that thread has reported that replacing a (possibly heat damaged) resistor has improved efficiency somewhat.

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

very well...
I will first do the new readings for 3V and then try to see what resistor is causing problems.

After reading that other users have the same 50% charge from their mintyboost...I am more relaxed... because if other users have the same problem.... I feel that I will get to the bottom of this.... and solve it

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

1.jpg
1.jpg (72.33 KiB) Viewed 3764 times
Ok I finally took the measurements.
I wanted to do a wide range of voltages so I started with 2 Volts and ended up with 5.2 V
The current consumption of mintyboost can be seen in the last column.

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oby_one
 
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Re: Strange behavior of mintyboost

Post by oby_one »

3.jpg
3.jpg (29.18 KiB) Viewed 3817 times
I also made a nice graph
Here you can see in a more visual way how the current consumption increases as the supplied voltage rises.
I am sure it should be exactly the opposite, meaning the current should decrease as you put in more volts into mintyboost...because it has to raise the voltage less and less.

The red line of 0.41 Amps is the actual phone consumption
The yellow doted line is just an average of the amps consumption.

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