iPhone 3Gs does not work with my minty boost 2.0

[adafruit]

did you swap the data pins

[natevoodoo]

did you swap the data pins

Yes I tried that and that didn't help.
I did finally get it to work though!
The issue seems to be the current. I didn't have my current set high enough on the power supply.
The iPhone spikes the current draw up to 1 A to test whether it is connected to a computer or power charger.
I needed to have at least 1.02 A available from the power supply for the iPhone to accept the mintyboost charger.
Then it settles down to drawing around 300mA.
I've misplaced my battery pack so I can't test it with that. Will the batteries supply that much current?
Will drawing 1A damage the boost chip?

Thanks for your time,
Nate

[adafruit]

we've built it and it works. other users have also built it and found that it works. you could try building it and seeing if it works?

[natevoodoo]

we've built it and it works. other users have also built it and found that it works. you could try building it and seeing if it works.

Not sure what you mean. Sorry if I've irritated you. My intention was to share my experience with others and get help.
To sum up:
I did build it with the battery and different resistors but voltages within 3%. That failed.
My initial assumption was that the new firmware had made it more sensitive.
So I built a lab testing version without the battery and exact resistors and it also failed.
I pumped up the current to 1.02A and it finally worked.

[natevoodoo]

did you swap the data pins

Maybe I'm misunderstanding you. By "swap the data pins" do you mean put 2.0V on USB2 and 2.7V on USB3 instead of the reverse shown in the schematic on the FAQ? or something else?
http://www.ladyada.net/make/mintyboost/usb4res.gif

[adafruit]

did you swap the data pins

Maybe I'm misunderstanding you. By "swap the data pins" do you mean put 2.0V on USB2 and 2.7V on USB3 instead of the reverse shown in the schematic on the FAQ? or something else? http://www.ladyada.net/make/mintyboost/usb4res.gif

no problem --- phil from support here. the faq has been updated with the correct values, we've built it, it works, we use it here at the shop, other users haven't had any problems with the updated info - we suggest trying to build it

all that said, it's not officially supported by us, it's hack/mod, so please please experiment a bit - if you want an off the shelf charger there's many that "just work" but that isn't any fun . i think this thread is pretty saturated, try and build it and see how it goes.

cheers,
adafruit support

[natevoodoo]

did you swap the data pins

Maybe I'm misunderstanding you. By "swap the data pins" do you mean put 2.0V on USB2 and 2.7V on USB3 instead of the reverse shown in the schematic on the FAQ? or something else? http://www.ladyada.net/make/mintyboost/usb4res.gif

no problem --- phil from support here. the faq has been updated with the correct values, we've built it, it works, we use it here at the shop, other users haven't had any problems with the updated info - we suggest trying to build it

all that said, it's not officially supported by us, it's hack/mod, so please please experiment a bit - if you want an off the shelf charger there's many that "just work" but that isn't any fun . i think this thread is pretty saturated, try and build it and see how it goes.

cheers,
adafruit support

ok well I did build it. not sure why you keep saying that or why that isn't clear. not expecting you to "support" this hack either.
But maybe you could update the FAQ to show that at least 1.02 A are needed for it to be recognized by the iPhone. (at least with my firmware)

[adafruit]

ok well I did build it. not sure why you keep saying that or why that isn't clear. not expecting you to "support" this hack either.
But maybe you could update the FAQ to show that at least 1.02 A are needed for it to be recognized by the iPhone. (at least with my firmware)

we'll look in to that next update!

[Darkknight512]

I just read online that if you short D+ to D- the device will charge no problem. No resistors needed.

Today I also tested by MintyBoost with my friends Ipod Touch, it refused to charge. The MintyBoost is putting out 5.04 V no load on V+, and 2.20 V on both D+ and D-. This is with 2x100K resistors, both pull up's.

I will be testing this with my sisters Iphone on friday.

Edit: This is with 2 NiMh Batteries

Edit2: After reading online for the past half hour this is what I have

The iphone 3GS/ipod G3 touch expects 2.0+V on the D+ and D- pins to charge
The older ipod touch and older iphones only expected 1.25+V on D+ and D-

I also read something about the chip used in iphone chargers, it reports 2.0+V to tell the iPhone that the port is able to deliver 500 mA

While I am getting 2.2 V off D+ and D- I'm thinking maybe the voltage drops below 2V when the iPhone/iPod starts to pull 500 mA. Maybe if we just supply the D+ and D- pins with more voltage the voltage won't drop as far and the device will keep charging.

This might also be why people are able to charge off Lithium batteries, because the voltage does not drop to below 2.0V

I also use a volt meter to test the ports on my computer, it tells me that the voltage is 5 volts on the data pins when I touch the green or white wire and red to a volt meter. This makes we wonder, why don't we just connect the 5V output to the data pins? If we are trying to mimic a PC's usb port then that sounds perfectly reasonable to me.

[natevoodoo]

ran into some additional power needs problems
the original 220 uF 6.3V cap that comes with the kit did not supply enough power for the phone
so it was not recognized as compatible device
I replaced with 35V 220uF and got it to supply enough current and be recognized
however when batteries got down to ~2.4V it again would not work as it could not supply enough current when they are low

bigger cap or even higher voltage cap needed?
if so i'll need a bigger case no doubt
any thoughts appreciated

[daesuchu]

Does anyone has pictures of working Mintyboost v2. w/ iphone 3gs mod (along with 43K, 51K, 75K registors)
That'll definitely help for my bloody struggling!!!

thanks

[daesuchu]

And another quick question from two confusing schems b/w
http://www.ladyada.net/make/mintyboost/faq.html
and
http://www.adafruit.com/blog/2010/02/09 ... phone-3gs/

The first one says
USB1 (V-in):5v,
USB2 (D-): ~2.0v
USB3 (D+): ~2.7v
USB4 (GND)

and the second one changes the connection b/w USB2 & USB3

Can someone tell me which one is correct?

thanks

[adafruit]

http://www.ladyada.net/make/mintyboost/faq.html

[KA1OS]

Related to the resistor-divider network solution...
I have a 5.1V wall wart that I spliced into a USB extension cable and used to charge an iPod mini. As with the original MintyBoost, that didn't work with the iPod touch or iPhone. Thanks to the faq and discussions here, I was able to modify the original charger and get the Apple devices to work with the wall wart. Playing with the figures, I found a three-resistor alternative to match the 2.7v and 2.0v potentials necessary and which used standard 5% resistor values. These are resistors you can find in Radio Shack resistor assortments. The arrangement is shown below:

5V --- [56K ohm] -- 2.6v tap -- [15K ohm] -- 2.0v tap -- [47K ohm] --- GND

This works for the most recent generation iPod touch and the iPhone 3GS.

But there's a hitch -- When choosing the resistors, I had no idea what currents the iPods drew from the D+ and D- lines. Without a load, the taps are 2.6v and 2.0v but when attached to an iPod touch, the voltages are pulled down to 2.43v and 1.80v, respectively (The source holds at 5v - It's a 2.5A supply). Despite these drops it seems the Apple devices are still happy with the charger.

[Vertiousit]

Just wanted to report a success with the mintyboost 2.0 and iPhone 3GS!
Works with the 2x AA case as well as a 2000mAh @ 3.7v LiPo battery. On first attempt, charged my 3GS from 14% to 100%. Tested it on my old 3G and Arduino as well, both work too!

Haven't tried charging it more using the LiPo yet, but will do once my iPhone starts discharging again. If the 3GS has a 1200 mAh battery im guessing I should get 1.6 charges out of it but we'll see.

As for the D+/D- resistors, I used the (more resistant) ones supplied in the kit (forgot to record the values i got) and they seem to be doing the job just fine....
Thanks for such an awesome project!