iPhone 3Gs does not work with my minty boost 2.0

[sreney]

I have been using the Minty Boost with my 3G with no problems but now when I plug in the 3Gs I get the little charging icon and the beep like it is connected to a charger but then immediately get a warning that says "charging is not supported with this accessory" and I also notice the minty boost making a low hissing sound that it did not do with the 3G.

Any thoughts or opinions?

[adafruit]

it sounds like apple got tired of people using 3rd party chargers instead of Apple(tm) Brand(r) iPhone(c) Chargers
ill see if i can track down a 3Gs and try it out or maybe someone else in the forum can :/

[stiell]

I just assembled mine tonight and it seems to "kind-of work". If I plug it into the outlet adapter that came w/ the 3gs, then switch the usb plug to the MintyBoost v2.0, it works (the 3gs makes the recharge sound and shows that it's plugged in and charging).

[ryanjmclaughlin]

I just tried mine with the iPhone3GS and it is not working, getting "This accessory is not supported for charging"

Is it just a simple change of resistor value?

[adafruit]

ill check it out later but it may be a pain to fix.

[revmitcz]

Oddly enough, when I first built it, I plugged it into my 3GS and had zero problems whatsoever. Once I actually put it into the altoids tin, however, I've had a few times where it will give me the message about the charging being incompatible w/this accessory.

However, simply unplugging the USB side of the equation and doing it again works 95% of the time. The other 5%? I just unplug it and plug it in again. As of yet, it hasn't not worked if I did that once or twice. Even with a cheapo 3rd party iPod adaptor (seriously, I bought it for $6 at a gas station).

So, maybe there's a small short circuit taking place that I'm unaware of, that is somehow intermittent. Might be the same situation with yours. (and for the record, I'm using the Minty 2.0 kit)

[drmellow]

It's working for me. Version 2.0 of the kit, that I built a month ago, no mods, mounted in a tin. iPhone 3GS that I bought last week. Energizer Advanced Lithium batteries. I'll experiment some more with other flavors of batteries and various battery charge levels on the iPhone over the weekend.

[crunch777]

Thanks for a fun project!

I can also report that it will not charge my 3Gs. I tested on a 3G and it works fine but again on the 3Gs, negative. I tried disconnecting the cable from both ends and no change. Only once, when I removed the batteries and retested did it work, but that was only one time.

I tested my output and it looks ok. I'm using the 100k resistors and believe all my soldiering is solid. I realize this project is not intended for iPhones due to their battery size but I'm hoping to utilize a larger Li-Poly once I'm past this hurdle.

Any assistance is greatly appreciated.

Regards

[oata]

Hi all,

Same here, it is not working with my 3GS. Here is my story:
1. On initial test before puting to the tin is was working.
2. It won't work in the tin at all.
3. Yesterday I was testing and checking the voltage both on the MintyBoost and original charger and I was getting exactly the same 5.1V
4. While doing this I touch the contacts and original charger won't show any output (0 V) but conneting to the iPhone made it charge it again.
5. Did the same with MintyBoost and it started to charge the phone.
6. I woke up today with sense that all is well and I can take MintyBoost with me on the trail and was surprise when connected to mIntyboost to see same error "charging is not supported with this accessory". This time touching the contacts did not help.

Hope this may help to solve this mystery and come up with some solution.

Regards,
A.T.

[oata]

I checked the voltage on the pins:
with MintyBoost
5.1V
D+ - 1.8V
D- -1.8V
Apple charger:
5.1V
D+ 2.5V
D- 1.8V

Can somebody confirm that you are getting the same voltages? or how can I boost D+ to 2.5V?

Thank you,
Arunas

[michelef]

Would adding a 75k resistor between D+ and ground work?

[crunch777]

I checked voltages on the data ports and they both read 2.82 on mine. As I mentioned in my earlier post, the minty boost is not charging the 3Gs. Anyone have any thoughts?

Thanks

[crunch777]

From: http://pinouts.ru/Devices/ipod_pinout.shtml

To charge an iPhone 3G / iPod Touch 2nd gen, usb data- (25) should be at 2.8v, usb data+(27) should be at 2.0v. This can be done with a few simple resistors: 33k to +5v (23) and 22k to gnd(16) to obtain 2v and 33k to +5v and 47k to gnd to obtain 2.8v. This is a "notification" to the iphone that it is connected to the external charger and may drain amps from the usb.

I'm assuming that D+ and D- in the minty boost are being taken from the battery feed which can be anywhere from 2.4v to 3 depending on the batteries used. I'm only a beginner on circuit diagrams so can someone verify this? Does it make more sense to pull that power from the nicely regulated 5v? So if my assumption is correct, and our feed to D+ and D- are from the 3v battery feed, that the suggestion above wouldn't work as they calculate the resistors based on a 5v feed? Would anyone here be able to tell me how best to modify the minty boost to get 2.8v to D- and 2v to D+?

I happen to have a store bought mobile battery pack that works with my iPhone 3Gs. I measured the data pins and get 2.8 and 1.99 so I think my hunch is correct. If we can get the data lines on the minty boost to those we should have success.

Thanks in advance.

[adafruit]

you should try it, previous iphones were less picky

[crunch777]

you should try it, previous iphones were less picky

Thank you, but was this directed at me or another poster? I would personally love to be able to figure this bit out but come up short on a few things as mentioned in my last post.

Are the data lines power provided off of the 3V battery feed or the 5V?
What resistor configuration would deliver 2.0V and 2.8V on those pins based on 3V and 5V?

Thanks