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Posts: 227 | Thanked: 51 times | Joined on Feb 2006
#1
Ok, the first must have accessory is a spare charger for the office.

Nokia has an "adapter" on their coming soon page:
http://www.nokiausa.com/770/1,7841,acc:1|accCategory:20,00.html

The interesting thing is it says it is compatible with the ACP-7U (the older style big wall wart) and the ACP-12U (slimmer wall wart that came with my 6620). The 7U puts out 3.7 Volts, the 12U puts out 5.7 Volts. The actual charger that came with the 770 puts out 5 Volts.

So either the 770 can charge with a wide range of input voltages or their little adapter has some kind of DC level shifting built in.

Just curious.

Has anyone found a source for a barrel connector that matches the power connector? I tried a couple of local electronics places and they both carried barrel connectors but none that small. I'm building a powered USB hub / cradle and would like to make it charge the 770 as well but I'm not going to cut my only power cable to make it work.

David
 
Posts: 1 | Thanked: 0 times | Joined on Feb 2006
#2
Nokia has switched to use smaller power connector in newer devices, but power levels has stayed the same.

There is an adapter that chages the old bigger connector to smalles one so you can use all the old chargers with new phones and 770.
The part is CA-44. I got mine with my N90 phone and looking for another one.

What was suprizing that 770 sales package did not include this small, but still very helpfull, piece of hardware.

/JariK
 
Posts: 6 | Thanked: 0 times | Joined on Jan 2006
#3
I've used several Nokia chargers with the adapter, ranging from 3.6 to 5.3 volts. All worked fine. originalwireless.com had it in stock.

Last edited by RichardK; 2006-02-05 at 21:42.
 
thoughtfix's Avatar
Posts: 832 | Thanked: 75 times | Joined on Dec 2005 @ Phoenix, AZ
#4
The power plug that came with my tablet says it puts out 5v at 850 mA. Sounds like a USB splice is in order.
 
Posts: 227 | Thanked: 51 times | Joined on Feb 2006
#5
Originally Posted by thoughtfix
The power plug that came with my tablet says it puts out 5v at 850 mA. Sounds like a USB splice is in order.
I'm on the same page... I've got a translucent cased Belkin powered USB hub. I can see the 7805 sitting on the board. I want to turn the hub into the base of a powered cradle. Just slide the 770 in and have it charge and provide USB host capability.

But I'm not about to slice open my one wall wart so I can cannabilize the power plug. I guess I will have to pay $7 each for those adapters from old style to new style Nokia power plugs.

David
 
Posts: 14 | Thanked: 0 times | Joined on Aug 2006
#6
Has anyone considered putting leads directly onto the 770's internal battery to power the USB channel? Would this work or would there be insufficient power remaining for the device?
 
Posts: 125 | Thanked: 1 time | Joined on Aug 2006
#7
Originally Posted by Wesley
Has anyone considered putting leads directly onto the 770's internal battery to power the USB channel? Would this work or would there be insufficient power remaining for the device?
Seemd the discussion shifted in direction.

It is only between 3.7-4.2v so you really don't have what it needed.

However, since OTG supports cable based selection with the mini B connectors (in addition to HNP) , I wonder if it would automagically work with the right adapter. I haven't taken the time to test it.

It is just easier to steal a double stacked USB connector from an old motherboard, tie the lines and use the 7805 (or zener) with a 9volt for a compact solution.
 
Posts: 79 | Thanked: 1 time | Joined on Nov 2005
#8
Originally Posted by Luna
However, since OTG supports cable based selection with the mini B connectors (in addition to HNP) , I wonder if it would automagically work with the right adapter. I haven't taken the time to test it.

It is just easier to steal a double stacked USB connector from an old motherboard, tie the lines and use the 7805 (or zener) with a 9volt for a compact solution.
You should probably do a search of the discussion archives; you'll find lots of people have been playing with this stuff in the past.

To summarize:

The USB chipset in the 770 is capable of host or device mode, ie: OTG.

However, actual proper OTG support would require both an OTG connector in the 770, and that the 770 supply 5v power to its USB port.

Unfortunately, it does neither.

If you want to use the 770 as a USB host, you'll need to provide 5v _to_ the 770, _regardless_ of whether the device you're hooking up has power or not. In other words, AFAIK the 770 itself _needs_ 5v to turn on its USB.

Numerous people have built various kindes of devices to supply 5v to the 770. You can build your own using a regulator, or you can use a weird dual-headed USB power cable designed for hard drives to suck power from some other computer.
 
Odin's Avatar
Posts: 207 | Thanked: 3 times | Joined on Jun 2006 @ Texas
#9
Originally Posted by Wesley
Has anyone considered putting leads directly onto the 770's internal battery to power the USB channel? Would this work or would there be insufficient power remaining for the device?
I have heard people lament the fact that Nokia did not include host mode so that people could plug USB devices in. The simple reality is that it would create too much load on the power system, which is fairly much strapped as it is between BT and Wi-Fi.

The very best "workaround" is to simply supply external power to any devices you want to run. There are many, many ways to do this. I found that the simplest solution was to modify an iPod Shuffle battery pack. The pack uses two AAA's and is very, very efficient (never gets hot like those 7805 regulators with a 9 volt) and very, very compact. Also, after the mod it looks like something you might by rather than a kludge--for what it's worth.
 
Posts: 125 | Thanked: 1 time | Joined on Aug 2006
#10
Originally Posted by bhima
You should probably do a search of the discussion archives; you'll find lots of people have been playing with this stuff in the past.

To summarize:

The USB chipset in the 770 is capable of host or device mode, ie: OTG.

However, actual proper OTG support would require both an OTG connector in the 770, and that the 770 supply 5v power to its USB port.

Unfortunately, it does neither.

If you want to use the 770 as a USB host, you'll need to provide 5v _to_ the 770, _regardless_ of whether the device you're hooking up has power or not. In other words, AFAIK the 770 itself _needs_ 5v to turn on its USB.

Numerous people have built various kindes of devices to supply 5v to the 770. You can build your own using a regulator, or you can use a weird dual-headed USB power cable designed for hard drives to suck power from some other computer.
I take it you didn't read my whole post as i document the easiest power injector. As for otg, vbus is actually monitored all the time,just watch the tahvo /vbus value when you supply power. what this pbly means is it is one all the time but host is partially implemented in the driver. Btw, the connector appears otg compliant but anyways otg has two techniques to establish host: Grounding of the pin or HNP(host negotiation protocol)


ps odin, switching rather, switching rather than linear 7805 variants are out but i just use 4 AA's or
a y usb cable included with a mini hub i got at best buy for 25 buckss than linear 7805 variants are out but i just use 4 AA's or a y usb cable included with a mini hub i got at best buy for 25 bucks
 
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