USB Charge Booster - Passthru DCP Enumerator [Final]

Then what’s that cable coming out of your shorts?

Gotta have a ground :stuck_out_tongue:

You stood still near OL to long. Something like this was going to happen eventually. Looks like he has perfected the application perfectly.

Maybe this is related to the ideas in this thread. I just noticed that my iPad will not charge at the 2A rate when a Charger Doctor is inserted in it’s path. Charges at a maximum of 1A. Would there be an easy mod for this or a whole new design?
I have ordered a couple of other “Charger Doctor” type devices to see if they will allow a 2A pass thru.

If the charge doctor passes data thru it, then the iPad is charging from the signature coming from the device it’s plugged in, if not the charge doctor might have the data pins shorted…that is the one signature that should charge at a max of 1A on most devices but won’t ever charge more than that.

You can actually take a regular “data” USB cable, open it up, then short the D+ and D- wires (the green and white wires inside the cable) going to the connector that plugs into the devices needing charging (usually the USB micro male plug) it will charge at up to 1A and NOT ever pass data [It becomes a dedicated charging cable]


My module I made, and the IC on it will send the iPad signature back (it has 6 different charge signatures it can send out) to the device and as long as the charging port it’s plugged into can deliver 2A or more, the device will charge at that (with losses thru the cables of course) [the chip autoranges and will change because it senses the input voltage, if it sags because the charging device pulls to much, it will change to a little slower rate until the input voltage comes back up to within tolerances of the approx 5vdc charge level]

Probably because the voltage it to low, i.e. the "Charge Doctor" has to high internal resistance compare to the voltage from your charger.

This is something I test in my reviews of usb meters.

The Charger Doctor will pass 2A to non Apple devices but only 1A to an iPad. This with an official Apple 2A wall charger.
So would this device inserted after the Charger Doctor and before the iPad allow a 2A charge rate?

Sweet,! I hadn’t picked up that particular detail from the datasheet.

Ok, got boards in, got em put together, tested, on a data downstream port get .45A, thru the charge booster on the cable, first off computer doesn’t see device, and it pulls .75A, (correction, moved to another port, seeing .94A) the cord I have has alot of loss

Updated OP, will more than likely do a giveaway for one of em, with only 2 small SMD items on board, it’s a really easy and cheap DIY anyway

I will say this, the pads on the female USB part are very narrow, I might fix the component library file for the board even though it’s in the sparkfun repository

It should, the tablet my wife uses pulls 1.67A out of the dual port DCP board I made a while back

I should have updated that statement. I have since learned that even a quality non Apple cable (Belkin) can cause problems with trying to draw >1A. No such problems with Apple cables. Also this problem only shows up when the iPad is below 40%.
The Charger Doctor had nothing to do with what I was experiencing.
As if things aren’t difficult already.

At this time do not order these boards, I have smoked 2 IC’s on two separate boards, the dual boards are working fine, but these single boards are not. Pulled the project until I can troubleshoot and correct

that sounds like a proper Oshpark project (good luck troubleshooting)

ok, updated the design (actually made it smaller!)…ordering and will build them out…this time instead of using a 1uf cap (spare off time caps for drivers), going to order .1uf

I also am going to go ahead and build the componentless DCP charge/USB wrapper adapter, only the USB in, and USB out jacks needed, will only charge at 1A (due to shorted data pins), but it will be a VERY inexpensive USB wrapper at least

Tested, good to go

So what’s it look like and what do they provide now? Can they do 2 amps?

Yes, if the output port can support 2A, this board will put the correct charge pattern for it being able to pull up to 2A, the most I got thru one of mine due to cable loses was 1.67A to my wifes tablet

Image (sorry it’s such a lousy picture)

Top board is the DCP Enumerator w/ IC and capacitor, Bottom board is component less, only USB jacks, data pins are shorted on output side (will only be able to charge at up to 5W or 1A max [bottom prototype also had a via “stop” problem and the via’s weren’t connected to the ground plane so no current flow, I had to jumper the pins, release board has the fix on it)

Either way, both of these act as a USB wrapper and will prevent juice jacking or allowing data to flow to any unknown USB port

Thread on component less board

bump

because of this!! Seriously??

There was a story on the local news last night about a lady that just bought a memory card from a local Walmart (in a sealed package). It came pre-loaded with 8 GB of porn.

And don’t forget about the clothing irons and teapots with a wifi card in them that broadcasts malware. They also have a microphone in them…

Oh, and Chinese Android devices that come pre-loaded with un-removeable malware:

I can get boards from Oshpark? And parts where?
I’ve got a decent temp-controllable heat gun in the mail, so, can venture into mounting small parts.

I’m starting to think one of these should be super-glued into any public USB charging station!