Wednesday, 10 November 2010

iPhone mount (again)

Finally pulled my finger out and sorted my iPhone mount on my bike. I went about a week before pulling it off again and attempting to get a charger in to the waterproof case ("iDry" from Amazon/eBay) as well.

Modified iDry case on BMW GSA.
On-bike view. I use Tom-Tom and MotionX GPS apps.
Protected from the worst of the elements by the screen.
The same mount as before - can be vertical or horizontal.
Cheapo charger bought mainly for cable and connector.
I cut a slot in the inside wall (double wall at bottom) with my Dremel clone. I dismantled the connector and moved the PCB on to short flying leads to allow me to glue the connector in the slot I just made. The PCB sits at a right-angle in the small cavity were the hinge pin sits. Cable entry strain relief, PCB and iPhone connector are all fixed and sealed with hot-melt glue. The particular glue I have remains rubbery and allows the connector to move slightly as I fit or remove my iPhone.

Original cable grommet was used, but it was cheap and split almost immediately.
Standard car power socket spliced into aux power socket (for flexibility).
I spliced a cable mount accessory socket (which I already had in my collection of crap) on to the bike's power socket, which stays on for 5 minutes after key-off. I could have hard-wired it but this gives me more options.

The original iPhone charger I used was one of two (one in the car) cheapo chargers from Amazon. It stopped charging after a couple of rides. Testing showed the DC-DC converter inside didn't seem to always start up correctly. Through this, I found that the iPhone 3G is 12V tolerant - it is protected against having 12-odd volts connected to it's power pins!

I bought another generic phone charger (I already had the connector) from Tesco late one evening. It was rated at 5V 500mA, great, that should do it. After another couple of rides it too was dead. Further testing (which I should have done to begin with) showed that with Sat-Nav running and playing music over Bluetooth; the iPhone 3G was pulling up to 800mA. No wonder the cheap chargers aren't up to it.

I was looking through my parts looking for a LM7805 or similar, I was going to make up a small board. I then came across a small Traco DC-DC converter which I'd forgotten I had. Checking the datasheet; it has a wide input voltage range and adjustable output voltage and current up to 2A! It even has a enable line. Perfect.

I added some caps, as per the datasheet and re-used one of the cheapo housings to keep it together. Plenty of "anti-vibration" hot-melt to keep it from falling apart and the job's a good 'un.

Phone now charges from flat even if in heavy use. I'm a happy chappy.

The bike rocks, BTW. ;-)

1 comment:

  1. Ѕorrу to gatecrash уour site but might anyonе know of a solution to jaіlbreаκ iOS
    6 but?
    My web page : Repair Iphone