If you've been on a long road trip with your portable USB power bank (battery pack) and discover halfway that Apple uses proprietary voltages to charge your 2nd-Gen iPod Shuffle, this instructable is for you.
The "Minty Boost" has a very good tutorial on how to wire up a USB plug to allow charging a range of different Apple devices. If you want to build something more generic to use with your power bank, such as a male-female USB cord which internally divides the right voltages into the D+ and D- USB lines, follow their tutorial or search for any Apple device battery charger instructable.
We will avoid the whole USB voltage problem by charging the shuffle straight through the audio jack, instead of through the dock (which contains circuitry of its own). This will result in a nice shuffle-only USB cable.
The wiring is based on this AllPinouts page. All we will be doing is soldering a 3.5mm 4-pole audio jack to a USB cable.
Step 1: Materials
- 2nd Generation iPod shuffle. Second and third generation shuffles have incompatible cables and docks.
- Power bank / Battery pack which has a 5V USB output. I have an Intempo 1Ah pack which has 1A and 2A ports. Note: I have not checked if the iPod charges with voltages other than 5V - it might.
- (Male) USB cable. This will be sacrificed for the greater good. I used the one that came with my power bank which only has VCC and GND wires.
- 3.5mm 4-pole audio jack. Example eBay listing here.
You will also need basic electronics equipment, namely
- A soldering iron
- Solder and optionally flux to make the job a little easier
- Wire strippers and wire
- Heatshrink or electrical tape
- A multimeter
Step 2: Soldering
- Familiarize yourself with the pin connections using a multimeter.
- Strip off some of the USB cable sheath, cut the red VCC cable so it's slightly shorter than the black GND cable, then strip the both of them. Note: only strip a short section of the black cable, this will minimize the chance of you short-circuiting it when soldering.
- Insert heatshrink and the jack sleeve into the end of the cable. Don't forget this step!
- Solder pins 1, 2 and 4 together using a short length of (preferably solid-core) wire.
- Solder GND (black) to pin 3. Be careful not to get solder between this and the adjacent connection.
- Solder VCC (red) to pin 4, i.e. the big metal bit.
- Check that your cable works by plugging it into the power bank and the iPod.
- Screw on the jack sleeve.
- Cover the exposed wires using your previously inserted heatshrink, or using electrical tape. Note: if you don't have a heat gun, just rub your soldering iron on the heatshrink to make it shrink.
Step 3: Enjoy
Now you have a handy little cable you can pack with your power bank when you go on long journeys. Never ration the tunes coming out of your iPod shuffle again!