Mini-Project: 30 Pin/USB-C adapter

One afternoon a few weeks ago, I realized that I needed a way to charge my iPod nano during an upcoming vacation. So, instead of studying for my imminent exam that afternoon :D, I decided to speed build a 30 Pin / USB-C charging adapter using components I had on hand.

The first gen iPod nano which I decided to bring on the trip uses the infamous proprietary 30 Pin connector. Pin 23 connects to the +5V rail, whereas pins 1 and 29 (among others) are tied to ground.

In order to make the adapter work with all types of chargers (including PD), it needs to pull the USB CC lines to ground via a 5.1K resistor, which indicates to PD chargers that the downstream device is 5V only.

So the BOM the adapter is as such: 30 Pin connectors + Breakout PCB which I had on hand from previous experimentation, 0603 5.1K resistors I have on hand for the JPL.mp3 project, and an SMT USB-C connector also on hand for the mp3 player.

I started by assembling the connector and soldering on the PCB. I prepared a few bits of enameled copper wire by heating my iron to 450C and then tinning the ends of each segment. Next, I soldered two of the tiny resistors to pins 1 and 29 on the exposed side of the breakout. I added wires on either side of both resistors, and two wires on 23 for the +5V. In order to make sure everything fit, I widened the hole at the bottom of the connector's casing, subsequently supergluing the bare connector in case. The, consulting the USB-C connector's pinout, I (tediously) soldered each of the enamel wires to the corresponding pin on the USB-C connector. After assembling everything, twisting up all the excess wire, and testing the device, I potted everything in a copious amount of hot glue and closed it up!