Thu
Jun 9

DIY USB-Serial Cable

Ever since I saw Minty Boost I knew that I wanted to make a small electronic device and put it in a funky case. Well, tonight I can finally sleep the untroubled sleep of one whose desires are fulfilled. Behold, the Tic Tac USB-Serial cable, Cherry Passion edition!

  1. Eat all the Tic Tacs.
  2. Assemble a USB Serial cable.
  3. Place the cable circuit board in the Tic Tac box. Add hot glue and masking tape for authenticity.

This uses the famous FTDI FT232RL chip to present a USB serial interface to a computer at one end, while presenting TTL-level serial lines on the other. I made mine mimic FTDI's standard cable, with a 6-socket header at the TTL end. (It contains transmit, receive, power, and flow control lines.)

The chip itself is only available in various surface-mount formats, so I prudently circumvented a fine-wire-soldering nightmare (and ensuing insanity) by purchasing a a 28-pin SSOP breakout.

Soldering surface mount components is easier than people claim as long as you douse the area in flux first, a technique I learnt from electronics wizard Dave Snowdon.

Speaking of dousing things in other things, I hope you are appreciating the hot glue job I did here.

Here is the device programming a Nanode.

Click images for larger versions.