I'm the author of the Arduino CC3000 library (https://github.com/cmagagna/ArduinoCC3000). I need more boards for development but all of T.I.'s are either out of stock or weirdly overpriced, and I've seen several designs for breakout boards but none actually built yet... so I decided to roll my own:
If you could look over the board and let me know what you think I'd appreciate it.
I based my board on Matt Bigarani's design (http://www.centerblack.com) but I changed the RX & TX lines from pins to just solder pads (not really needed since they're only used for testing), added cuttable traces for the I2C lines (also only used for testing), combined the VBAT_IN and VIO_HOST lines (T.I. does this on their own board) and changed the pin layout from 1x10 to 2x4 so it will plug into a standard breadboard.
I've tried to follow all the design points outlined in the CC300 spec sheet (http://www.ti.com/lit/ds/swrs126/swrs126.pdf), evaluation module (http://www.ti.com/lit/ug/swru326/swru326.pdf), and Boosterpack board (http://www.ti.com/lit/ug/swru331/swru331.pdf):
- the power supply trace is 40 mil
- the test point traces are 18 mil
- the antenna trace is 14.3 mil with a 10 mil separation
- the antenna area is 10.4mmx8.1mm
- the distance from the antenna trace to the edge of the PCB is 1.1mm
- the antenna trace is rounded
- There's via stitching between the ground and the antenna trace
- There's a lot of vias between the 2 ground layers
There's two points I'm not sure about:
- Distance between layers is supposed to be 52.2 mil. A standard 1/16" board (1.6mm) is 62.5 mils and a 1.2mm board is 47 mils...how would you get a 52.2 mil spacing?
- "RF traces must have 50 Ohm impedance (micros trip transmission line)". What does this mean?
Thanks in advance for any advice.
[edit - fixed wrong URL]