Trinket pro 3.3v issue with serial port

I am working on the TMP36 example for the trinket pro 3.3.v as shown here:

I am using the USB connection, the exact same circuit and language with the exception of changing the analog pin to A3 on the trinket pro as opposed to 0 shown in the original Arduino. I am on a a Mac OS Yosemite 10.10.2

But I get no readings on the serial port. Perhaps this is a newbie mistake, and I can't seem to find a clear answer online, but do I need an FTDI cable in order to see serial output of temperature values on the serial monitor?

Thanks guys, I really appreciate it.

Did you have an Arduino question?

Yes, I wanted to know if on Arduino IDE, in order to see the temperature values from a trinket pro 3.3v with a TMP36 sensor, I need and FTDI Cable?

I'm currently using USB with the trinket bootloader to program the chip, but i get nothing on the serial monitor (no temperature values). Is that because I need an FTDI cable?

Thank you!

From Adafruit website:

Trinket does not have a Serial port connection for debugging so the serial port monitor will not be able to send/receive data

It's our lowest-cost arduino-IDE programmable board!

The Attiny85 is a fun processor because despite being so small, it has 8K of flash, and 5 I/O pins, including analog inputs and PWM 'analog' outputs. We designed a USB bootloader so you can plug it into any computer and reprogram it over a USB port just like an Arduino. In fact we even made some simple modifications to the Arduino IDE so that it works like a mini-Arduino board.

The same non-existent serial port would connect to the FTDI cable to be converted to USB.
I think your only choice for serial out might be to get a UART with SPI interface that the trinket could control.

You could also write your code to flash an LED at different points in the program.

Or develop your code on an Uno, with serial prints as needed for debugging, then strip out/comment out the serial stuff to compile it for the Attiny85.

I think your only choice for serial out might be to get a UART with SPI interface that the trinket could control.

I'm not sure that's correct. See this answer within the Adafruit forum:

If you use an FTDI Friend or FTDI cable, you can get the Serial Monitor, just as with a regular Arduino. You can also program the Pro Trinket like a regular Arduino using FTDI:
FTDI Serial TTL-232 USB Cable : ID 70 : Adafruit Industries, Unique & fun DIY electronics and kits
FTDI Friend with Micro USB Port + extras [v3] : ID 284 : Adafruit Industries, Unique & fun DIY electronics and kits

You would use one of these instead of the Pro Trinket's USB connection