Saturday, October 11, 2014

Comparing Adafruit's Pro Trinket to Trinket and Uno


A few weeks before Getting Started with Adafruit Trinket went to press, Adafruit introduces the Pro Trinket.  It hits a sweet spot in terms of price, performance, and size between the Trinket and the Arduino Uno.  In my comparison chart in the book it was a bit late to add the Pro Trinket so I'll do it here. First, sizing them up visually:
Adafruit Trinket (top), Pro Trinket (middle) and Arduino Uno (bottom) (source: Adafruit)

The Pro Trinket is closer to Trinket's size than an Arduino Uno.   It's smaller than an Arduino Micro or Nano I believe but not by a lot.


Adafruit Trinket

Adafruit Pro Trinket
Arduino Uno

Processor
ATtiny85
Surface Mount
ATmega328P QFN package
ATmega328P
DIP Package
Digital Pins
5
12
14
Analog Pins
3 (shared)
8
6
Pulse Width Modulated Pins
3
6
6
Pin Voltage
3.3 or 5 volts
3.3 or 5 volts
5 Volts
Board Voltage
3.3 or 5 volts
3.3 or 5 volts
5 Volts (3.3 on a pin)
Regulated Current Out
150ma
150ma
800ma
Power via 3.7V LiPo
Possible
Possible
No
USB Chip Onboard
No
No (but has FTDI header)
Yes
USB Plug Type
Mini-USB
Micro-USB
USB-B
USB Programmable
Yes
Yes
Yes
Memory (RAM/EEPROM)
512 / 512 bytes
2048 / 1024 bytes
2048 / 1024 bytes
Flash Memory (free)
8K (5,130 free)
32K (28,672 bytes free)
32K (32K free)
Add-on Shields
No
No
Yes
Board Size
31mm x 15.5 x 5mm
38mm x 18mm x 2mm
75.14 x 53.51 x 15.08mm
Approximate Cost
$6.95
$9.95
$24.95


In terms of Pro Trinket compatibility with Uno, the Pro Trinket does not have digital pins 2 and 7 exposed to pins (they are permanently used for USB, although you could hack into the USB resistors with very fine wire to get them).  Sketches that use pins 2 and 7 may most likely be modifiable to use other pins.

Like some Uno clones, the Pro Trinket adds analog pins 6 and 7 which could be very useful in some applications.

What do you think?  Does the Pro Trinket fit in well in the spectrum of available microcontrollers?  Capability, price, size?