Datasheet

Note that the I2C pins do not have pullup resistors already! You must add them if you want to communicate with an

I2C device

GPIO & Analog Pins

There are tons of GPIO and analog inputs available to you for connecting LEDs, buttons, switches, sensors, etc. Here's

the remaining pins available.

Bottom row:

A0 - this is an analog input A0 and also an analog output DAC2. It can also be used as a GPIO #26. It uses ADC

A1 - this is an analog input A1 and also an analog output DAC1. It can also be used as a GPIO #25. It uses ADC #2

A2 - this is an analog input A2 and also GPI #34. Note it is

not

an output-capable pin! It uses ADC #1