Netduino is equipped with a varied set of Input and Output (I/O) ports that can be accessed from your application to read sensors, listen to button presses, light LEDs, drive motors, communicate with other systems, and lots more.
Netduino IO ports are divided into two categories; Digital and Analog.
General Purpose Input/Output (GPIO) Ports
The Digital ports can be set to be high (powered at 3.3v), or low (grounded at 0v) which correspond to digital 1 and 0, respectively. Additionally, they have built-in support for a host of different types of common digital communication protocols:
- I2C (Inter Integrated Circuit)
- PWM (Pulse Width Modulation)
- SPI (Serial Peripheral Interface)
- UART (Serial)
I2C is normally used to connect low speed devices over short distances. Compare this to the main characteristics of SPI and Serial communications:
|SPI||Minimum of two wires, often more
Used for communication between boards
Can be used to communicate with on board devices
Analog ports can operate at a range of voltages between
3.3V, which is especially useful when reading analog sensors that supply their data as a voltage reading, rather than a digital signal.
Current Tolerance and Output
- Maximum GPIO Current - The maximum current output is
- Maximum MCU Output Current - The total maximum current output for all pins is
- Digital I/O -
3.3Vnominal, but tolerant up to
- IOREF -
3.3V(for shield compatibility).
Onboard Button & LED
In addition to the Analog and Digital Headers, the Netduino has an LED and a Button built into it that you can access from code. See the Onboard Button and LED guide for more information.
Netduino 2 and 3 can access up to 2GB of storage on a Micro SD Card. Some models have an SD card slot on the board, but models that don’t have one built in can use an SD Card Shield. See the SD Card File IO guide for ore information.