Iteaduino Leonardo
iteadstudio.com
2012-07-17
5
Tech Support: [email protected]
Memory
The ATmega32u4 has 32 KB (with 4 KB used for the bootloader). It also has 2.5 KB
of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM
library).
Input and Output
Each of the 20 digital i/o pins on the Uno can be used as an input or output,
using pinMode(), digitalWrite(), anddigitalRead() functions. They operate at 5 volts.
Each pin can provide or receive a maximum of 40 mA and has an internal pull-up
resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have
specialized functions:
Serial: 0 (RX) and 1 (TX).
Used to receive (RX) and transmit (TX) TTL serial data
using the ATmega32U4hardware serial capability. Note that on the Leonardo,
the
Serial
class refers to USB (CDC) communication; for TTL serial on pins 0 and 1,
use the
Serial1
class.
TWI: 2 (SDA) and 3 (SCL).
Support TWI communication using the Wire library.
External Interrupts: 2 and 3.
These pins can be configured to trigger an interrupt
on a low value, a rising or falling edge, or a change in value. See
the attachInterrupt() function for details.
PWM: 3, 5, 6, 9, 10, 11, and 13.
Provide 8-bit PWM output with
the analogWrite() function.
SPI: on the ICSP header.
These pins support SPI communication using the SPI
library. Note that the SPI pins are not connected to any of the digital I/O pins as they
are on the Uno, They are only available on the ICSP connector. This means that if
you have a shield that uses SPI, but does NOT have a 6-pin ICSP connector that
connects to the Leonardo's 6-pin ICSP header, the shield will not work.
LED: 13.
There is a built-in LED connected to digital pin 13. When the pin is HIGH
value, the LED is on, when the pin is LOW, it's off.
Analog Inputs: A0-A5, A6 - A11 (on digital pins 4, 6, 8, 9, 10, and 12).
The
Leonardo has 12 analog inputs, labeled A0 through A11, all of which can also be
used as digital i/o. Pins A0-A5 appear in the same locations as on the Uno; inputs
A6-A11 are on digital i/o pins 4, 6, 8, 9, 10, and 12 respectively. Each analog input
provides 10 bits of resolution (i.e. 1024 different values). By default the analog
inputs measure from ground to 5 volts, though is it possible to change the upper end
of their range using the AREF pin and the analogReference() function.
There are a couple of other pins on the board:
