MEAM.Design - ItsyBitsy - Board Pinout & Functionality

Pinout of Adafruit ItsyBitsy32u4 5V version

Left Side

RST Reset Active low reset (> 400ns pulse to reset)
5V 5V Power from battery regulator 5V or USB through diode ~4.8V
AREF AREF Analog Reference Voltage (input) for the A/D converter
GND GND board ground
F7 F7 GPIO port F, bit 7
ADC7 analog-to-digital converter, channel 7
F6 F6 GPIO port F, bit 6
ADC6 analog-to-digital converter, channel 6
F5 F5 GPIO port F, bit 5
ADC5 analog-to-digital converter, channel 5
F4 F4 GPIO port F, bit 4
ADC4 analog-to-digital converter, channel 4
F1 F1 GPIO port F, bit 1
ADC1 analog-to-digital converter, channel 1
F0 F0 GPIO port F, bit 0
ADC0 analog-to-digital converter, channel 0
B1 B1 GPIO port B, bit 1
PCINT1 pin-change interrupt, channel 1
SCLK SPI bus serial clock
B2 B2 GPIO port B, bit 2
PCINT2 pin-change interrupt, channel 2
MOSI SPI master-out/slave-in
B3 B3 GPIO port B, bit 3
PCINT3 pin-change interrupt, channel 3
MISO SPI master-in/slave-out
3.3V 3.3V Weak internal 3.3V supply (up to ~55mA with 5V USB)

Right Side

VBAT VBAT +Input from battery (up to 16V)
GND GND board ground
VBUS VBUS 5V Power from USB (no protection)
C7 C7 GPIO port C, bit 7; connected to RED led (high = on)
ICP3 Input capture, channel 3
OC4A output compare 4A
D6 D6 GPIO port D, bit 6;
T1 Timer 1 external clock input
ADC9 analog-to-digital converter, channel 9
/OC4D inverted output compare 4D
B7 B7 GPIO port B, bit 7
PCINT7 pin-change interrupt, channel 7
OC0A output compare 0A
OC1C output compare 1C
/RTS UART flow control
B6 B6 GPIO part B, bit 6
PCINT6 pin-change interrupt, channel 6
ADC13 analog-to-digital converter, channel 13
OC1B output compare 1B
OC4B output compare 4B
B5 B5 GPIO port B, bit 5
PCINT5 pin-change interrupt, channel 5
ADC12 analog-to-digital converter, channel 12
OC1A output compare 1A
/OC4B inverted output compare 4B
E6 E6 GPIO port E, bit 6;
INT6 external interrupt, channel 6
AIN0 analog comparator positive input
C6 C6 GPIO port C, bit 6
OC3A output compare 3A
/OC4A inverted output compare 4A
D0 D0 GPIO port D, bit 0 (pulled up by a 2.2k resistor)
OC0B output compare 0B
SCL I2C (TWI) clock
INT0 External Interrupt, channel 0
D1 D1 GPIO port D, bit 1 (pulled up by a 2.2k resistor)
SDA I2C (TWI) data
INT1 External Interrupt, channel 1
D3 D3 GPIO port D, bit 3
TXD1 USART transmit
INT3 External Interrupt, channel 3
D2 D2 GPIO port D, bit 2
RXD1 USART receive
INT2 External Interrupt, channel 2

Bottom Row

D4 D4 GPIO port D, bit 4
ICP1 Input capture, channel 1
ADC8 analog-to-digital converter, channel 8
D7 D7 GPIO port D, bit 7
T0 Timer 0 external clock input
ADC10 analog-to-digital converter, channel 10
OC4D output compare 4D
B4 B4 GPIO port B, bit 4
PCINT4 pin-change interrupt, channel 4
ADC11 analog-to-digital converter, channel 11
GND GND board ground
EN EN Battery voltage regulator enable. Drive low to disconnect battery.