ATmega32U4 8-Bit Microcontroller with USB (TQFP-44)
16MHz, 32kB Flash, 2.5kB SRAM, 1kB EEPROM, USB 2.0, TQFP-44
Aliase:ATmega32U4, Arduino Leonardo MCU, Pro Micro MCU
TQFP-44 Top View
44 Pins
Pin-Tabelle44
| Pin | Signal / Name | Typ | Alternative Funktionen |
|---|---|---|---|
| 1 | PE6 | Digital | INT6 — External Interrupt 6 (edge or level triggered)AIN0 — Analog Comparator Positive Input |
| 2 | UVCC | Power | USB Voltage Regulator Input (connect to VCC or dedicated USB supply; place 100nF bypass cap to UGND) |
| 3 | D- | Digital | USB Data Negative (D-) — connect directly to USB connector via 22Ω series resistor |
| 4 | D+ | Digital | USB Data Positive (D+) — connect directly to USB connector via 22Ω series resistor |
| 5 | UGND | Ground | USB Ground — connect to system GND; keep trace short to USB connector |
| 6 | UCAP | Power | USB PLL Filter Capacitor — connect 1µF capacitor to GND; used internally by USB regulator |
| 7 | VBUS | Digital | USB VBUS Sense — connect to USB +5V through 22kΩ; used to detect USB cable insertion |
| 8 | PB0 | Digital | SS — SPI Slave Select (Active Low)PCINT0 — Pin Change Interrupt 0 |
| 9 | PB1 | Digital | SCK — SPI ClockPCINT1 — Pin Change Interrupt 1 |
| 10 | PB2 | Digital | PDI — SPI Programming Data In (also MOSI in SPI master mode)MOSI — SPI Master Out / Slave InPCINT2 — Pin Change Interrupt 2 |
| 11 | PB3 | Digital | PDO — SPI Programming Data Out (also MISO in SPI master mode)MISO — SPI Master In / Slave OutPCINT3 — Pin Change Interrupt 3 |
| 12 | PB7 | Digital | OC0A — Timer/Counter0 Compare Match A Output (PWM)OC1C — Timer/Counter1 Compare Match C Output (PWM)RTS — UART Hardware Flow Control (RTS signal)PCINT7 — Pin Change Interrupt 7 |
| 13 | RESET | Digital | Master Reset Input (Active Low; connect 10kΩ pull-up to VCC; 100nF filter cap optional) |
| 14 | VCC | Power | Positive Power Supply (2.7V – 5.5V) |
| 15 | GND | Ground | System Ground (0V) |
| 16 | XTAL2 | Digital | Crystal Oscillator Output — connect to crystal (16MHz typical for USB operation) |
| 17 | XTAL1 | Digital | Crystal Oscillator Input — connect to crystal or external clock source |
| 18 | PD0 | Digital | OC0B — Timer/Counter0 Compare Match B Output (PWM)SCL — I2C Clock (TWI interface)INT0 — External Interrupt 0 |
| 19 | PD1 | Digital | SDA — I2C Data (TWI interface)INT1 — External Interrupt 1 |
| 20 | PD2 | Digital | RXD1 — USART1 Receive DataINT2 — External Interrupt 2 |
| 21 | PD3 | Digital | TXD1 — USART1 Transmit DataINT3 — External Interrupt 3 |
| 22 | PD5 | Digital | XCK1 — USART1 External ClockCTS — UART Hardware Flow Control (Clear to Send) |
| 23 | GND | Ground | System Ground (0V) |
| 24 | AVCC | Power | Analog Supply Voltage — connect to VCC via 100nF bypass cap; used by ADC and analog comparator |
| 25 | PD4 | Digital | ICP1 — Timer/Counter1 Input Capture PinADC8 — ADC Channel 8 Input |
| 26 | PD6 | Digital | T1 — Timer/Counter1 External Clock Input~OC4D — Timer4 Compare Match D Inverted Output (PWM)ADC9 — ADC Channel 9 Input |
| 27 | PD7 | Digital | T0 — Timer/Counter0 External Clock InputOC4D — Timer4 Compare Match D Output (PWM)ADC10 — ADC Channel 10 Input |
| 28 | PB4 | Digital | ADC11 — ADC Channel 11 InputPCINT4 — Pin Change Interrupt 4 |
| 29 | PB5 | Digital | OC1A — Timer/Counter1 Compare Match A Output (PWM)~OC4B — Timer4 Compare Match B Inverted Output (PWM)ADC12 — ADC Channel 12 InputPCINT5 — Pin Change Interrupt 5 |
| 30 | PB6 | Digital | OC1B — Timer/Counter1 Compare Match B Output (PWM)OC4B — Timer4 Compare Match B Output (PWM)ADC13 — ADC Channel 13 InputPCINT6 — Pin Change Interrupt 6 |
| 31 | PC6 | Digital | OC3A — Timer/Counter3 Compare Match A Output (PWM)~OC4A — Timer4 Compare Match A Inverted Output (PWM) |
| 32 | PC7 | Digital | ICP3 — Timer/Counter3 Input Capture PinCLK0 — System Clock Output (divided)OC4A — Timer4 Compare Match A Output (PWM) |
| 33 | HWB/PE2 | Digital | HWB — Hardware Boot Enable: pull LOW during reset to force DFU bootloader entry |
| 34 | VCC | Power | Positive Power Supply (2.7V – 5.5V) |
| 35 | GND | Ground | System Ground (0V) |
| 36 | PF7 | Digital | ADC7 — ADC Channel 7 InputTDI — JTAG Test Data In |
| 37 | PF6 | Digital | ADC6 — ADC Channel 6 InputTDO — JTAG Test Data Out |
| 38 | PF5 | Digital | ADC5 — ADC Channel 5 InputTMS — JTAG Test Mode Select |
| 39 | PF4 | Digital | ADC4 — ADC Channel 4 InputTCK — JTAG Test Clock |
| 40 | PF1 | Digital | ADC1 — ADC Channel 1 Input |
| 41 | PF0 | Digital | ADC0 — ADC Channel 0 Input |
| 42 | AREF | Analog | Analog Reference Voltage — connect 100nF bypass cap to GND; select via ADMUX register |
| 43 | GND | Ground | System Ground (0V) |
| 44 | AVCC | Power | Analog Supply Voltage — connect to VCC via 100nF bypass cap; required even when ADC is not used |