MCU: ATmega88
 Package: 28-pin-PDIP

 1: Reset
 2: PD0 RXD0   PCINT16
 3: PD1 TXD0   PCINT17
 4: PD2 INT0   PCINT18
 5: PD3 INT1   OC2B    PCINT19
 6: PD4 T0     XCK0    PCINT20
 7: Vcc
 8: Gnd
 9: PB6 TOSC1  XTAL1   PCINT6
10: PB7 TOSC2  XTAL2   PCINT7
11: PD5 T1     OC0B    PCINT21
12: PD6 AIN0   OC0A    PCINT22
13: PD7 AIN1   PCINT23
14: PB0 ICP1   CLKO    PCINT0
15: PB1 OC1A   PCINT1
16: PB2 !SS    OC1B    PCINT2
17: PB3 MOSI   OC2A    PCINT3
18: PB4 MISO   PCINT4
19: PB5 USCK   PCINT5
20: AVCC
21: AREF
22: Gnd
23: PC0 ADC0   PCINT8
24: PC1 ADC1   PCINT9
25: PC2 ADC2   PCINT10
26: PC3 ADC3   PCINT11
27: PC4 ADC4   SDA     PCINT12
28: PC5 ADC5   SCL     PCINT13

Summary:
The high-performance Microchip picoPower 8-bit AVR RISC-based microcontroller 
8 KB ISP flash memory with read-while-write capabilities, 
512 B EEPROM, 
1 KB SRAM, 
23 general purpose I/O lines, 
32 general purpose working registers, 
2 x 8-bit, 1 x 16-bit timer/counters with compare modes, 
6-channel PWM,
1 comparators,
internal and external interrupts,
1 serial programmable USART, 
1 byte-oriented 2-wire serial interface, 
1 SPI serial port, 
6-channel 10-bit A/D converter, 
programmable watchdog timer with internal oscillator, 
5 software selectable power saving modes. 
The device operates between 1.8-5.5 volts.
