BSS138DW-7-F by Diodes Incorporated is a N-channel small signal FET with a min DS breakdown voltage of 50V. It is used for switching applications and operates in enhancement mode. This surface mount transistor has a max drain current of 0.2A and a max power dissipation of 0.2W.
ATMEGA328P-AU by Microchip: 8-bit RISC CPU, 20 MHz clock, 23 I/O lines. Ideal for industrial applications with SPI, TWI, USART connectivity and low power mode. Features include 2048 RAM bytes, 1024 EEPROM size, and 16384 ROM words.
N-CHANNEL; Configuration: SINGLE WITH BUILT-IN DIODE; Surface Mount: YES; Maximum Power Dissipation (Abs): .35 W; Maximum Time At Peak Reflow Temperature (s): 10; Terminal Finish: MATTE TIN;