The ESP32-S is a wireless module based on ESP32, supports Wi-Fi and Bluetooth 4.2, with built-in 32Mbit Flash, in the SMD38 package. There are also on board PCB antenna and metal shield.
The MCP3421 is an I2C SOT23-6 Delta-Sigma ADC Evaluation Module Board For PIC kit Serial Analyzer PCB Module. This board works with the pickit serial analyzer.
The 2SK3515, 2SK-3515, K3515, 3515 is a 450V, 10A, 48W TO-220NIS Package MOSFET, The FUJI Electric manufacturer is a IC Chips with N CHANNEL SILICON POWER MOSFET for more details of 2SK3515 can be seen below.
The 2SC1061 is a NPN Power Transistor in To-220 package. It has a DC current gain from 35 to 320 and transition frequency of 5MHz. It is commonly used in high power amplifier application along with its complementary PNP part 2SA671.