6N137 High Speed Optocoupler HC-05 Serial Module please refer to this guide:

please refer to this guide: Upgrade the Arduino Ethernet bootloader to the latest version

one hand operation

Address Decoding On-Chip

Silver Tone Product Name Tactile Switch Net Weight 10g Country of Manufacture CHINA Switch Size 12x12x9mm Material Plastic

This pin outputs a regulated 5V from the regulator on the board

6N137 High Speed Optocoupler HC-05 Serial Module please refer to this guide:The 6N137 High Speed Optocoupler is a versatile and essential component for your electronic projects. This high performance optocoupler offers a reliable and efficient way to isolate electrical signals, making it ideal for various applications. Key Features: High Speed: 10 MBit s data transfer rate for fast communication. Superior Common Mode Rejection: Minimizes noise and interference. Single Channel: Ideal for simple isolation applications.