Stem Shield for your Arduino, the Velleman.

The ESP32-CAM is a WIFI + Bluetooth Development Card based on the ESP32 Chip, with the additional possibility of using a camera. It is ideal for a variety of loT applications.

A ESP32 NodeMcu WiFi CP2102 Module with Built-in Antenna, MicroUSB Connector, Bluetooth BLE 4.2, Analog Digital Converter, GPIO with PWM Functions, 12C, SPI, Etc and Supports Remote Firmware Upgrade.

This RS232 shield is designed for the Arduino controller and can easily convert UART to RS232 interface.

This 4-digit 7-segment shield has 5 buttons that can be used as menu selection buttons or control buttons, using I2C to conduct the digital call.

The Vma210 Expansion Board is designed to allow easy access to the interface pins of an Arduino Nano. Each DIO pin or analog pin on the Nano is brought to an appropriate header.