Each Model of HC Bluetooth is very popular for using with any Microcontroller such as Arduino or STM. Bluetooth is easy for you to control wirelessly any device in short rang via your Phone or Computer. Bluetooth model of HC have communication protocol UART.
The DRV8825 is a Motor Driver with two H-bridge drivers and a microstepping indexer. The driver has a maximum output capacity of 45 V and ± 2.5 A. It can operate bipolar stepper motors in full, 1/2, 1/4, 1/8, 1/16 and 1/32-step modes. This driver module is generally used in Robotics, ATMs and Gaming Machines.
The module (MicroSD Card Adapter) is a Micro SD card reader module, through the file system and the SPI interface driver, SCM system to complete the file to read and write MicroSD card. Arduino users can directly use the Arduino IDE comes with an SD card to complete the library card initialization and read