The Micro SD TF Card Module is SPI interface via file system driver, microcontroller system to complete the MicroSD card reading and writing functions.
This is a 3.3V to 12V Mini DC-DC Boost Step Up Converter Board Module 5V/ 8V/ 9V 12V Output is a DC-DC Boost step-up converter module that is used to step up the voltage.
This is a thermal printer like you would find on a cash register or adding machine. It will print simple strings passed to it via TTL serial, bitmap images (poorly) and it can generate several different formats of barcodes.
The MOSFET Trigger Switch Driver Module is of high power MOSFET trigger switch driver and control with field-effect tube to adjust the electronic switch.