The printer power supply provided by this link is 5 9V; if you need a 12 24V power supply version, please email us after submitting the order, and we will deliver the 12 24V power supply version of the printer you need. The printer provides a physical interface of RS232/TTL+USB, the default is RS232, if you need to switch to TTL, you can contact us, we will tell you how to switch. This thermal printer prints clearly, and the paper bin can accommodate small paper rolls with a diameter of 30MM, which can be easily embedded in the detection instrument to realize the function of data printing. The printer can be connected to MCU, Android, Linux, Windows systems and other platforms, and Android provides a secondary development kit. It can easily print text, pictures, barcodes, QR codes, etc. Product packing list: Thermal printer*1; Power cord*1; Serial line*1; USB cable*1; Thermal paper roll*1; (specification 57*30) The thermal paper used by the printer is a common thermal receipt paper roll on the market, with a size of 57*30; Our thermal printer works well with a 5 9V3A power supply. Since the printer is mainly embedded in the device, it is equipped with a 2PIN power terminal cable. If an external power supply is required,You also need a 5 9V DC regulated power supply and a 2.1MM jack terminal block adapter for easier connection to the power adapter. We really like this printer because its easy to make Bold, underline , inverted text , variable line spacing, left/center/right justification, barcodes with adjustable height, and even custom QR code. To help you easily implement development, We edited a more common instruction set print example based on the instruction set, After submitting the order, we will send this print example and development materials to you by email.you can change what you need to print based on our example. Super convenient!