If you are using a specific POS ecosystem (like Toast or Loyverse), use their built-in driver manager. They often have pre-verified drivers for the JK5801H.
JK5801H thermal printer — driver verified thermal printer jk5801h driver verified
/** * @brief Initializes the JK5801H printer interface. * Configures UART/GPIO pins and sends reset sequence. */ jk5801h_status_t JK5801H_Init(void); If you are using a specific POS ecosystem
Use only these verified sources:
Silence.