extern char tx_buffer[TX_BUFFER_LEN+2]; /* \n + null terminated */
#define RX_BUFFER_LEN 11
extern volatile char rx_buffer[RX_BUFFER_LEN+1]; /* null terminated */
extern char tx_buffer[TX_BUFFER_LEN+2]; /* \n + null terminated */
#define RX_BUFFER_LEN 11
extern volatile char rx_buffer[RX_BUFFER_LEN+1]; /* null terminated */