Fixed sign error on uart_buff

quad/sw/modular_quad_pid/src/uart_buff.c

@@ -351,7 +351,7 @@ size_t uart_buff_calc_index(int given_index) {
 /**
  * Return a pointer to the start of the packet.
  */
-char * uart_buff_get_raw(size_t *packet_size) {
+u8 * uart_buff_get_raw(size_t *packet_size) {
   // Copy packet into temp buffer
   *packet_size = uart_buff_packet_size();
   int i;

quad/sw/modular_quad_pid/src/uart_buff.h

@@ -21,7 +21,7 @@ size_t uart_buff_size();
 size_t uart_buff_data_length();
 int uart_buff_empty();
 int uart_buff_full();
-char * uart_buff_get_raw(size_t *);
+u8 * uart_buff_get_raw(size_t *);
 void uart_buff_print();
 u32 uart_buff_packets_processed();
 void uart_buff_reset();