/* scan all key states on matrix */
uint8_t matrix_scan(void);
/* whether modified from previous scan. used after matrix_scan. */
-bool matrix_is_modified(void);
+bool matrix_is_modified(void) __attribute__ ((deprecated));
/* whether a swtich is on */
bool matrix_is_on(uint8_t row, uint8_t col);
/* matrix state on row */
matrix_row_t matrix_get_row(uint8_t row);
-/* count keys pressed */
-uint8_t matrix_key_count(void);
/* print matrix for debug */
void matrix_print(void);