add getting state string from bt driver

due_obd2/obd2_bt.h

@@ -21,8 +21,23 @@ Be sure to disconnect the TX and RX pins from the BT module when programming the
 #ifndef OBD2_BT_H
 #define OBD2_BT_H
 
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+// #include <Arduino.h>
+// #include "obd2_util.h"
+
+/* pins */
+#define PIN_BT_RX 19
+#define PIN_BT_TX 18
+
 #define BT_STATE_PIN 3 /* state connection pin from bluetooth module -> level high on connected */
 
+#define BT_BAUD 115200
+
+#define BT_STATE_LENGTH 13 /* length of the string identifier used for the states */
+
 enum BluetoothState
 {
     BT_INITIALISING = 0,
@@ -38,6 +53,10 @@ typedef struct obt2_bt_tag
 
 void obd2_bt_init(obd2_bt_t *bt);
 void obd2_bt_process(obd2_bt_t *bt);
+void obd2_bt_get_state(obd2_bt_t *bt, char *state);
 
+#ifdef __cplusplus
+ }
+#endif
 
 #endif // OBD2_BT_H