1 files changed, 17 insertions, 0 deletions
diff --git a/stm/usart.h b/stm/usart.h
index 15ed419fe7..541cb757c8 100644
--- a/stm/usart.h
+++ b/stm/usart.h
@@ -1 +1,18 @@
+typedef enum {
+    PYB_USART_NONE = 0,
+    PYB_USART_1 = 1,
+    PYB_USART_2 = 2,
+    PYB_USART_3 = 3,
+    PYB_USART_6 = 4,
+    PYB_USART_MAX = 4,
+} pyb_usart_t;
+
+extern pyb_usart_t pyb_usart_global_debug;
+
+void usart_init(pyb_usart_t usart_id, uint32_t baudrate);
+bool usart_rx_any(pyb_usart_t usart_id);
+int usart_rx_char(pyb_usart_t usart_id);
+void usart_tx_str(pyb_usart_t usart_id, const char *str);
+void usart_tx_strn_cooked(pyb_usart_t usart_id, const char *str, int len);
+
 mp_obj_t pyb_Usart(mp_obj_t usart_id, mp_obj_t baudrate);