1 files changed, 8 insertions, 0 deletions
diff --git a/xbee.h b/xbee.h
index 53f9288..f868972 100644
--- a/xbee.h
+++ b/xbee.h
@@ -1,7 +1,13 @@
 #ifndef XBEE_H
 #define XBEE_H
 
+#include "mutex.h"
+
+Mutex xbm;
+
 void xbee_send(uint16_t type, int len, const uint8_t* buf) {
+	xbm.lock();
+	
 	// Start and length.
 	usart_send(0x7e);
 	usart_send(((len + 16) >> 8) & 0xff);
@@ -40,6 +46,8 @@ void xbee_send(uint16_t type, int len, const uint8_t* buf) {
 	}
 	
 	usart_send(chsum);
+	
+	xbm.unlock();
 }
 
 #endif