diff --git a/bsp.py b/bsp.py
index be11945..07ad2c5 100644
--- a/bsp.py
+++ b/bsp.py
@@ -94,6 +94,7 @@ class motor ():
 class beep():
     def __init__(self):
         self.BUZ = 4
+        GPIO.setmode(GPIO.BCM)
         GPIO.setup(self.BUZ, GPIO.OUT)
 
     def on(self):
@@ -419,4 +420,4 @@ if __name__ == '__main__':
     l = line_sensor()
     while True:
         print(l.AnalogRead())
-        time.sleep(0.2)
\ No newline at end of file
+        time.sleep(0.2)