diff --git a/class1/README.md b/class1/README.md
index f00f56a9da6a4c932a5b0be592f238d3f82e7647..51eb19c740c70f8595eb8afb082ce422a5bb16af 100644
--- a/class1/README.md
+++ b/class1/README.md
@@ -342,6 +342,8 @@ sudo apt install terminator tree vim build-essential -y
          GPIO.cleanup()
      ```
 
+![raspberry-pi pins](images/pins.png)
+
      - 例子2
     
         ```python
@@ -349,14 +351,12 @@ sudo apt install terminator tree vim build-essential -y
         from gpiozero import PWMLED
         from time import sleep
         
-        led = PWMLED(17)
+        led = PWMLED(5)
         
         i = 0
         while i<10:
             led.value = 0
             sleep(1)
-            led.value = 0.5
-            sleep(1)
             led.value = 1
             sleep(1)
             i = i + 1