添加 back_light 函数

Author: funnygeeker

drivers/ssd1306_buf.py

@@ -101,6 +101,15 @@ def show(self):
         self.write_cmd(self.pages - 1)
         self.write_data(self.buffer)
 
+    def back_light(self, value):
+        """
+        背光调节
+
+        Args:
+            value: 背光等级 0 ~ 255
+        """
+        self.contrast(value)
+
 
 class SSD1306_I2C(SSD1306):
     def __init__(self, width, height, i2c, addr=0x3C, external_vcc=False):