@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+_PIN_FD_PATH = '/proc/adc%s'
+
+
+def analog_read(channel):
+    """Return the integer value of an adc pin.
+
+    adc0 and adc1 have 6 bit resolution.
+    adc2 through adc5 have 12 bit resolution.
+
+    """
+
+
+    with open(_PIN_FD_PATH % channel, 'r') as f:
+        return int(f.read(32).split(':')[1].strip())
@@ -0,0 +1,23 @@
+import time
+from adc import analog_read
+
+def delay(ms):
+    time.sleep(1.0*ms/1000)
+
+def setup():
+		print "read channel ADC2 value ,the V-REF = 3.3V"
+		delay(3000)
+
+def loop():
+    while(1):
+        value = analog_read(2)
+	voltage = (value * 3.3)/4096
+        print ("value =  %4d"%value)
+	print ("voltage =  %4.3f  V" %voltage)
+	delay(100)
+
+def main():
+    setup()
+    loop()
+
+main()