From 1ec888759884a10ce4a5c73f4b211fcf2884d761 Mon Sep 17 00:00:00 2001
From: Adam <adamrosas1972@gmail.com>
Date: Sun, 12 Nov 2017 09:05:36 -0800
Subject: [PATCH 1/2] add power control

---
 NDIR_RasPi_Python/NDIR.py    | 14 ++++++++++++++
 NDIR_RasPi_Python/example.py | 12 ++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/NDIR_RasPi_Python/NDIR.py b/NDIR_RasPi_Python/NDIR.py
index bd9ea8a..69dfc6c 100644
--- a/NDIR_RasPi_Python/NDIR.py
+++ b/NDIR_RasPi_Python/NDIR.py
@@ -5,6 +5,8 @@ class Sensor():
     cmd_measure = [0xFF,0x01,0x9C,0x00,0x00,0x00,0x00,0x00,0x63]
     ppm         = 0
 
+    IODIR       = 0X0A << 3
+    IOSTATE     = 0X0B << 3
     IOCONTROL   = 0X0E << 3
     FCR         = 0X02 << 3
     LCR         = 0X03 << 3
@@ -96,3 +98,15 @@ def receive(self):
                 break
 
         return buf
+
+    def power_on(self):
+        state = self.read_register(self.IOSTATE)
+        state |= 1
+        self.write_register(self.IOSTATE, state)
+
+    def power_off(self):
+        self.write_register(self.IODIR,  0x03)
+        state = self.read_register(self.IOSTATE)
+        state &= ~1
+        self.write_register(self.IOSTATE, state)
+
diff --git a/NDIR_RasPi_Python/example.py b/NDIR_RasPi_Python/example.py
index 18cb72c..7236619 100644
--- a/NDIR_RasPi_Python/example.py
+++ b/NDIR_RasPi_Python/example.py
@@ -6,11 +6,19 @@
 if sensor.begin() == False:
     print("Adaptor initialization FAILED!")
     exit()
-
-while True:
+sensor.power_on()
+print("Power On")
+i = 0
+while i < 50:
+    if i == 25:
+        sensor.power_off()
+        print("Power Off")
+        sensor.ppm = -1
     if sensor.measure():
         print("CO2 Concentration: " + str(sensor.ppm) + "ppm")
     else:
         print("Sensor communication ERROR.")
 
     time.sleep(1)
+    i += 1
+

From 3b98e3e665e6258ae8b8848879e33f9a9595b3c7 Mon Sep 17 00:00:00 2001
From: Adam <adamrosas1972@gmail.com>
Date: Sun, 12 Nov 2017 10:12:41 -0800
Subject: [PATCH 2/2] improve sensor communication

---
 NDIR_RasPi_Python/NDIR.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/NDIR_RasPi_Python/NDIR.py b/NDIR_RasPi_Python/NDIR.py
index 69dfc6c..e837f14 100644
--- a/NDIR_RasPi_Python/NDIR.py
+++ b/NDIR_RasPi_Python/NDIR.py
@@ -48,7 +48,7 @@ def measure(self):
         try:
             self.write_register(self.FCR, 0x07)
             self.send(self.cmd_measure)
-            time.sleep(0.01)
+            time.sleep(0.02)
             self.parse(self.receive())
             return True
         except IOError: