new demo

ndir_leds.py

@@ -0,0 +1,35 @@
+import time
+
+import gex
+
+with gex.Client(gex.TrxRawUSB()) as client:
+    ser = gex.USART(client, 'ser')
+    leds = gex.SIPO(client, 'leds')
+
+    while True:
+        ser.clear_buffer()
+        ser.write([0xFF, 0x01, 0x86, 0, 0, 0, 0, 0, 0x79])
+        data = ser.receive(9, decode=None)
+
+        pp = gex.PayloadParser(data, endian="big").skip(2)
+        ppm = pp.u16()
+        
+        # The LEDs are connected to two 595's, interleaved R,G,R,G...
+        nl = (ppm-300)/1700.0
+        print("%d ppm CO₂, numleds %f" % (ppm, nl*8))
+        
+        numb = 0
+        for i in range(0,8):
+          if nl >= i*0.125:
+            if i < 3:
+              numb |= 2<<(i*2)
+            elif i < 6:
+              numb |= 3<<(i*2)
+            else:
+              numb |= 1<<(i*2)
+        
+        leds.load([(numb&0xFF00)>>8,numb&0xFF])
+        
+
+        time.sleep(1)
+