Add example using a TCA9548A I2C switch

python/samples/mux.py

@@ -0,0 +1,40 @@
+import sys
+from i2cdriver import I2CDriver, EDS
+
+# Using a TCA9548A Low-Voltage 8-Channel I2C Switch
+# Three LM75B temperature sensors are connected to 
+# channels 0,1 and 2. All are at address 0x48.
+
+class Mux:
+    def __init__(self, i2, a = 0x70):
+        self.i2 = i2
+        self.a = a
+
+    def select(self, n):
+        assert n in range(8)
+        self.i2.start(self.a, 0)
+        self.i2.write([1 << n])
+        self.i2.stop()
+
+if __name__ == '__main__':
+    i2 = I2CDriver(sys.argv[1])
+
+    mux = Mux(i2)
+    sensors = [
+        (0, EDS.Temp(i2)),
+        (1, EDS.Temp(i2)),
+        (2, EDS.Temp(i2))
+        ]
+
+    # Reset all 8 channels
+    for chan in range(8):
+        mux.select(chan)
+        i2.reset()
+
+    def read(chan, dev):
+        mux.select(chan)
+        celsius = dev.read()
+        return celsius
+
+    while 1:
+        print(" ".join(["%.1f" % read(chan, dev) for chan,dev in sensors]))