1 files changed, 40 insertions, 0 deletions
diff --git a/src/driver/max44009.cc b/src/driver/max44009.cc
new file mode 100644
index 0000000..3981e79
--- /dev/null
+++ b/src/driver/max44009.cc
@@ -0,0 +1,40 @@
+#include "driver/max44009.h"
+#if defined(MULTIPASS_ARCH_HAS_I2C) && !defined(DRIVER_SOFTI2C)
+#include "driver/i2c.h"
+#else
+#include "driver/soft_i2c.h"
+#endif
+
+float MAX44009::getLux()
+{
+	unsigned char luxHigh;
+	unsigned char luxLow;
+	unsigned int mantissa, exponent;
+
+	txbuf[0] = 0x03;
+	txbuf[1] = 0x04;
+
+	i2c.xmit(address, 2, txbuf, 2, rxbuf);
+
+	luxHigh = rxbuf[0];
+	luxLow = rxbuf[1];
+
+	/*
+	* The lowest 4 bit of luxLow are the lowest 4 bit of the mantissa.
+	* The lowest 4 bit of luxHigh are the highest 4 bit of the mantissa.
+	*/
+	mantissa = (luxLow & 0x0F) + ((luxHigh & 0x0F) << 4);
+
+	/*
+	* The highest 4 bit of luxHigh are the 4 bit exponent
+	*/
+	exponent = (luxHigh & 0xF0) >> 4;
+
+	/*
+	* Cast base and mantissa to float to avoid calculation errors
+	* because of 16bit integer overflows.
+	*/
+	return (float)(1 << exponent) * (float)mantissa * 0.045;
+}
+
+MAX44009 max44009(0x4a);