diff --git a/src/app/i2cbench/main.cc b/src/app/i2cbench/main.cc
index c9c2b70e1c9858881d0eac17c906ef984c3f2b25..53048164331984a08eb50feaee313a828aed1ed9 100644
--- a/src/app/i2cbench/main.cc
+++ b/src/app/i2cbench/main.cc
@@ -25,8 +25,9 @@
 void loop(void)
 {
 #ifdef DRIVER_LM75
-	kout.printf_float(lm75.getTemp());
-	kout << endl;
+	//kout.printf_float(lm75.getTemp());
+	//kout << endl;
+	lm75.setOS(64);
 #endif
 #ifdef DRIVER_AM2320
 	am2320.read();
diff --git a/src/arch/arduino-nano/Makefile.inc b/src/arch/arduino-nano/Makefile.inc
index d481fa2153de33b2915c21346134644d25557131..18a65633e00a9bb58d57fe9a8ec3fd803366b185 100644
--- a/src/arch/arduino-nano/Makefile.inc
+++ b/src/arch/arduino-nano/Makefile.inc
@@ -32,6 +32,10 @@ ifneq ($(findstring stdin,${arch_drivers}), )
 	TARGETS += src/arch/arduino-nano/driver/stdin.cc
 endif
 
+ifneq (${i2c_freq}, )
+	COMMON_FLAGS += -DF_I2C=${i2c_freq}
+endif
+
 OBJECTS = ${TARGETS:.cc=.o}
 
 .cc.o:
diff --git a/src/arch/arduino-nano/driver/i2c.cc b/src/arch/arduino-nano/driver/i2c.cc
index cfbea591131680c4072ab3ce0b5c80fa8d6c19fb..0a2f595290903ba0434b61b0a64dd69dd420af81 100644
--- a/src/arch/arduino-nano/driver/i2c.cc
+++ b/src/arch/arduino-nano/driver/i2c.cc
@@ -3,6 +3,10 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 
+#ifndef F_I2C
+#define F_I2C 100000UL
+#endif
+
 inline void await_twint(unsigned char twcr_values)
 {
 	TWCR = twcr_values | _BV(TWINT) | _BV(TWIE);
@@ -99,7 +103,7 @@ static signed char i2c_receive(uint8_t len, uint8_t *data)
 signed char I2C::setup()
 {
 	TWSR = 0;
-	TWBR = ((F_CPU / 100000UL) - 16) / 2;
+	TWBR = ((F_CPU / F_I2C) - 16) / 2;
 
 	return 0;
 }