diff --git a/Firmware/config.h b/Firmware/config.h
index c64bd441..922a5398 100644
--- a/Firmware/config.h
+++ b/Firmware/config.h
@@ -31,8 +31,11 @@
 
 //PAT9125 configuration
 //#define PAT9125_SWSPI // software SPI mode (incomplete)
-//#define PAT9125_SWI2C // software I2C mode
+#ifdef SWI2C_SCL
+#define PAT9125_SWI2C   // software I2C mode
+#else
 #define PAT9125_I2C     // hardware I2C mode
+#endif
 
 #define PAT9125_I2C_ADDR  0x75  //ID=LO
 //#define PAT9125_I2C_ADDR  0x79  //ID=HI
diff --git a/Firmware/pins_Einsy_1_0.h b/Firmware/pins_Einsy_1_0.h
index 14b56233..21578ebd 100755
--- a/Firmware/pins_Einsy_1_0.h
+++ b/Firmware/pins_Einsy_1_0.h
@@ -18,12 +18,6 @@
 #define W25X20CL                 // external 256kB flash
 #define BOOTAPP                  // bootloader support
 
-
-#define SWI2C_SDA      20 //SDA on P3
-#define SWI2C_SCL      21 //SCL on P3
-
-
-
 #define X_TMC2130_CS           41
 #define X_TMC2130_DIAG         64 // !!! changed from 40 (EINY03)
 #define X_STEP_PIN             37
diff --git a/Firmware/pins_Rambo_1_3.h b/Firmware/pins_Rambo_1_3.h
index 538fb4f3..522ad28f 100644
--- a/Firmware/pins_Rambo_1_3.h
+++ b/Firmware/pins_Rambo_1_3.h
@@ -11,9 +11,6 @@
 
 #define PINDA_THERMISTOR
 
-#define SWI2C_SDA      20 //SDA on P3
-#define SWI2C_SCL      21 //SCL on P3
-
 #ifdef MICROMETER_LOGGING
 #define D_DATACLOCK		24	//Y_MAX (green)
 #define D_DATA			30	//X_MAX (blue)
diff --git a/Firmware/swi2c.c b/Firmware/swi2c.c
index 49fbc5ef..62a28e1a 100644
--- a/Firmware/swi2c.c
+++ b/Firmware/swi2c.c
@@ -7,6 +7,7 @@
 #include "pins.h"
 #include "io_atmega2560.h"
 
+#ifdef SWI2C_SCL
 
 #define SWI2C_RMSK   0x01 //read mask (bit0 = 1)
 #define SWI2C_WMSK   0x00 //write mask (bit0 = 0)
@@ -187,3 +188,5 @@ uint8_t swi2c_writeByte_A16(uint8_t dev_addr, unsigned short addr, uint8_t* pbyt
 }
 
 #endif //SWI2C_A16
+
+#endif //SWI2C_SCL