https://devzone.nordicsemi.com/f/nordic-q-a/2415/i2c--scl-sda-pin-changeHi In my custom project I&#39;m using pins P0.14 as SCL and P0.15 as SDA . I know the pins selection #define is in twi_master_config.h. But the question is whether I have to use twi_hw_master.c or twi_hw_master.c for this pin configuration? Do I haveen-USTelligent Community 13Tue, 12 Aug 2014 15:56:57 GMThttps://devzone.nordicsemi.com/thread/9800?ContentTypeID=1Tue, 12 Aug 2014 15:56:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d6efb60b-3335-4181-80cb-fa87ae96c4c0scytulip<p>Define it by yourself.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/9799?ContentTypeID=1Tue, 12 Aug 2014 15:43:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c21bac55-6274-4b08-b3a7-78c92bf836b3Jose Xavier<p>I couldn&#39;t find the twi_master_config.h file, where it is?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/9798?ContentTypeID=1Fri, 02 May 2014 07:10:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b296403c-eaa7-4218-9e0e-b239b4b8bd0aHPC<p>Hi,</p> <p>I found the answer myself</p> <p>According to nRf51822 Reference Manual, <em>The different signals SCL and SDA associated with the TWI master are mapped to physical pins according to the configuration specified in the PSELSCL and PSELSDA registers respectively</em> so the pins configured in the register are mapped to the TWI/I2C hardware inside the board</p> <p>Regards HPC</p><div style="clear:both;"></div>