https://devzone.nordicsemi.com/f/nordic-q-a/22007/i2c-how-can-i-read-and-write-data-from-my-vl6180x-sensor-through-nrf51-kit-under-nrf_drv_twi_tx-and-rx-functionsThe default I2C address of my sensor is 0x29 (7-bit). If the least significant bit is low (0x52) the message is a master write to the slave. If the lsb is set (0x53) then the message is a master read from the slave. The part of my code is below. I needen-USTelligent Community 13Mon, 15 May 2017 09:40:31 GMThttps://devzone.nordicsemi.com/thread/86363?ContentTypeID=1Mon, 15 May 2017 09:40:31 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d381a02d-5bfb-4879-b6e6-416416f1d26dbjorn-spockeli<p>Just define it</p> <pre><code>#define I2C_DEV_ADDR 0x29 </code></pre> <p>and then pass it as an argument in the function calls, e.g.</p> <pre><code>err_code = nrf_drv_twi_tx(&amp;I2C_instance I2C_DEV_ADDR,&amp;reg, sizeof(reg), true); </code></pre><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/86362?ContentTypeID=1Mon, 15 May 2017 09:16:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cdcff356-afda-4b03-9b96-c5a3add9e201mert<p>how can I write that address in my code to be able to read/write data from my sensor?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/86361?ContentTypeID=1Mon, 15 May 2017 08:51:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:60bd08a9-c9e2-45f5-b65c-6974d00d184abjorn-spockeli<p>The nrf_twi_drv_rx/tx function calls will set the Read/Write bit automatically, i.e. you should only have to provide the I2C address of your device, which in your case is 0x29.</p><div style="clear:both;"></div>