https://devzone.nordicsemi.com/f/nordic-q-a/44657/host-nrf52840-returns-unexpected-nack-with-i2c-blockreadI would like to do I2C BlockRead using nRF52. devzone.nordicsemi.com/.../i2c-block-read When I looked at it, I found that it was not possible to receive variable length data. For that reason I modified nrfx_twim.c as follows. ====================en-USTelligent Community 13Mon, 11 Mar 2019 14:06:42 GMThttps://devzone.nordicsemi.com/thread/175369?ContentTypeID=1Mon, 11 Mar 2019 14:06:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:045a69a3-8aa2-4f4e-9635-e4bef40b05a1Hung Bui<p>Hei Keita,&nbsp;</p> <p></p> <p>I assume you were modifying this:&nbsp;<a href="https://github.com/zephyrproject-rtos/zephyr/blob/master/drivers/i2c/i2c_nrfx_twim.c">https://github.com/zephyrproject-rtos/zephyr/blob/master/drivers/i2c/i2c_nrfx_twim.c</a></p> <p>Not the one in our github?&nbsp;</p> <p>Could you give some explanation on the modification in&nbsp;twim_xfer() ?&nbsp;</p> <p>I assume you will have the length of the read to be in the first byte from slave ?&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/175226?ContentTypeID=1Mon, 11 Mar 2019 03:58:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3f2e4693-63d9-4f02-8641-1f28942ac549Keita.MOGAKI<p>Addendum : I am using Zephyr for OS. <br /><a href="https://github.com/zephyrproject-rtos/zephyr">https://github.com/zephyrproject-rtos/zephyr</a></p> <p><br />And the target code is below.<br /><a href="https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_twim.c">https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_twim.c</a></p><div style="clear:both;"></div>