https://devzone.nordicsemi.com/f/nordic-q-a/53159/sdk-twi-documentation-and-nrfxHello, I am developing an application on the 52840 and so far find the SDK documentation quite confusing and somewhat contradictory. I need to write a simple TWI (I2c) master driver for a peripheral. I found a simple API example in the SDK and starteden-USTelligent Community 13Tue, 15 Oct 2019 07:54:13 GMThttps://devzone.nordicsemi.com/thread/214974?ContentTypeID=1Tue, 15 Oct 2019 07:54:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ef0bafad-27fb-44dc-adf2-069063743379Amanda Hsieh<p>Hi,&nbsp;</p> <p></p> [quote user=""]If nrfx_twim is the master and nrfx_twis is the slave, what is nrfx_twi for?[/quote] <p>The nrf_drv_twi is mainly a legacy layer to map the APIs to new nrfx driver implementations. Legacy driver integrates support for<span>&nbsp;</span><a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/twi.html?cp=3_1_0_48#concept_rhy_rzp_sr">TWI</a><span>&nbsp;</span>and<span>&nbsp;</span><a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/twim.html?cp=3_1_0_32#concept_scx_f5p_xr">TWIM</a><span>&nbsp;</span>peripherals, while these are split into the separate drivers in nrfx (nrfx_twi and nrfx_twim). All implementation should work similar, but they have some changed APIs.</p> <p>The difference between TWI and TWIM peripherals is primarily the support for EasyDMA in TWIM (transfer/receive directly from/to RAM), for operations without CPU being involved.</p> <p>Please see this <a href="https://devzone.nordicsemi.com/f/nordic-q-a/49521/best-twi-i2c-driver-for-the-nrf52832/197599#197599">post</a>.</p> <p>&nbsp;</p> [quote user=""]I also see some suggestions in the forum that some drivers wont work with softdevices enabled, is this true? If so,&nbsp;which should I use when a softdevice is enabled?[/quote] <p>Please see&nbsp;<a title="nRF52 Series" href="https://infocenter.nordicsemi.com/topic/sds_s140/SDS/s1xx/sd_mgr/sd_enable_disable.html?resultof=%22%53%6f%66%74%44%65%76%69%63%65%22%20%22%73%6f%66%74%64%65%76%69%63%22%20%22%65%6e%61%62%6c%65%22%20%22%65%6e%61%62%6c%22%20%22%64%69%73%61%62%6c%65%22%20%22%64%69%73%61%62%6c%22%20">SoftDevice enable and disable</a>&nbsp;and&nbsp;<a title="Application programming interface" href="https://infocenter.nordicsemi.com/topic/sds_s140/SDS/s1xx/overview/api_overview.html?cp=3_4_3_0_3">Application programming interface</a>.</p> <p>&nbsp;</p> <p>-Amanda H.&nbsp;</p><div style="clear:both;"></div>