https://devzone.nordicsemi.com/f/nordic-q-a/19038/reducing-twi-active-currentHello, I am currently working on an ultra-low power project that requires reading an I2C accelerometer multiple times per second. After analyzing the current consumption in the design, it is clear that the TWI peripheral uses quite a bit of power.en-USTelligent Community 13Tue, 24 Jan 2017 20:22:04 GMThttps://devzone.nordicsemi.com/thread/73604?ContentTypeID=1Tue, 24 Jan 2017 20:22:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ee1876a7-2f72-4025-90ff-dc0483865c6bRoger Clark<p>You should consider changing your custom board to use SPI if your accelerometer supports that interface, because SPI can transfer data much faster than TWI, and the time you need to run the processor can be many time lower.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/73603?ContentTypeID=1Tue, 24 Jan 2017 15:49:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3f62b20b-e93c-4eef-8421-8bb7d78447c6Stian R&#248;ed Hafskjold<p>As you say, the extra current is probably coming from the CPU. The nRF51 does not have DMA, so the CPU needs to be involved after each byte transfer to read/write the bytes into the RXD/TXD register in the TWI peripheral.</p><div style="clear:both;"></div>