https://devzone.nordicsemi.com/f/nordic-q-a/7608/i-want-to-use-the-nrf8001-with-an-attinyAn arduino board is to much for my project. I only need the interface for the NRF8001 and only 2 or three extra IO pins. Can I use the ATTINY25 and what is teh proper connection between them MISO and MOSI is not a problem, but what about REQN and RDYNen-USTelligent Community 13Mon, 15 Jun 2015 12:25:30 GMThttps://devzone.nordicsemi.com/thread/27135?ContentTypeID=1Mon, 15 Jun 2015 12:25:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e8746b98-03e5-4a30-b01e-a267e128c4b5Hung Bui<p>Hi Huibido,</p> <p>Actually you would need 6 pins to control the nRF8001: SCK, REQN,RDYN, MOSI, MISO and RESET.</p> <p>REQN pin acts like CS chip select pin, when the MCU want to enable the nRF8001.</p> <p>RDYN pin tells when the nRF8001 is ready , after the REQN is active.</p> <p>So you would need to use all the pins on the ATTINY85 and have no extra IO pins.</p> <p>I think you may have to think about a MCU with some more GPIOs.</p><div style="clear:both;"></div>