@Yveaux Thanks so much for confirmation, Seems a large community of people faced the issue here back in 2014 link text , and the recomendation comes from this past experience. My undertanding is nobody re-challenged the recomendation and possibly are we the only one interested in getting IRQ with NRFDoctor. So is a good news you confirm it works. Can I assume you use same W5100 HW shield as mine and that you have for HW connections: W5100 (CS/MOSI/MISO/CLK) wired respectively on HW SPI (10,11,12,13) NRF24 also on HW SPI for (MOSI/MISO/CLK) only and differentiated CS/CE/IRQ on for instance respectively 6/5/2 Regards and thanks for these precious informations that will help me saving time. Regards