https://devzone.nordicsemi.com/f/nordic-q-a/4632/intializtion-time-cup-reset-cpu-initialization-rf-setting-of-nrf51822Hello, We developed the energy harvest application equipment with the HRM1017 module. The function is every simply as follows: After initialization, CPU scans 4 I/O ports (pulled up) and read the status (High or Low). If the port is low then iten-USTelligent Community 13Thu, 18 Dec 2014 03:08:11 GMThttps://devzone.nordicsemi.com/thread/16465?ContentTypeID=1Thu, 18 Dec 2014 03:08:11 GMT137ad170-7792-4731-bb38-c0d22fbe4515:55a7667d-abaa-4724-8789-01e305d6dd5dH_Nakamura<p>Hello,</p> <p>Thanks for your answer. The supply voltage is 3v and the module doesn&#39;t use the extarnal crystal Are there any other possibility cause?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/16466?ContentTypeID=1Mon, 01 Dec 2014 11:54:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6fec0a17-e78f-45bd-bbee-3fb2cfb034e9Stefan Birnir Sverrisson<p>Hi</p> <p>What has the most effect on the nRF51 startup time are two things:</p> <ul> <li>The supply voltage. The startup time is longer when using low supply voltages, i.e. ~1.8V.</li> <li>When initializing the S110 softdevice with external 32kHz crystal, startup of the crystal can take a long time, up to 1 second worst case.</li> </ul> <p>So a solution would be to start up the softdevice with the internal 32kHz RC instead, and/or to use higher supply voltage, e.g. 3.0V</p><div style="clear:both;"></div>