https://devzone.nordicsemi.com/f/nordic-q-a/15360/what-does-ff-command-doI&#39;m new to nrf8001 I&#39;m trying to understand an existing example. in this example after sending set up commands generated by nrfgo studio , program sends 9 byte of 0xff command (invalid aci command) , waits for 20 ms and then send 4 byte of that againen-USTelligent Community 13Tue, 02 Aug 2016 11:24:07 GMThttps://devzone.nordicsemi.com/thread/58693?ContentTypeID=1Tue, 02 Aug 2016 11:24:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d4a9aca5-9a06-4a2b-85fe-8a1b5f899617run_ar<p>Please consider using the nordic <a href="https://github.com/NordicSemiconductor/ble-sdk-arduino/tree/master/libraries/BLE/examples">SDK examples</a>. I don&#39;t understand why you would be sending 0xff to the chip, if you are not sending valid commands you should at least make sure the length field is 0x00. Please refere to the Product specification for valid commands.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/58692?ContentTypeID=1Thu, 28 Jul 2016 07:28:26 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c69c4c88-2a6c-4ac7-8574-41b562512181mj seyyedi<p>@hungbui I edited the question</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/58691?ContentTypeID=1Wed, 27 Jul 2016 10:37:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:78bcc6f1-111d-4c37-ba82-174ee4795906Hung Bui<p>@mj: which example are you following ? Could you post the code ?</p><div style="clear:both;"></div>