title: Raspberry Pi3 BLE as Central device receiving just one packet per connection interval - gatttool/hcitool
body: <p>i would appreciate if someone can explain one issue i'm experiencing with Raspberry Pi 3 model B acting as a Central device on a BLE connection with a Peripheral device. </p>
  
  <p>First, i successsfully connect both devices and enable notifications on the Central device using the folllowing hcitool/gatttool commands:</p>
  
  <pre><code>sudo hciconfig hci0 up
  sudo gatttool --adapter=hci0 --device=XX:XX:XX:XX:XX:XX --adr_type=random --mtu=23 -I
  [][LE]&gt; connect
  [][LE]&gt; char-write-req 0x000c 0100
  </code></pre>
  
  <p>After that, i started receiving notifications on the Raspberry Pi3 model B, and using a BLE sniffer, i check that it receives 5 BLE packets with notified values per connection interval (that is OK), which is established by default to 54 (67,5ms). However, once both devices are connected, i update the connection parameters in order to modify the connection interval to, i.e. 24 (30ms) using the following hcitool command:</p>
  
  <pre><code>sudo hcitool lecup --handle=XX --min=24 --max=24
  </code></pre>
  
  <p>And the issue i found is that, once the connection parameters are updated, i checked that the Raspberry Pi3 model B starts receiving just 1 BLE packet per connection interval (That is not OK). The same behavioral is observed updating the conection parameters to higher values of connection interval, i.e. 800 (1s).</p>
  
  <p>Could anyone give me an explanation of that issue? In addition, could anyone try to reproduce this procedure and check if the same issue is observed?</p>
  
  <p>Thanks</p>