<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<div class="moz-cite-prefix">Hi Sebastian,</div>
<div class="moz-cite-prefix">since the hackrf is half-duplex and has
no timestamp support (only continuous streaming) the buffer size
was chosen at the time to provide a reasonable tradeoff between
latency and performance for higher sample rates - I suppose you
could just decrease it if that is the problem, but there is still
no way to just send something immediately, there will always be a
considerable latency between the host and the rf output.</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">-Eric<br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Am 09.12.2020 um 13:23 schrieb
Sebastian Böhm:<br>
</div>
<blockquote type="cite"
cite="mid:0b9d4c0e-eefd-cf5f-c23c-6eb94791a2fc@b-tu.de">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Does anyone have any idea what could be the reason for this
behavior?<br>
</p>
<div class="moz-cite-prefix">Am 01.12.2020 um 16:28 schrieb
Sebastian Böhm:<br>
</div>
<blockquote type="cite"
cite="mid:c6a553b6-ee76-d23c-2f49-40197a4ec183@b-tu.de">
<meta http-equiv="content-type" content="text/html;
charset=UTF-8">
Hi,<br>
<br>
i try to transmit 2.48 ghz radio packets (beacons) at a fixed
time interval (e.g. every 1 s) via hackrf using the osmocom sink
in gnuradio. Without exception, the beacons are all received by
my sniffer "golden device" hardware, but burst.<br>
<br>
It seems that the packets are only transferred via USB to the
hackrf device hardware when the buffer with the fixed BUF_LEN
262144 (32*16*512) is completely filled. For my setup this are
e.g. 18 beacon frames, which are transmitted as burst. When I
look at the USB interface, I can see this burst of data every 18
seconds in a full USB request block (URB) of size 262144 byte.
All other URBs (also of size 262144 - every approx. 200us)
transferred via USB are filled with zeros only. So this burst
behavior should be caused by gnuradio.<br>
<br>
How can I achieve that the complex data of the osmocom sink's
input is immediately (with the next URB) transferred to the
hackrf hardware? Am I missing any options of the GRC module?<br>
<br>
Thank You in advance!<br>
<br>
Regards,<br>
Sebastian<br>
<div class="moz-signature">-- <br>
<font face="monospace" color="Gray">
__________________________________________________________<br>
<br>
Sebastian Boehm<br>
Brandenburg University of Technology Cottbus - Senftenberg<br>
Computer Networks Communication Systems Group<br>
<br>
E-Mail: <a href="mailto:Sebastian.Boehm@b-tu.de"
moz-do-not-send="true">sebastian.boehm@b-tu.de</a><br>
<br>
P.O. Box: 10 13 44<br>
D-03013 Cottbus<br>
GERMANY<br>
</font></div>
</blockquote>
</blockquote>
<p><br>
</p>
</body>
</html>