|
From: | Marcus D. Leech |
Subject: | Re: [Discuss-gnuradio] what is the update rate of signal probe/probe function ? |
Date: | Thu, 10 Mar 2016 13:20:16 -0500 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 |
On 03/10/2016 10:53 AM, apchar wrote:
If you want to process signals at the sample rate, you need to use existing blocks, or write one. The probe infrastructure is designed for occasional probing of the sample stream, not as a replacement for writing an actual sample-processing block. A "probe" block has a probe function, typically, called "level" which returns the current sample value at the time the probe is called. A "function probe" block is a way of creating a thread within the generated python that simple polls this function at whatever (reasonable) rate you request. If you look at the generated code for function probe, it's just a while loop, with a "sleep" at the bottom of it corresponding to your desired rate. Asking for a rate beyond a few 10s per second is not going to work very well, both because this is Python, and because achievable wake-up rates even on a modern CPU with a modern kernel like linux aren't going to be anywhere close to the kinds of rates required to process at typical input sample rates. |
[Prev in Thread] | Current Thread | [Next in Thread] |