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我正在使用到 UHD 的 GNURadio python 接口,我正在尝试设置一个特定的时间来开始收集样本并收集特定数量的样本或在特定时间停止样本的收集。本质上,创建样本的定时快照。这类似于 C++ Ettus UHD 示例“rx_timed_sample”。

我可以让流程图在特定时间开始,但我似乎无法让它在特定时间停止(至少不会导致溢出)。我也尝试过进行有限采集,这很有效,但我无法让它在特定时间开始。所以我有点迷茫下一步该做什么。

这是我对有限采集的尝试(似乎只是忽略了开始时间并收集了 0 个样本):

num_samples = 1000

usrp = uhd.usrp_source(
    ",".join(("", "")),
    uhd.stream_args(
        cpu_format="fc32",
        channels=range(1),
    ),
)

...

usrp.set_start_time(absolute_start_time)
samples = usrp.finite_acquisition(num_samples)

我还尝试了以下一些组合但没有成功(TypeError:在方法'usrp_source_sptr_issue_stream_cmd'中,类型为'::uhd::stream_cmd_t const &'的参数2):

usrp.set_command_time(absolute_start_time)
usrp.issue_stream_cmd(uhd.stream_cmd.STREAM_MODE_NUM_SAMPS_AND_DONE)

我还在流程图中尝试了以下内容:

...
usrp = flowgrah.uhd_usrp_source_0
absolute_start_time = uhd.uhd_swig.time_spec_t(start_time)
usrp.set_start_time(absolute_start_time)

flowgrah.start()

stop_cmd = uhd.stream_cmd(uhd.stream_cmd.STREAM_MODE_STOP_CONTINUOUS)
absolute_stop_time = absolute_start_time + uhd.uhd_swig.time_spec_t(collection_time)

usrp.set_command_time(absolute_stop_time)
usrp.issue_stream_cmd(stop_cmd)

无论出于何种原因,在超过 0.02 秒的收集时间的情况下,生成的流程图始终会溢出。

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1 回答 1

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I was running into a similar issue and solved it by using the head block.

Here's a simple example which saves 10,000 samples from a sine wave source then exits.

#!/usr/bin/env python
# Evan Widloski - 2017-09-03
# Logging test in gnuradio

from gnuradio import gr
from gnuradio import blocks
from gnuradio import analog

class top_block(gr.top_block):
    def __init__(self, output):
        gr.top_block.__init__(self)

        sample_rate = 32e3
        num_samples = 10000
        ampl = 1

        source = analog.sig_source_f(sample_rate, analog.GR_SIN_WAVE, 100, ampl)
        head = blocks.head(4, num_samples)
        sink = blocks.file_sink(4, output)

        self.connect(source, head)
        self.connect(head, sink)

if __name__ == '__main__':
    try:
        top_block('/tmp/out').run()
    except KeyboardInterrupt:
        pass
于 2017-09-04T05:03:35.973 回答