Re: [Discuss-gnuradio] gr-uhd timed command messages

[Marcus Müller]

Hi Nigel,

>             d_rxCommand = pmt::dict_add(d_rxCommand, pmt::mp("time"), 
> pmt::mp(0.5));

Timestamps aren't just doubles for UHD; they ought to be [1]

> timestamp: A pair composed of (long full_secs, double frac_secs).
Similar to uhd::time_spec_t.

So your timestamp needs to be a pair of long, double

pmt_t timestamp = pmt::make_pair(pmt::from_long(0), pmt::from_double(0.5));
d_rxCommand = pmt::dict_add(d_rxCommand, pmt::mp("time"), timestamp);

if I'm not mistaken.

Best regards,
Marcus

[1] https://gnuradio.org/doc/doxygen/page_uhd.html#uhd_command_syntax_cmds
On 04.03.2016 01:39, Nigel Steed wrote:
> Hi Martin,
>
> I have put the following code into my block.
>
>
>       d_rxCommand = pmt::make_dict();
>              d_rxCommand = pmt::dict_add(d_rxCommand, pmt::mp("time"), 
> pmt::mp(0.5));
>              message_port_pub(pmt::mp("rx_freq_msg"), d_rxCommand );
>
> It sends the message to the UHD Sink. But I get this error at run time:
>
>       thread[thread-per-block[5]: <block gr uhd usrp source (1)>]: pmt_cdr: 
> wrong_type : 1
>
> Any ideas ? I am trying to auto step the frequencies, and currently have my 
> own block to generate frequency messages which works fine. I am now trying to 
> implement the time commands. Is there any other way to do it ?
>
> Thanks,
>
> Nigel
>
>
>
> -----Original Message-----
> From: address@hidden [mailto:address@hidden On Behalf Of Martin Braun
> Sent: Wednesday, March 2, 2016 9:24 PM
> To: address@hidden
> Subject: Re: [Discuss-gnuradio] gr-uhd timed command messages
>
> When using messages, simply add a 'time' key to the command dictionary, and 
> it will be set for the command you're calling. The time stamp value, is a 
> long/double pair, for full and fractional time. Example:
>
> {'freq': 1e9, 'time': (100, 0.1)}
>
> If this is your message, it will set the frequency to 1 GHz at time 100.1.
>
> Cheers,
> Martin
>
>
>
> On 03/02/2016 05:46 AM, Nigel Steed wrote:
>> Hi,
>>
>>  
>>
>> Anyone know or managed to implement the time command using a message 
>> port to the UHD Source Block ?
>>
>>  
>>
>> I believe time commands are not implemented in the latest GNURadio 
>> gr-uhd ? Is that correct ?
>>
>>  
>>
>> Thanks,
>>
>>  
>>
>> Nigel
>>
>>
>>
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>
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