Re: [Discuss-gnuradio] questions related to msgq_insert

On Wed, Mar 02, 2011 at 09:18:39PM -0500, Yan Nie wrote:
> Dear all,
>
> I'm using the message_source to generate the source, connecting it with a multiply_const block to configure the amplitude for the signal. 
>
> The message_source is created by the following:
> data = gr.message_source(sizeof_char, 2)

This means your input items are 1 byte in length (=8 bit).

> msgq = data.msgq()
>
> When the msg is inserted as a tail of the msgq while the flow graph is running, the msg is inserted using insert_tail(msg). If my understanding serves me right, if only insert the msg once, it suppose to be send once. In my case, however, the msg is sent 10 times. (the set_amp is defined in the tb block to change the amplitude of the signal while tb is running) Could anyone help me to see what causes the problem?
> The code related msgq_insert in main thread is as followed:
> try:
>   while 1:
>            i = 1 
>            tb.set_amplitude(5000)
>            msg_13bit = gr.message_from_string(payload_13bit)

Is msg_13bit really only 8 bits large? Have you checked the message sent
is what you wanted it do be?

>            tb._ls.msgq.insert_tail(msg_13bit)
>            tb.set_amplitude(0)
>            while(i < 50)
>                    msg_stop = gr.message_from_string(payload_stop)
>                    tb._ls.msgq.insert_tail(msg_stop)

Same here.

>                    i += 1
>
> Really appreciate any of your help!
> Thanks,
> Yan

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