On Thu, Sep 22, 2011 at 10:11 AM, Zhonghua
<address@hidden> wrote:
Hi every one,
Now I am trying to use gr.buffer. I wrote some very simple codes to test how to use gr.buffer correctly. The main codes are as below:
self.u=gr.sig_source_c(1e4,gr.GR_SIN_WAVE,1e3,1) #to create a sin source
self.buf=gr.buffer(1000,gr.sizeof_gr_complex,self.u) #create a buffer by applying gr.buffer
self.csink=gr.vector_sink_c()
self.connect(self.buf,self.csink) #send buffer volume to the sink
But unfortunately, I got a despondent error reply says: in method 'buffer', argument 3 of type 'gr_block_sptr'. I looked up the gr_buffer class and found that the so called argument 3 is a link to a block which writes data to this buffer. As my understanding, the sig_source block should write data to the buffer so I write self.buf as above way. From the error hint, I ever thought perhaps the error just comes from the incorrect type. Because the sin_source object is pointed by the pointer type of "gr_sin_source_c_sptr". But how can I get an object that merely inherited from gr.block class? I tried to construct a class inherits from gr.block but there exists another error says that "'module' object has no attribute 'block' ".
I checked the internet but found nothing helpful. A surprising fact is that looks no one ever used gr.buffer in gnuradio by adopting python way. Is there anybody know how to use it correctly?
Your instruction is fairly appreciated.
Br,
Zhonghua
The gr.buffer is not meant to be used this way. It's the data structure used in the input and output ports of the blocks to move data. There's no reason to use it in a flowgraph or anything like that.
What's your reason for wanting a buffer there in the first place? It's likely that there is an actual block meant for your purpose.
Tom