Re: [Discuss-gnuradio] Fwd: Write a source block in python

[Thanasis Balafoutis]

Thank you Doug!

return -1 indeed cause the flowgraph to exit. Is there any trick to stop also the execution on my program (after 1 sec)?

Another problem I have is that the output is always 32768 bytes
def work(self, input_items, output_items):
........
return len(output_items[0])

If I change it to this:
   return len(output_items[0][:len(test)])

my output becomes empty

Is it possible to get in the output the exact number of bytes of my helloMsg parameter?

2015-01-22 23:31 GMT+02:00 Anderson, Douglas J. <address@hidden>:

I think having the work fn return "-1" will cause the flowgraph to exit, so you could potentially have a "self.count = 1" in __init__ and then when you've output >= self.count, have work return -1

-Doug

Douglas Anderson | Intern

DOC/NTIA/ITS-T | 325 Broadway St., Boulder, CO 80305 | P: 303 497 3582

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From: discuss-gnuradio-bounces+danderson=address@hidden [discuss-gnuradio-bounces+danderson=address@hidden] on behalf of Thanasis Balafoutis [address@hidden]
Sent: Thursday, January 22, 2015 2:12 PM
To: address@hidden
Subject: [Discuss-gnuradio] Fwd: Write a source block in python

Hi

I wrote a simple source block that reads a string (as a parameter) and outputs the corresponding array of bytes.

Here is the code:

class myblock(gr.sync_block):

    def __init__(self, helloMsg):
        gr.sync_block.__init__(self,
            name="myblock",
            in_sig=None,
            out_sig=[numpy.byte])
        self.helloMsg = helloMsg

    def work(self, input_items, output_items):
        out = output_items[0]
       
        test = array.array('B',self.helloMsg)
        for j in range(len(test)):
           out[j] = test[j]
        return len(output_items[0][:len(test)])

In the output I repeatedly get the helloMsg. (it seems that the work() function is always running)

Is it possible to get in the output my helloMsg only one time (or a specific amount of times) and then stop the execution of the flowgraph?

Thank you in advance!

Thanasis