Thread Details

  • State Verified Answer
  • Replies 8 replies
  • Subscribers 61 subscribers
  • Views 1493 views
  • Users 0 members are here 

        

            Post
             Go back to editing
        

    

    


    

    









		


















	
	
			
	
			
		
	
	
		

	    
	    
	    		
Get in RX the same values of TX

		
	
				

			

									
					    Daniel_Camara
					
							

            
            			
				
									
											
			
			
				
			
			
			    	
			                    
                
				                on Apr 22, 2015 
				
			
			
		

		
		                     
				
        		

		    
		    		    
		    			

			    
Hi people,

 
There is a way to send a data in the TX and receive the same in the RX?  I mean if I put a cable between TX A and RX A and send a value in I and another in Q, there is a way to get them back on the RX A I/Q?  I am developing a IEEE 802.15.4 transceiver, and for testing, at least in the begging would be nice to be able to do that, send something and get the same the other side. 

 
 I tried to change the ad9361-iiostream.c to send always the same data, RX and TX in the same frequency, and on the RX compare the received I/Q to see if was the same... but I didn't manage to do it.  Well it makes sense not being able to, the process is too fast, so the time you say send this and you start reading it is possible that you will not read the same thing you just sent, even more because, as far as I understood the buffers in the middle would make this  synchronization a nightmare, even with different threads for the send and receive. 

 
 Nevertheless, I would know if I can do it, somehow to be able to test my transceiver. 

 
   Best regards...

 
          Daniel

			

			
									
		                             
                        
		


				
				        
        		

			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		


        
        
        
    
					

			





















	

	

					



			








	
	
	
	



Parents
	
    
	

  • 
	
    



	
		
	
	



    
	
    
		
    
							
					
    
		
    
		    
		    		    
			
				
									
							        
			
			
			
            
						
                            
            
            				
            
                on Apr 23, 2015 12:26 PM
            
            
						
			            		
    
		
										0
					
	
    

		
		
    
		
    
                                
                                                            
    
					
    Hi Michael,
    
 
      Thanks for the link that really answers the question about the loss in precision.  But there is a way to set the size of the buffer for the loopback? It seems the buffer is limited to 4 symbols. 
    
 
       I spend some time trying to understand again and I perceived (yes I am kind of slow ) that in fact it just repeats some values, over and over. I changed the code to, instead of a sinusoid just send a number count and then the result is even clearer.... The loop back buffer has a size that I should set somewhere? I tried to find in the osciloscope but I didn't managed to. Any ideas?
    
 
    Just for the sake of the example, here, the RX buffer is a sequence of FE, FF, FC, FD: 
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=20,Q=30 :: 300020
    
 
    i:2 I=40,Q=50 :: 500040
    
 
    i:3 I=60,Q=70 :: 700060
    
 
    i:4 I=80,Q=90 :: 900080
    
 
    i:5 I=A0,Q=B0 :: B000A0
    
 
    i:6 I=C0,Q=D0 :: D000C0
    
 
    i:7 I=E0,Q=F0 :: F000E0
    
 
    i:8 I=100,Q=110 :: 1100100
    
 
    i:9 I=120,Q=130 :: 1300120
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:1 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:2 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:3 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:4 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:5 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:6 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:7 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:8 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:9 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    --------------------------
    
 
    ////////////////////////////////////
    
 
    If I change it to  my sinusoid again.... than the first time it flushes the old buffer (as expected), and after it gets locked into a sequence of the sinusoid. (0000, FFFF, FA82, 57E). 
    
 
    //////////////////////////////////////
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:2 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:3 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:4 I=0,Q=10 :: 100000
    
 
    i:5 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:6 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:7 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:8 I=0,Q=10 :: 100000
    
 
    i:9 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:1 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:2 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:3 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:4 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:5 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:6 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:7 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:8 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:9 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
        RX     1.05 MSmp, TX     1.05 MSmp
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:2 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:3 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:4 I=0,Q=10 :: 100000
    
 
    i:5 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:6 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:7 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:8 I=0,Q=10 :: 100000
    
 
    i:9 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:1 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:2 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:3 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:4 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:5 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:6 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:7 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:8 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:9 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
						
				
				
		
		
    
			
		
    
	
    

    

    • 

	




Reply

    


  • 
	
    



	
		
	
	



    
	
    
		
    
							
					
    
		
    
		    
		    		    
			
				
									
							        
			
			
			
            
						
                            
            
            				
            
                on Apr 23, 2015 12:26 PM
            
            
						
			            		
    
		
										0
					
	
    

		
		
    
		
    
                                
                                                            
    
					
    Hi Michael,
    
 
      Thanks for the link that really answers the question about the loss in precision.  But there is a way to set the size of the buffer for the loopback? It seems the buffer is limited to 4 symbols. 
    
 
       I spend some time trying to understand again and I perceived (yes I am kind of slow ) that in fact it just repeats some values, over and over. I changed the code to, instead of a sinusoid just send a number count and then the result is even clearer.... The loop back buffer has a size that I should set somewhere? I tried to find in the osciloscope but I didn't managed to. Any ideas?
    
 
    Just for the sake of the example, here, the RX buffer is a sequence of FE, FF, FC, FD: 
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=20,Q=30 :: 300020
    
 
    i:2 I=40,Q=50 :: 500040
    
 
    i:3 I=60,Q=70 :: 700060
    
 
    i:4 I=80,Q=90 :: 900080
    
 
    i:5 I=A0,Q=B0 :: B000A0
    
 
    i:6 I=C0,Q=D0 :: D000C0
    
 
    i:7 I=E0,Q=F0 :: F000E0
    
 
    i:8 I=100,Q=110 :: 1100100
    
 
    i:9 I=120,Q=130 :: 1300120
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:1 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:2 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:3 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:4 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:5 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:6 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:7 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:8 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:9 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    --------------------------
    
 
    ////////////////////////////////////
    
 
    If I change it to  my sinusoid again.... than the first time it flushes the old buffer (as expected), and after it gets locked into a sequence of the sinusoid. (0000, FFFF, FA82, 57E). 
    
 
    //////////////////////////////////////
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:2 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:3 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:4 I=0,Q=10 :: 100000
    
 
    i:5 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:6 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:7 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:8 I=0,Q=10 :: 100000
    
 
    i:9 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:1 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:2 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:3 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:4 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:5 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:6 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:7 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
    i:8 I_i=FFFFFFFE,Q_i=FFFFFFFF :: FFFFFFFE
    
 
    i:9 I_i=FFFFFFFC,Q_i=FFFFFFFD :: FFFDFFFC
    
 
        RX     1.05 MSmp, TX     1.05 MSmp
    
 
    --- To Send Values --- 
    
 
    i:0 I=0,Q=10 :: 100000
    
 
    i:1 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:2 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:3 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:4 I=0,Q=10 :: 100000
    
 
    i:5 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:6 I=FFFFFFF0,Q=0 :: FFF0
    
 
    i:7 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    i:8 I=0,Q=10 :: 100000
    
 
    i:9 I=FFFFA820,Q=57E0 :: 57E0A820
    
 
    --- Received Values  rx0_i --- 
    
 
    i:0 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:1 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:2 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:3 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:4 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:5 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:6 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:7 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
 
    i:8 I_i=FFFFFFFF,Q_i=0 :: FFFF
    
 
    i:9 I_i=FFFFFA82,Q_i=57E :: 57EFA82
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
						
				
				
		
		
    
			
		
    
	
    

    

    • 





Children
	
No Data