[hpsdr] Penelope PTT

[Gerd Loch]

Hi Phil,

I have interrupts in the usb datastream (audio is popping) for whatever
reason. 
I found that these interrupts in the usb-datastream (fifo empty) lead to a
condition where HAVE_SYNC is 0. As PTT_OUT directly depends on HAVE_SYNC the
ptt-relais is switched off for some milliseconds. It can be avoided by
delaying the ptt switch off not before HAVE_SYNC is 0 longer than xx sec.

In my new version PTT_OUT is switching off 1,4 sec after i.e. you disconnect
the usb cable. My ptt-relais is now steady.

Here the code:

assign have_sync = (got_sync && (Rx_used > 3)) ? 1'b1 : 1'b0; 
 

reg have_sync_relais;
reg [26:0] valid_count; // there will be a delay of 1,4s
 
always @ (posedge IFCLK) begin
        if (!have_sync)
         begin
          if(!valid_count[26])
             begin
              valid_count <= valid_count + 26'b1;
             end      
          else
             begin
              have_sync_relais <=0;
             end
         end
        else //hat sync
         begin
          have_sync_relais <=1;
          valid_count <= 26'b0;
         end
end
 
 
and later in Code:
 
assign PTT_out = (Rx_control_0[0] && have_sync_relais) ? 1'b1 : 1'b0; //
inhibit PTT if no sync
 
 

73, Gerd
DJ8AY




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