; ; $Header: C:\\ham\\evm/RCS/p3d.asm,v 1.4 2000/10/05 16:59:04 dbraun Exp dbraun $ ; ; $Log: p3d.asm,v $ ; Revision 1.4 2000/10/05 16:59:04 dbraun ; Works! Problem is that adjusting Rx phase messes up Tx phase. ; Problem also exists in g3ruh.asm. ; ; Revision 1.3 2000/10/05 16:17:53 dbraun ; Added more SPYs. Realized true cause of problems. ; ; Revision 1.2 2000/10/04 13:57:20 dbraun ; Should work, but doesn't :-( ; ; Revision 1.1 2000/10/02 17:04:06 dbraun ; Initial revision ; ; ; Initialized from: ; C:\\ham\\evm/RCS/g3ruh.asm ; Revision 1.9 2000/08/03 19:17:47 dbraun ; page 132,79 opt rc opt mu title 'G3RUH-style P3D telemetry demodulator' ;*************************************************************** ;* This program is derived from: ;* G3RUH.ASM -- 9600 bit/s G3RUH modem * ;* * ;* 9600 bit/s two level PAM demodulation with fixed rate * ;* sampling and adaptive equalizer. * ;* * ;* PAM demodulation is based on some ideas presented in book * ;* Lee, E., A., Messerschmitt, D., G.: * ;* "Digital Communication", * ;* Kluwer, 1988 * ;* * ;* Symbol synchronization is base on the article * ;* Mueller, K., H., Mller, M.: * ;* "Timing Recovery in Digital Synchronous Data * ;* Receivers", * ;* IEEE Trans. on Comm., Vol. COM-23, No. 5, May 1976 * ;* * ;* This module uses registers as follows: * ;* r0 - general purpose (temporary use) * ;* r1 - general purpose (temporary use) * ;* r2 - sample buffer pointer * ;* r3 - pointer into buffer for xmit data (NA1DB) ;* r4 - output filter pointer * ;* r6 - general purpose (temporary use) * ;* * ;* Copyright (C) 1993-1996 by Alef Null. All rights reserved. * ;* Author(s): Jarkko Vuori, OH2LNS * ;* Modification(s): * ;* 01.01.1996 Added support for both left and right * ;* channels * ;* 22.03.1996 Modified for the new SPY program * ;*************************************************************** ; User controllable parameters SPY set 0 ; Set to 1 for SPY mode. SpyS2 set 0 ; Spy on the s2 variable. SpyS1 set 0 ; Spy on the s1 variable. SpyAgc set 0 ; Spy on AGC gain SpyD1 set 0 ; Spy on RX data signal, post-decision SpyRxData set 0 ; Spy on final RX data bits SpyTxSig set 0 ; Spy on TX data signal, post-scrambler SpyEyeFilt set 0 ; Spy on DCD eye filter variable OLevel set 0.10 ; output signal level (in rms volts) RxGain set 9.0 ; Codec input gain in dB, set to match radio. RightAudioChannel set 0 ; left codec channel (0)/right codec channel (1) DoOutput set 1 ; Set to non-zero if we should "transmit" data. ; If set to 0, we will transmit all 1 (mark) bits. ; Note: The PTT line is ever actually activated. SCIBaudRate set 9600 ; The SCI baud rate is reset only if necessary. SendFixedMessage set 1 ; If set, a canned message will be transmitted, ; and the SCI RX data will be left alone. nolist include 'leonid' include 'ioequlc' list ; Program parameters buflen equ 256 ; codec sample buffer length fs equ 48000.0 ; sampling frequency fd equ 9600.0 ; decision rate I equ 2 ; interpolation factor D equ 5 ; decimation factor 48k*(I/D)=19.2k ; AGC refLev equ 0.6 ; reference level for AGC agcN equ 15 ; agc analyse block length agcGain equ 100.0 ; agc integrator gain ; symbol synchro rwfc0 equ 0.99 ; random walk filter coefficient (carrier off) rwfc1 equ 0.3 ; random walk filter coefficient (carrier on) ; DCD DCDFil equ 0.02 ; decision error IIR LPF coefficient DCDN equ @cvi(0.3*fd+.5) ; delay (in s) after DCD off ; G3RUH specific poly equ $10800 ; G3RUH,K9NG scrambler polynomial (x^17 + x^12 + 1) ; flags car equ 1 ; carrier on/off ; ASCII constants LF equ 10 CR equ 13 ; macro for DCD output handling ; O2 for both channels carled macro mode b\mode #13,x:$ffe4 ; N1OWU: was bit 2, I made bit 13 to match bpsk1200 endm YellowLED macro mode ;CAT line (a yellow LED connected) b\mode #3,X:$FFE4 endm OrangeLED macro mode ; (an orange LED connected) b\mode #14,X:$FFE4 endm ; first order high-pass IIR filter ; input in a, output in a ; frq is -3dB point (fc/fs) hpass macro acc,frq,store c1 set -1.0/@cos(6.28319*frq)*(1.0-@sin(6.28319*frq)) move acc,x0 move #>(1.0-c1)/2.0,y0 mpyr x0,y0,acc x:c1,y0 macr -x0,y0,acc move acc,x:1,x1 tlo x0,a move a,y:agcN,x1 move a,y:@pow(2,-5)*agcGain/(fs/agcN),x1 ; rectangular integration move b,x0 move y:(poly<<1)|1,x0 eor x0,b unscram lsr b move b1,x: if !SPY bset #1,X:m_pcd endif if SPY&&SpyRxData move #0.5,a jsr poly,x0 jcc <_gb2 eor x0,a _gb2 move a1,x:DCDN,x0 jgt _car2 move x0,y:1,x0 ; no carrier after DCDN symbols sub x0,b #rwfc0,x0 move b,y: OrangeLED clr .else OrangeLED set .endi ; all this again, sigh! jmp iftaps,x0 sub x0,a #>icoeffs,x0 cmp x0,a #>ifbnks*iftaps,x0 jhs <_adv1 move (r2)+ add x0,a (r2)+n2 ; jumped over the first taps set _adv1 add x0,a a,x:iftaps,x0 add x0,a #>icoeffs+ifbnks*iftaps,x0 cmp x0,a #>ifbnks*iftaps,x0 jlo <_ret1 move (r2)- sub x0,a (r2)-n2 ; jumped over the first taps set _ret1 add x0,a a,x: ; Get a new char, and return a zero async start bit. jsr move #>9,b ; Send (after start bit) 8 data + 1 stop bits. move b,X:AsyncEncodeBitCount bset #8,a1 ; Set the stop bit move a1,X:AsyncEncodeShiftReg andi #$FE,ccr ; Clear carry rts ;carry = next bit to be transmitted .endi ; If C=1, there is no new data, and we will keep ; sending a stop bit (1) until new data arrives. .else ; Return next bit of current char. move #>1,x0 sub x0,b lsr a1 b,X:AsyncEncodeBitCount move a1,X:AsyncEncodeShiftReg rts ;carry = next bit to be transmitted .endi ReadChar if SendFixedMessage move #$1FFFF,m0 move X:FixedMessagePtr,r0 clr a move Y:(r0)+,x0 eor x0,a .if move #FixedMessage,r0 nop move Y:(r0)+,x0 .endi move r0,X:FixedMessagePtr andi #$FE,ccr ; Clear carry else if SPY ori #$01,ccr ; Set carry: No character else lookc 0 endif endif .if move x0,a1 ;andi #$FE,ccr ; Clear carry .endi rts ;carry = 0 if new character has been read from the terminal ;a1 = new character if SPY SpyA move a10,L:'S',a cmp x0,a jne 'P',x0 putc move #>0,x0 ; send a 0 meaning non-complex data putc move #>512,a Spy_copy move #>1,x0 sub x0,a move a,X:=@cvi(LastY) org L:LastX else org L:LastY endif if SPY SpySave dc 0,0 SpyCount dc 0 SpyTmp ds 1 endif buffer dsm buflen*4 end