From eb401fb367ea6c90c5f3f2f2765d1cb846b95f87 Mon Sep 17 00:00:00 2001 From: drowe67 Date: Tue, 21 Feb 2017 21:33:15 +0000 Subject: [PATCH] cleaned up README a bit, added alsa loopback instructions git-svn-id: https://svn.code.sf.net/p/freetel/code@3044 01035d8c-6547-0410-b346-abe4f91aad63 --- freedv-dev/README.txt | 120 ++++++------------------------------------ 1 file changed, 15 insertions(+), 105 deletions(-) diff --git a/freedv-dev/README.txt b/freedv-dev/README.txt index 311af470..a91059eb 100644 --- a/freedv-dev/README.txt +++ b/freedv-dev/README.txt @@ -172,111 +172,6 @@ configure emacs: (setq c-basic-offset 4) ))) -==== -TODO -==== - -[ ] Open R&D questions - + Goal is to develop an open source DV mode that performs comparably to SSB - [ ] Does 700 perform OK next to SSB? - + approx same tx pk level (hard to measure exactly) - + try some low SNR channels - + try some fast fading/nasty channels - [ ] Is 700 speech quality acceptable? - -[X] test frames - [X] freedv API support - [X] BER displayed on GUI for 700 and 1600 - [X] plot error patterns for 700 and 1600 - + callback for error patterns, or poll via stats interface - [X] plot error histograms for 700 and 1600 - + map bit error to carrier, have done this in tcohpsk? - + how to reset histogram? On error reset? - + histogram screen ... new code? - + test with filter - -[X] Bugs - [X] resync issue - [X] equalise power on 700 and 1600 - [X] research real and complex PAPR - [X] waterfall and spectrum in analog mode - [X] The waterfall in analog mode appears to quit working sometimes? - - [X] On TX, intermittently PTT will cause signal to be heard in speakers. Toggle PTT or - Stop/Start toggle and then starts working. - [X] Squelch control on 1600 mode will not open up squelch to 0 (appears to be around 2 dB) - [X] space bar keys PTT when entering text info box - [X] checksum based txt reception - + only print if valid - [X] IC7200 audio breakup - [ ] short varicode doesn't work - + #ifdef-ed out for now - + cld be broken in freedv_api - [X] On 700 audio sounds tinny and clicky when out of sync compared to 1600 why? - + clue: only when analog not pressed - + this was 7.5 to 8kHz interpolator bug - [X] spectrum and waterfall scale changes when analog pressed - [X] ocassional test frames error counter goes crazy - [ ] old Waterfall AGC - [ ] 700 syncs up to 1000Hz sine waves - + shouldn't trigger sync logic, will be a problem with carriers - [ ] "clip" led, encourage people to adjust gain to hit that occ when speaking - [ ] Win32 record from radio time - [ ] Stuttering with squelch off - + Rpeorted by Mark VK5QI, can we repeat? - -[ ] FreeDV 700 improvements - [ ] bpf filter after clipping to remove clicks - [ ] tcohpsk first, measure PAPR, impl loss - [ ] error masking - [ ] C version - [ ] training off air? Switchable? - [ ] excitation params - [ ] training - [ ] plotting other demod stats like ch ampl and phase ests - [ ] profile with perf, different libresample routine - [ ] check for occassional freedv 700 loss of sync - + scatter seems to jump - [ ] switchable diversity (narrowband) option - + measure difference on a few channels - + blog - [ ] slow mode at half speed rather than repeating, or tx twice and sum - [ ] Can freedv remove ambient rf with a simple second Rx? - [ ] presence, posting to web site - [ ] explore relaxing sync 700 thresh - [ ] longer record files - [ ] two vertical lines in the waterfall representing the band limits of the 700B mode - -[X] win32 - [X] X-compile works - [X] basic installer - [X] Win32 installer - + Richard has taken care of this - -[ ] Small fixes - [X] Playfile bug - [X] running again - [X] bump ver number - [X] long varicode default - [X] option to _not_ require checksum, on by default - [X] default squelch 2dB - [X] scatter diagram tweaks - + e.g. meaningful plots on fading channels in real time - [X] agc with hysteresis - + changed to log steps - [X] longer persistance - + changed to 6 seconds - [X] diversity addtions on 700 - + still not real obvious on plot - + might be useful to make this switchable - [X] scatter diagram different colours/carrier - [X] remember what mode you were in - [ ] cmd line file decode - [ ] Waterfall direction - [ ] documentation or use, walk through, you tube, blog posts - -[ ] Web support for Presence/spotting hooks - ================= USER GUIDE NOTES ================= @@ -341,3 +236,18 @@ Currents commands: "pttoff" - PTT off (receive) Hint: "netcat" can be used to test this feature. + +4/ Full Duplex Testing with loopback +------------------------------------ + +FreeDV GUI can operate in full duplex mode which is useful for +development as only one PC is required. Tx and Rx signals can be +looped back via an analog connection between the sound cards, or (on +Linux) using the Alsa loopback module: + +$ sudo modprobe snd-aloop +$ ./freedv + +In Tools - Audio Config - Receive Tab - From Radio select -> Loopback: Loopback PCM (hw:1,0) + - Transmit Tab - To Radio select -> Loopback: Loopback PCM (hw:1,1) + -- 2.25.1