From a5979ee9c2d735656d19882b984989109476aad5 Mon Sep 17 00:00:00 2001 From: Russell Ballestrini Date: Thu, 28 May 2026 10:56:10 -0400 Subject: [PATCH] chat.html: widen MARK/SPACE swing to 0.95/0.10 for decode margin The binary carrier swung only 0.20-0.80; through a lossy codec that narrow gap shrinks the margin between MARK and SPACE. Widen to 0.95 (near full scale, no clip) and 0.10 (low but non-zero so the tone stays present for energy detection), giving the adaptive-threshold decoder a cleaner split. --- web/chat.html | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/web/chat.html b/web/chat.html index e142f3c..b3aa45c 100644 --- a/web/chat.html +++ b/web/chat.html @@ -452,8 +452,8 @@ var QRCode;(function(){function QR8bitByte(data){this.mode=QRMode.MODE_8BIT_BYTE /* ============================================================== * * constants (mirror include/zebra.h) * * ============================================================== */ -const ZEBRA_VOL_MARK = 0.80; -const ZEBRA_VOL_SPACE = 0.20; +const ZEBRA_VOL_MARK = 0.95; /* near full-scale (no clip) for max margin */ +const ZEBRA_VOL_SPACE = 0.10; /* low but non-zero so the tone stays present */ /* Link baud for the whole audio modem (handshake + data). Tunable via ?baud=N * because the WebRTC Opus path encodes in 20ms frames and smears bit edges: * lower baud = more audio quanta per symbol = survives the smear, but slower.