/* * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc. * * This file is part of PortaPack. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #include "proc_wideband_spectrum.hpp" #include "event_m4.hpp" #include "i2s.hpp" using namespace lpc43xx; #include "dsp_fft.hpp" #include #include #include /* Employ window-presum technique with a window constructed to act like a bin filter. See: http://www.embedded.com/design/real-time-and-performance/4007611/DSP-Tricks-Building-a-practical-spectrum-analyzer 20MHz / 256 bins = 78.125kHz/bin Taps made with IPython Notebook "specan_lpf", 26041.666667Hz pass, 53400Hz stop, 1024 taps, Remez, gain of 4 * 128. */ static constexpr std::array window_wideband_bin_lpf { { 0.0000000000f, -0.1215729938f, -0.1213842597f, -0.1201684429f, -0.1201208291f, -0.1190024264f, -0.1190858794f, -0.1180910084f, -0.1182902140f, -0.1173947314f, -0.1177379144f, -0.1169320615f, -0.1174165122f, -0.1166760717f, -0.1173065305f, -0.1166353753f, -0.1174295604f, -0.1168115435f, -0.1177737061f, -0.1171681501f, -0.1183154633f, -0.1176885372f, -0.1190734477f, -0.1183823726f, -0.1200564042f, -0.1191925052f, -0.1212624937f, -0.1200347844f, -0.1227782673f, -0.1205369109f, -0.1247875900f, -0.1173893915f, -0.1356269751f, -0.1333820215f, -0.1230013683f, -0.1270419996f, -0.1248521391f, -0.1280766855f, -0.1275474455f, -0.1303677621f, -0.1305094750f, -0.1330985791f, -0.1335694857f, -0.1359864220f, -0.1366453783f, -0.1389458751f, -0.1397338876f, -0.1419434716f, -0.1428068116f, -0.1449481895f, -0.1458627832f, -0.1479788256f, -0.1489403301f, -0.1510623954f, -0.1520476681f, -0.1541795914f, -0.1551676484f, -0.1573540028f, -0.1583282171f, -0.1606274956f, -0.1614806858f, -0.1640690747f, -0.1645983125f, -0.1683593655f, -0.1685811576f, -0.1666149935f, -0.1723006308f, -0.1738005522f, -0.1764397529f, -0.1778294249f, -0.1798377067f, -0.1812660021f, -0.1831168886f, -0.1846305866f, -0.1864679413f, -0.1881030278f, -0.1899836720f, -0.1917311189f, -0.1936526632f, -0.1954904285f, -0.1974621775f, -0.1993785604f, -0.2013983100f, -0.2033652690f, -0.2054038199f, -0.2073919547f, -0.2094317510f, -0.2114475228f, -0.2134958020f, -0.2155244502f, -0.2175598198f, -0.2195723764f, -0.2216212397f, -0.2236245172f, -0.2256330226f, -0.2276718013f, -0.2285011851f, -0.2330266272f, -0.2341760732f, -0.2355468158f, -0.2372897729f, -0.2390892017f, -0.2410984360f, -0.2430630996f, 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-0.3148580017f, -0.3146624743f, -0.3145480407f, -0.3143048413f, -0.3140959719f, -0.3137462882f, -0.3133944699f, -0.3129048624f, -0.3123958369f, -0.3117751598f, -0.3111336729f, -0.3103913733f, -0.3096257208f, -0.3087558210f, -0.3078644089f, -0.3068771119f, -0.3058756301f, -0.3047953307f, -0.3036791840f, -0.3024750370f, -0.3012206975f, -0.2998832522f, -0.2985327732f, -0.2970457316f, -0.2955408715f, -0.2939578995f, -0.2921271926f, -0.2909536921f, -0.2886979015f, -0.2867034021f, -0.2848865889f, -0.2829509809f, -0.2809996598f, -0.2788599641f, -0.2766682382f, -0.2743418063f, -0.2719823809f, -0.2695102609f, -0.2670290887f, -0.2644425265f, -0.2618581518f, -0.2591571117f, -0.2564433319f, -0.2536057399f, -0.2507463340f, -0.2477656128f, -0.2447669078f, -0.2416375134f, -0.2384901545f, -0.2351846242f, -0.2318685842f, -0.2284043787f, -0.2249483716f, -0.2213504338f, -0.2177326536f, -0.2139529315f, -0.2102567274f, -0.2062425510f, -0.2025752799f, -0.1982312400f, -0.1941135048f, -0.1902676621f, 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1.9281575220f, 1.9231368617f, 1.9179684698f, 1.9127216689f, 1.9073312666f, 1.9018629597f, 1.8962629246f, 1.8906028239f, 1.8848148272f, 1.8789794347f, 1.8730100097f, 1.8669819454f, 1.8608040839f, 1.8545405038f, 1.8481458306f, 1.8417084040f, 1.8351580541f, 1.8285934275f, 1.8217244084f, 1.8149423807f, 1.8080175914f, 1.8009680396f, 1.7939083209f, 1.7866595518f, 1.7793864240f, 1.7720587141f, 1.7645736334f, 1.7570307435f, 1.7493721167f, 1.7416709937f, 1.7338708023f, 1.7260006052f, 1.7180180271f, 1.7099724793f, 1.7018206388f, 1.6936257655f, 1.6853322111f, 1.6769969948f, 1.6685645243f, 1.6600728279f, 1.6514803963f, 1.6428196478f, 1.6340558312f, 1.6252361387f, 1.6163275268f, 1.6073964215f, 1.5983995178f, 1.5893352932f, 1.5801889794f, 1.5708923706f, 1.5616442576f, 1.5523880267f, 1.5428771970f, 1.5335015901f, 1.5238981621f, 1.5143471956f, 1.5047009642f, 1.4949664411f, 1.4851755647f, 1.4753745521f, 1.4654880955f, 1.4555829383f, 1.4455694200f, 1.4355455123f, 1.4254416597f, 1.4153304829f, 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channel_filter_pass_frequency = 0; channel_filter_stop_frequency = 0; channel_spectrum_request_update = true; events_flag(EVT_MASK_SPECTRUM); phase = 0; } } else { phase++; } i2s::i2s0::tx_mute(); }