/* Copyright 2023 OneOfEleven * https://github.com/DualTachyon * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ // code to 'try' and reduce the AM demodulator saturation problem // // that is until someone works out how to properly configure the BK chip ! #include #include "am_fix.h" #include "app/main.h" #include "board.h" #include "driver/bk4819.h" #include "external/printf/printf.h" #include "frequencies.h" #include "functions.h" #include "misc.h" #include "ui/rssi.h" // original QS front end register settings const uint8_t orig_lna_short = 3; // 0dB const uint8_t orig_lna = 2; // -14dB const uint8_t orig_mixer = 3; // 0dB const uint8_t orig_pga = 6; // -3dB #ifdef ENABLE_AM_FIX typedef struct { #if 1 // bitfields take up less flash bytes uint8_t lna_short:2; // 0 ~ 3 uint8_t lna:3; // 0 ~ 7 uint8_t mixer:2; // 0 ~ 3 uint8_t pga:3; // 0 ~ 7 #else uint8_t lna_short; // 0 ~ 3 uint8_t lna; // 0 ~ 7 uint8_t mixer; // 0 ~ 3 uint8_t pga; // 0 ~ 7 #endif } t_am_fix_gain_table; //} __attribute__((packed)) t_am_fix_gain_table; // REG_10 AGC gain table // // <15:10> ??? // // <9:8> = LNA Gain Short // 3 = 0dB < original value // 2 = -24dB // was -11 // 1 = -30dB // was -16 // 0 = -33dB // was -19 // // <7:5> = LNA Gain // 7 = 0dB // 6 = -2dB // 5 = -4dB // 4 = -6dB // 3 = -9dB // 2 = -14dB < original value // 1 = -19dB // 0 = -24dB // // <4:3> = MIXER Gain // 3 = 0dB < original value // 2 = -3dB // 1 = -6dB // 0 = -8dB // // <2:0> = PGA Gain // 7 = 0dB // 6 = -3dB < original value // 5 = -6dB // 4 = -9dB // 3 = -15dB // 2 = -21dB // 1 = -27dB // 0 = -33dB // front end register dB values - needs a measuring/calibration update really // static const int16_t lna_short_dB[] = {-19, -16, -11, 0}; // was static const int16_t lna_short_dB[] = {-33, -30 -24, 0}; // corrected'ish static const int16_t lna_dB[] = {-24, -19, -14, -9, -6, -4, -2, 0}; static const int16_t mixer_dB[] = { -8, -6, -3, 0}; static const int16_t pga_dB[] = {-33, -27, -21, -15, -9, -6, -3, 0}; // lookup table is by far easier than writing code to do the same // static const t_am_fix_gain_table am_fix_gain_table[] = { {.lna_short = 3, .lna = 2, .mixer = 3, .pga = 6}, // 0 0dB -14dB 0dB -3dB .. -17dB original #ifdef ENABLE_AM_FIX_TEST1 // test table that lets me manually set the lna-short register // to measure it's actual dB change using an RF signal generator {0, 2, 3, 6}, // 1 -33dB -14dB 0dB -3dB .. -50dB {1, 2, 3, 6}, // 2 -30dB -14dB 0dB -3dB .. -47dB {2, 2, 3, 6}, // 3 -24dB -14dB 0dB -3dB .. -41dB {3, 2, 3, 6} // 4 0dB -14dB 0dB -3dB .. -17dB const unsigned int original_index = 1; #elif 0 // in this table the 'lna-short' register I leave unchanged {3, 0, 0, 0}, // 1 0dB -24dB -8dB -33dB .. -65dB {3, 0, 1, 0}, // 2 0dB -24dB -6dB -33dB .. -63dB {3, 0, 2, 0}, // 3 0dB -24dB -3dB -33dB .. -60dB {3, 0, 0, 1}, // 4 0dB -24dB -8dB -27dB .. -59dB {3, 1, 1, 0}, // 5 0dB -19dB -6dB -33dB .. -58dB {3, 0, 1, 1}, // 6 0dB -24dB -6dB -27dB .. -57dB {3, 1, 2, 0}, // 7 0dB -19dB -3dB -33dB .. -55dB {3, 1, 0, 1}, // 8 0dB -19dB -8dB -27dB .. -54dB {3, 0, 0, 2}, // 9 0dB -24dB -8dB -21dB .. -53dB {3, 1, 1, 1}, // 10 0dB -19dB -6dB -27dB .. -52dB {3, 0, 1, 2}, // 11 0dB -24dB -6dB -21dB .. -51dB {3, 2, 2, 0}, // 12 0dB -14dB -3dB -33dB .. -50dB {3, 2, 0, 1}, // 13 0dB -14dB -8dB -27dB .. -49dB {3, 0, 2, 2}, // 14 0dB -24dB -3dB -21dB .. -48dB {3, 2, 3, 0}, // 15 0dB -14dB 0dB -33dB .. -47dB {3, 1, 3, 1}, // 16 0dB -19dB 0dB -27dB .. -46dB {3, 0, 3, 2}, // 17 0dB -24dB 0dB -21dB .. -45dB {3, 3, 0, 1}, // 18 0dB -9dB -8dB -27dB .. -44dB {3, 1, 2, 2}, // 19 0dB -19dB -3dB -21dB .. -43dB {3, 0, 2, 3}, // 20 0dB -24dB -3dB -15dB .. -42dB {3, 0, 0, 4}, // 21 0dB -24dB -8dB -9dB .. -41dB {3, 1, 1, 3}, // 22 0dB -19dB -6dB -15dB .. -40dB {3, 0, 1, 4}, // 23 0dB -24dB -6dB -9dB .. -39dB {3, 0, 0, 5}, // 24 0dB -24dB -8dB -6dB .. -38dB {3, 1, 2, 3}, // 25 0dB -19dB -3dB -15dB .. -37dB {3, 0, 2, 4}, // 26 0dB -24dB -3dB -9dB .. -36dB {3, 4, 0, 2}, // 27 0dB -6dB -8dB -21dB .. -35dB {3, 1, 1, 4}, // 28 0dB -19dB -6dB -9dB .. -34dB {3, 1, 0, 5}, // 29 0dB -19dB -8dB -6dB .. -33dB {3, 3, 0, 3}, // 30 0dB -9dB -8dB -15dB .. -32dB {3, 5, 1, 2}, // 31 0dB -4dB -6dB -21dB .. -31dB {3, 1, 0, 6}, // 32 0dB -19dB -8dB -3dB .. -30dB {3, 2, 3, 3}, // 33 0dB -14dB 0dB -15dB .. -29dB {3, 1, 1, 6}, // 34 0dB -19dB -6dB -3dB .. -28dB {3, 4, 1, 3}, // 35 0dB -6dB -6dB -15dB .. -27dB {3, 2, 2, 4}, // 36 0dB -14dB -3dB -9dB .. -26dB {3, 1, 2, 6}, // 37 0dB -19dB -3dB -3dB .. -25dB {3, 3, 1, 4}, // 38 0dB -9dB -6dB -9dB .. -24dB {3, 2, 1, 6}, // 39 0dB -14dB -6dB -3dB .. -23dB {3, 5, 2, 3}, // 40 0dB -4dB -3dB -15dB .. -22dB {3, 4, 1, 4}, // 41 0dB -6dB -6dB -9dB .. -21dB {3, 4, 0, 5}, // 42 0dB -6dB -8dB -6dB .. -20dB {3, 5, 1, 4}, // 43 0dB -4dB -6dB -9dB .. -19dB {3, 3, 3, 4}, // 44 0dB -9dB 0dB -9dB .. -18dB {3, 2, 3, 6}, // 45 0dB -14dB 0dB -3dB .. -17dB original {3, 5, 1, 5}, // 46 0dB -4dB -6dB -6dB .. -16dB {3, 3, 1, 7}, // 47 0dB -9dB -6dB 0dB .. -15dB {3, 2, 3, 7}, // 48 0dB -14dB 0dB 0dB .. -14dB {3, 5, 1, 6}, // 49 0dB -4dB -6dB -3dB .. -13dB {3, 4, 2, 6}, // 50 0dB -6dB -3dB -3dB .. -12dB {3, 5, 2, 6}, // 51 0dB -4dB -3dB -3dB .. -10dB {3, 4, 3, 6}, // 52 0dB -6dB 0dB -3dB .. -9dB {3, 5, 2, 7}, // 53 0dB -4dB -3dB 0dB .. -7dB {3, 4, 3, 7}, // 54 0dB -6dB 0dB 0dB .. -6dB {3, 5, 3, 7} // 55 0dB -4dB 0dB 0dB .. -4dB }; const unsigned int original_index = 45; #else // in this table I include adjusting the 'lna-short' register ~ // more gain adjustment range from doing so {0, 0, 0, 0}, // 1 -33dB -24dB -8dB -33dB .. -98dB {0, 0, 1, 0}, // 2 -33dB -24dB -6dB -33dB .. -96dB {1, 0, 0, 0}, // 3 -30dB -24dB -8dB -33dB .. -95dB {0, 1, 0, 0}, // 4 -33dB -19dB -8dB -33dB .. -93dB {0, 0, 0, 1}, // 5 -33dB -24dB -8dB -27dB .. -92dB {0, 1, 1, 0}, // 6 -33dB -19dB -6dB -33dB .. -91dB {0, 0, 1, 1}, // 7 -33dB -24dB -6dB -27dB .. -90dB {1, 0, 0, 1}, // 8 -30dB -24dB -8dB -27dB .. -89dB {0, 1, 2, 0}, // 9 -33dB -19dB -3dB -33dB .. -88dB {1, 0, 3, 0}, // 10 -30dB -24dB 0dB -33dB .. -87dB {0, 0, 0, 2}, // 11 -33dB -24dB -8dB -21dB .. -86dB {1, 1, 2, 0}, // 12 -30dB -19dB -3dB -33dB .. -85dB {0, 0, 3, 1}, // 13 -33dB -24dB 0dB -27dB .. -84dB {0, 3, 0, 0}, // 14 -33dB -9dB -8dB -33dB .. -83dB {1, 1, 3, 0}, // 15 -30dB -19dB 0dB -33dB .. -82dB {1, 0, 3, 1}, // 16 -30dB -24dB 0dB -27dB .. -81dB {0, 2, 3, 0}, // 17 -33dB -14dB 0dB -33dB .. -80dB {1, 2, 0, 1}, // 18 -30dB -14dB -8dB -27dB .. -79dB {0, 3, 2, 0}, // 19 -33dB -9dB -3dB -33dB .. -78dB {1, 4, 0, 0}, // 20 -30dB -6dB -8dB -33dB .. -77dB {0, 2, 0, 2}, // 21 -33dB -14dB -8dB -21dB .. -76dB {0, 3, 3, 0}, // 22 -33dB -9dB 0dB -33dB .. -75dB {1, 3, 0, 1}, // 23 -30dB -9dB -8dB -27dB .. -74dB {1, 2, 0, 2}, // 24 -30dB -14dB -8dB -21dB .. -73dB {1, 1, 0, 3}, // 25 -30dB -19dB -8dB -15dB .. -72dB {1, 4, 0, 1}, // 26 -30dB -6dB -8dB -27dB .. -71dB {1, 5, 2, 0}, // 27 -30dB -4dB -3dB -33dB .. -70dB {1, 4, 1, 1}, // 28 -30dB -6dB -6dB -27dB .. -69dB {2, 2, 2, 1}, // 29 -24dB -14dB -3dB -27dB .. -68dB {2, 1, 2, 2}, // 30 -24dB -19dB -3dB -21dB .. -67dB {2, 0, 2, 3}, // 31 -24dB -24dB -3dB -15dB .. -66dB {1, 0, 0, 6}, // 32 -30dB -24dB -8dB -3dB .. -65dB {2, 1, 1, 3}, // 33 -24dB -19dB -6dB -15dB .. -64dB {0, 3, 1, 3}, // 34 -33dB -9dB -6dB -15dB .. -63dB {2, 3, 0, 2}, // 35 -24dB -9dB -8dB -21dB .. -62dB {2, 1, 2, 3}, // 36 -24dB -19dB -3dB -15dB .. -61dB {2, 3, 1, 2}, // 37 -24dB -9dB -6dB -21dB .. -60dB {2, 2, 3, 2}, // 38 -24dB -14dB 0dB -21dB .. -59dB {2, 1, 1, 4}, // 39 -24dB -19dB -6dB -9dB .. -58dB {2, 4, 1, 2}, // 40 -24dB -6dB -6dB -21dB .. -57dB {1, 2, 2, 4}, // 41 -30dB -14dB -3dB -9dB .. -56dB {2, 1, 1, 5}, // 42 -24dB -19dB -6dB -6dB .. -55dB {2, 3, 3, 2}, // 43 -24dB -9dB 0dB -21dB .. -54dB {1, 3, 0, 5}, // 44 -30dB -9dB -8dB -6dB .. -53dB {1, 5, 2, 3}, // 45 -30dB -4dB -3dB -15dB .. -52dB {1, 3, 1, 5}, // 46 -30dB -9dB -6dB -6dB .. -51dB {0, 2, 2, 7}, // 47 -33dB -14dB -3dB 0dB .. -50dB {2, 1, 1, 7}, // 48 -24dB -19dB -6dB 0dB .. -49dB {0, 4, 2, 5}, // 49 -33dB -6dB -3dB -6dB .. -48dB {1, 2, 3, 6}, // 50 -30dB -14dB 0dB -3dB .. -47dB {1, 5, 1, 5}, // 51 -30dB -4dB -6dB -6dB .. -46dB {3, 0, 3, 2}, // 52 0dB -24dB 0dB -21dB .. -45dB {3, 2, 2, 1}, // 53 0dB -14dB -3dB -27dB .. -44dB {2, 5, 1, 4}, // 54 -24dB -4dB -6dB -9dB .. -43dB {1, 4, 2, 6}, // 55 -30dB -6dB -3dB -3dB .. -42dB {3, 0, 0, 4}, // 56 0dB -24dB -8dB -9dB .. -41dB {0, 5, 3, 6}, // 57 -33dB -4dB 0dB -3dB .. -40dB {2, 4, 2, 5}, // 58 -24dB -6dB -3dB -6dB .. -39dB {3, 0, 0, 5}, // 59 0dB -24dB -8dB -6dB .. -38dB {0, 5, 3, 7}, // 60 -33dB -4dB 0dB 0dB .. -37dB {2, 3, 3, 6}, // 61 -24dB -9dB 0dB -3dB .. -36dB {3, 4, 0, 2}, // 62 0dB -6dB -8dB -21dB .. -35dB {3, 1, 1, 4}, // 63 0dB -19dB -6dB -9dB .. -34dB {3, 0, 3, 4}, // 64 0dB -24dB 0dB -9dB .. -33dB {3, 3, 0, 3}, // 65 0dB -9dB -8dB -15dB .. -32dB {3, 1, 1, 5}, // 66 0dB -19dB -6dB -6dB .. -31dB {3, 0, 2, 6}, // 67 0dB -24dB -3dB -3dB .. -30dB {3, 2, 3, 3}, // 68 0dB -14dB 0dB -15dB .. -29dB {3, 2, 0, 5}, // 69 0dB -14dB -8dB -6dB .. -28dB {3, 4, 1, 3}, // 70 0dB -6dB -6dB -15dB .. -27dB {3, 2, 2, 4}, // 71 0dB -14dB -3dB -9dB .. -26dB {3, 1, 2, 6}, // 72 0dB -19dB -3dB -3dB .. -25dB {3, 3, 1, 4}, // 73 0dB -9dB -6dB -9dB .. -24dB {3, 2, 1, 6}, // 74 0dB -14dB -6dB -3dB .. -23dB {3, 5, 2, 3}, // 75 0dB -4dB -3dB -15dB .. -22dB {3, 4, 1, 4}, // 76 0dB -6dB -6dB -9dB .. -21dB {3, 4, 0, 5}, // 77 0dB -6dB -8dB -6dB .. -20dB {3, 5, 1, 4}, // 78 0dB -4dB -6dB -9dB .. -19dB {3, 3, 3, 4}, // 79 0dB -9dB 0dB -9dB .. -18dB {3, 2, 3, 6}, // 80 0dB -14dB 0dB -3dB .. -17dB original {3, 5, 1, 5}, // 81 0dB -4dB -6dB -6dB .. -16dB {3, 3, 1, 7}, // 82 0dB -9dB -6dB 0dB .. -15dB {3, 2, 3, 7}, // 83 0dB -14dB 0dB 0dB .. -14dB {3, 5, 1, 6}, // 84 0dB -4dB -6dB -3dB .. -13dB {3, 4, 2, 6}, // 85 0dB -6dB -3dB -3dB .. -12dB {3, 5, 2, 6}, // 86 0dB -4dB -3dB -3dB .. -10dB {3, 4, 3, 6}, // 87 0dB -6dB 0dB -3dB .. -9dB {3, 5, 2, 7}, // 88 0dB -4dB -3dB 0dB .. -7dB {3, 4, 3, 7}, // 89 0dB -6dB 0dB 0dB .. -6dB {3, 5, 3, 7} // 90 0dB -4dB 0dB 0dB .. -4dB }; const unsigned int original_index = 80; #endif // current table index we're using #ifdef ENABLE_AM_FIX_TEST1 unsigned int am_fix_gain_table_index = 1; #else unsigned int am_fix_gain_table_index = original_index; // start with original QS setting #endif unsigned int am_fix_gain_table_index_prev = 0; // moving average RSSI buffer // helps smooth out any spikey RSSI readings struct { unsigned int count; // unsigned int index; // read/write buffer index uint16_t samples[4]; // 40ms long buffer (10ms RSSI sample rate) uint16_t sum; // sum of all samples in the buffer } moving_avg_rssi = {0}; // used to prevent gain hunting, provides a peak hold time delay unsigned int am_gain_hold_counter = 0; // used to correct the RSSI readings after our front end gain adjustments int16_t rssi_db_gain_diff = 0; void AM_fix_reset(void) { // reset the moving average filter memset(&moving_avg_rssi, 0, sizeof(moving_avg_rssi)); am_gain_hold_counter = 0; rssi_db_gain_diff = 0; #ifdef ENABLE_AM_FIX_TEST1 am_fix_gain_table_index = 1 + gSetting_AM_fix_test1; #else am_fix_gain_table_index = original_index; // re-start with original QS setting #endif am_fix_gain_table_index_prev = 0; } void AM_fix_adjust_frontEnd_10ms(void) { #ifndef ENABLE_AM_FIX_TEST1 // -89dBm, any higher and the AM demodulator starts to saturate/clip/distort const uint16_t desired_rssi = (-89 + 160) * 2; // dBm to ADC sample #endif // we don't play with the front end gains if in FM mode // they remain as per QS original if (!gRxVfo->IsAM) return; // we're in AM mode switch (gCurrentFunction) { case FUNCTION_TRANSMIT: case FUNCTION_BAND_SCOPE: case FUNCTION_POWER_SAVE: case FUNCTION_FOREGROUND: return; // only adjust the front end if in one of these modes case FUNCTION_RECEIVE: case FUNCTION_MONITOR: case FUNCTION_INCOMING: break; } // sample the current RSSI level uint16_t rssi = BK4819_GetRSSI(); // supposed 9-bit value (0 .. 511) - never seen that though #if 1 // compute a moving average RSSI - just smooths any sharp spikes if (moving_avg_rssi.count < ARRAY_SIZE(moving_avg_rssi.samples)) moving_avg_rssi.count++; moving_avg_rssi.sum -= moving_avg_rssi.samples[moving_avg_rssi.index]; // subtract the oldest sample moving_avg_rssi.sum += rssi; // add the newest sample moving_avg_rssi.samples[moving_avg_rssi.index] = rssi; // save the newest sample if (++moving_avg_rssi.index >= ARRAY_SIZE(moving_avg_rssi.samples)) // moving_avg_rssi.index = 0; // rssi = moving_avg_rssi.sum / moving_avg_rssi.count; // compute the average of the past 'n' samples #endif //gCurrentRSSI[gEeprom.RX_CHANNEL] = rssi - (rssi_db_gain_diff * 2); #ifdef ENABLE_AM_FIX_TEST1 am_fix_gain_table_index = 1 + gSetting_AM_fix_test1; if (am_gain_hold_counter > 0) if (--am_gain_hold_counter > 0) return; am_gain_hold_counter = 250; // 250ms #else if (rssi > desired_rssi) { // decrease gain if (am_fix_gain_table_index > 1) am_fix_gain_table_index--; am_gain_hold_counter = 50; // 500ms } if (am_gain_hold_counter > 0) am_gain_hold_counter--; if (am_gain_hold_counter == 0) { // hold has been released, we're now free to increase gain if (rssi < (desired_rssi - 10)) // 5dB hysterisis (helps reduce gain hunting) { // increase gain if (am_fix_gain_table_index < (ARRAY_SIZE(am_fix_gain_table) - 1)) am_fix_gain_table_index++; } } if (am_fix_gain_table_index == am_fix_gain_table_index_prev) return; // no gain changes have been made #endif // apply the new settings to the front end registers const uint16_t lna_short = am_fix_gain_table[am_fix_gain_table_index].lna_short; const uint16_t lna = am_fix_gain_table[am_fix_gain_table_index].lna; const uint16_t mixer = am_fix_gain_table[am_fix_gain_table_index].mixer; const uint16_t pga = am_fix_gain_table[am_fix_gain_table_index].pga; BK4819_WriteRegister(BK4819_REG_13, (lna_short << 8) | (lna << 5) | (mixer << 3) | (pga << 0)); { // offset the RSSI reading to the rest of the firmware to cancel out the gain adjustments we've made here const int16_t orig_dB_gain = lna_short_dB[orig_lna_short] + lna_dB[orig_lna] + mixer_dB[orig_mixer] + pga_dB[orig_pga]; const int16_t am_dB_gain = lna_short_dB[lna_short] + lna_dB[lna] + mixer_dB[mixer] + pga_dB[pga]; rssi_db_gain_diff = am_dB_gain - orig_dB_gain; //gCurrentRSSI[gEeprom.RX_CHANNEL] = rssi - (rssi_db_gain_diff * 2); } // remember the new table index am_fix_gain_table_index_prev = am_fix_gain_table_index; #ifdef ENABLE_AM_FIX_SHOW_DATA gUpdateDisplay = true; #endif } #ifdef ENABLE_AM_FIX_SHOW_DATA void AM_fix_print_data(char *s) { if (s == NULL) return; // fetch current register settings const uint16_t lna_short = am_fix_gain_table[am_fix_gain_table_index].lna_short; const uint16_t lna = am_fix_gain_table[am_fix_gain_table_index].lna; const uint16_t mixer = am_fix_gain_table[am_fix_gain_table_index].mixer; const uint16_t pga = am_fix_gain_table[am_fix_gain_table_index].pga; // compute the current front end gain const int16_t dB_gain = lna_short_dB[lna_short] + lna_dB[lna] + mixer_dB[mixer] + pga_dB[pga]; sprintf(s, "idx %2d %4ddB %3u", am_fix_gain_table_index, dB_gain, BK4819_GetRSSI()); } #endif #endif