-
Notifications
You must be signed in to change notification settings - Fork 437
/
am_fix.c
397 lines (344 loc) · 12.7 KB
/
am_fix.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
/* 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 <string.h>
#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 "settings.h"
#ifdef ENABLE_AGC_SHOW_DATA
#include "ui/main.h"
#endif
#ifdef ENABLE_AM_FIX
typedef struct
{
uint16_t reg_val;
int8_t gain_dB;
} __attribute__((packed)) t_gain_table;
// REG_10 AGC gain table
//
// <15:10> ???
//
// <9:8> = LNA Gain Short
// 3 = 0dB < original value
// 2 = -19dB // was -11
// 1 = -24dB // was -16
// 0 = -28dB // was -19
//
// <7:5> = LNA Gain
// 7 = 0dB
// 6 = -2dB
// 5 = -4dB < original value
// 4 = -6dB
// 3 = -9dB
// 2 = -14dB
// 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
//
// these values need to be accurate for the code to properly/reliably switch
// between table entries when adjusting the front end registers.
//
// these 4 tables need a measuring/calibration update
//
//// static const int16_t lna_short_dB[] = { -19, -16, -11, 0}; // was (but wrong)
// static const int16_t lna_short_dB[] = { (-28), (-24), (-19), 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 hugely easier than writing code to do the same
//
#define LOOKUP_TABLE 1
#if LOOKUP_TABLE
static const t_gain_table gain_table[] =
{
{0x03BE, -7}, // 0 .. 3 5 3 6 .. 0dB -4dB 0dB -3dB .. -7dB original
{0x0000,-93}, // 1 .. 0 0 0 0 .. -28dB -24dB -8dB -33dB .. -93dB
{0x0008,-91}, // 2 .. 0 0 1 0 .. -28dB -24dB -6dB -33dB .. -91dB
{0x0010,-88}, // 3 .. 0 0 2 0 .. -28dB -24dB -3dB -33dB .. -88dB
{0x0001,-87}, // 4 .. 0 0 0 1 .. -28dB -24dB -8dB -27dB .. -87dB
{0x0009,-85}, // 5 .. 0 0 1 1 .. -28dB -24dB -6dB -27dB .. -85dB
{0x0011,-82}, // 6 .. 0 0 2 1 .. -28dB -24dB -3dB -27dB .. -82dB
{0x0002,-81}, // 7 .. 0 0 0 2 .. -28dB -24dB -8dB -21dB .. -81dB
{0x000A,-79}, // 8 .. 0 0 1 2 .. -28dB -24dB -6dB -21dB .. -79dB
{0x0012,-76}, // 9 .. 0 0 2 2 .. -28dB -24dB -3dB -21dB .. -76dB
{0x0003,-75}, // 10 .. 0 0 0 3 .. -28dB -24dB -8dB -15dB .. -75dB
{0x000B,-73}, // 11 .. 0 0 1 3 .. -28dB -24dB -6dB -15dB .. -73dB
{0x0013,-70}, // 12 .. 0 0 2 3 .. -28dB -24dB -3dB -15dB .. -70dB
{0x0004,-69}, // 13 .. 0 0 0 4 .. -28dB -24dB -8dB -9dB .. -69dB
{0x000C,-67}, // 14 .. 0 0 1 4 .. -28dB -24dB -6dB -9dB .. -67dB
{0x000D,-64}, // 15 .. 0 0 1 5 .. -28dB -24dB -6dB -6dB .. -64dB
{0x001C,-61}, // 16 .. 0 0 3 4 .. -28dB -24dB 0dB - 9dB .. -61dB
{0x001D,-58}, // 17 .. 0 0 3 5 .. -28dB -24dB 0dB -6dB .. -58dB
{0x001E,-55}, // 18 .. 0 0 3 6 .. -28dB -24dB 0dB -3dB .. -55dB
{0x001F,-52}, // 19 .. 0 0 3 7 .. -28dB -24dB 0dB 0dB .. -52dB
{0x003E,-50}, // 20 .. 0 1 3 6 .. -28dB -19dB 0dB -3dB .. -50dB
{0x003F,-47}, // 21 .. 0 1 3 7 .. -28dB -19dB 0dB 0dB .. -47dB
{0x005E,-45}, // 22 .. 0 2 3 6 .. -28dB -14dB 0dB -3dB .. -45dB
{0x005F,-42}, // 23 .. 0 2 3 7 .. -28dB -14dB 0dB 0dB .. -42dB
{0x007E,-40}, // 24 .. 0 3 3 6 .. -28dB -9dB 0dB -3dB .. -40dB
{0x007F,-37}, // 25 .. 0 3 3 7 .. -28dB -9dB 0dB 0dB .. -37dB
{0x009F,-34}, // 26 .. 0 4 3 7 .. -28dB -6dB 0dB 0dB .. -34dB
{0x00BF,-32}, // 27 .. 0 5 3 7 .. -28dB -4dB 0dB 0dB .. -32dB
{0x00DF,-30}, // 28 .. 0 6 3 7 .. -28dB -2dB 0dB 0dB .. -30dB
{0x00FF,-28}, // 29 .. 0 7 3 7 .. -28dB 0dB 0dB 0dB .. -28dB
{0x01DF,-26}, // 30 .. 1 6 3 7 .. -24dB -2dB 0dB 0dB .. -26dB
{0x01FF,-24}, // 31 .. 1 7 3 7 .. -24dB 0dB 0dB 0dB .. -24dB
{0x02BF,-23}, // 32 .. 2 5 3 7 .. -19dB -4dB 0dB 0dB .. -23dB
{0x02DF,-21}, // 33 .. 2 6 3 7 .. -19dB -2dB 0dB -0dB .. -21dB
{0x02FF,-19}, // 34 .. 2 7 3 7 .. -19dB 0dB 0dB 0dB .. -19dB
{0x035E,-17}, // 35 .. 3 2 3 6 .. 0dB -14dB 0dB -3dB .. -17dB
{0x035F,-14}, // 36 .. 3 2 3 7 .. 0dB -14dB 0dB 0dB .. -14dB
{0x037E,-12}, // 37 .. 3 3 3 6 .. 0dB -9dB 0dB -3dB .. -12dB
{0x037F,-9}, // 38 .. 3 3 3 7 .. 0dB -9dB 0dB 0dB .. -9dB
{0x038F,-6}, // 39 .. 3 4 3 7 .. 0dB - 6dB 0dB 0dB .. -6dB
{0x03BF,-4}, // 40 .. 3 5 3 7 .. 0dB -4dB 0dB 0dB .. -4dB
{0x03DF,-2}, // 41 .. 3 6 3 7 .. 0dB - 2dB 0dB 0dB .. -2dB
{0x03FF,0} // 42 .. 3 7 3 7 .. 0dB 0dB 0dB 0dB .. 0dB
};
const uint8_t gain_table_size = ARRAY_SIZE(gain_table);
#else
t_gain_table gain_table[100] = {{0x03BE, -7}}; //original
uint8_t gain_table_size = 0;
void CreateTable()
{
typedef union {
struct {
uint8_t pgaIdx:3;
uint8_t mixerIdx:2;
uint8_t lnaIdx:3;
uint8_t lnaSIdx:2;
};
uint16_t __raw;
} GainData;
static const int8_t lna_short_dB[] = {-28, -24, -19, 0}; // corrected'ish
static const int8_t lna_dB[] = {-24, -19, -14, -9, -6, -4, -2, 0};
static const int8_t mixer_dB[] = { -8, -6, -3, 0};
static const int8_t pga_dB[] = {-33, -27, -21, -15, -9, -6, -3, 0};
unsigned i;
for (uint8_t lnaSIdx = 0; lnaSIdx < ARRAY_SIZE(lna_short_dB); lnaSIdx++) {
for (uint8_t lnaIdx = 0; lnaIdx < ARRAY_SIZE(lna_dB); lnaIdx++) {
for (uint8_t mixerIdx = 0; mixerIdx < ARRAY_SIZE(mixer_dB); mixerIdx++) {
for (uint8_t pgaIdx = 0; pgaIdx < ARRAY_SIZE(pga_dB); pgaIdx++) {
int16_t db = lna_short_dB[lnaSIdx] + lna_dB[lnaIdx] + mixer_dB[mixerIdx] + pga_dB[pgaIdx];
GainData gainData = {{
pgaIdx,
mixerIdx,
lnaIdx,
lnaSIdx,
}};
for (i = 1; i < ARRAY_SIZE(gain_table); i++) {
t_gain_table * gain = &gain_table[i];
if (db == gain->gain_dB)
break;
if (db > gain->gain_dB)
continue;
if (db < gain->gain_dB) {
if(gain->gain_dB)
memmove(gain + 1, gain, 100 - i);
gain->gain_dB = db;
gain->reg_val = gainData.__raw;
break;
}
gain->gain_dB = db;
gain->reg_val = gainData.__raw;
break;
}
}
}
}
}
gain_table_size = i+1;
}
#endif
#ifdef ENABLE_AM_FIX_SHOW_DATA
// display update rate
static const unsigned int display_update_rate = 250 / 10; // max 250ms display update rate
unsigned int counter = 0;
#endif
unsigned int gain_table_index[2] = {0, 0};
// used simply to detect a changed gain setting
unsigned int gain_table_index_prev[2] = {0, 0};
// holds the previous RSSI level .. we do an average of old + new RSSI reading
int16_t prev_rssi[2] = {0, 0};
// to help reduce gain hunting, peak hold count down tick
unsigned int hold_counter[2] = {0, 0};
// -89dBm, any higher and the AM demodulator starts to saturate/clip/distort
const int16_t desired_rssi = (-89 + 160) * 2;
int8_t currentGainDiff;
bool enabled = true;
void AM_fix_init(void)
{ // called at boot-up
for (int i = 0; i < 2; i++) {
gain_table_index[i] = 0; // re-start with original QS setting
}
#if !LOOKUP_TABLE
CreateTable();
#endif
}
void AM_fix_reset(const unsigned vfo)
{ // reset the AM fixer upper
if (vfo > 1)
return;
#ifdef ENABLE_AM_FIX_SHOW_DATA
counter = 0;
#endif
prev_rssi[vfo] = 0;
hold_counter[vfo] = 0;
gain_table_index_prev[vfo] = 0;
}
// adjust the RX gain to try and prevent the AM demodulator from
// saturating/overloading/clipping (distorted AM audio)
//
// we're actually doing the BK4819's job for it here, but as the chip
// won't/don't do it for itself, we're left to bodging it ourself by
// playing with the RF front end gain setting
//
void AM_fix_10ms(const unsigned vfo)
{
if(!gSetting_AM_fix || !enabled || vfo > 1 )
return;
if (gCurrentFunction != FUNCTION_FOREGROUND && !FUNCTION_IsRx()) {
#ifdef ENABLE_AM_FIX_SHOW_DATA
counter = display_update_rate; // queue up a display update as soon as we switch to RX mode
#endif
return;
}
#ifdef ENABLE_AM_FIX_SHOW_DATA
if (counter > 0) {
if (++counter >= display_update_rate) { // trigger a display update
counter = 0;
gUpdateDisplay = true;
}
}
#endif
static uint32_t lastFreq[2];
if(gEeprom.VfoInfo[vfo].pRX->Frequency != lastFreq[vfo]) {
lastFreq[vfo] = gEeprom.VfoInfo[vfo].pRX->Frequency;
AM_fix_reset(vfo);
}
int16_t rssi;
{ // sample the current RSSI level
// average it with the previous rssi (a bit of noise/spike immunity)
const int16_t new_rssi = BK4819_GetRSSI();
rssi = (prev_rssi[vfo] > 0) ? (prev_rssi[vfo] + new_rssi) / 2 : new_rssi;
prev_rssi[vfo] = new_rssi;
}
#ifdef ENABLE_AM_FIX_SHOW_DATA
{
static int16_t lastRssi;
if (lastRssi != rssi) { // rssi changed
lastRssi = rssi;
if (counter == 0) {
counter = 1;
gUpdateDisplay = true; // trigger a display update
}
}
}
#endif
// automatically adjust the RF RX gain
// update the gain hold counter
if (hold_counter[vfo] > 0)
hold_counter[vfo]--;
// dB difference between actual and desired RSSI level
int16_t diff_dB = (rssi - desired_rssi) / 2;
if (diff_dB > 0) { // decrease gain
unsigned int index = gain_table_index[vfo]; // current position we're at
if (diff_dB >= 10) { // jump immediately to a new gain setting
// this greatly speeds up initial gain reduction (but reduces noise/spike immunity)
const int16_t desired_gain_dB = (int16_t)gain_table[index].gain_dB - diff_dB + 8; // get no closer than 8dB (bit of noise/spike immunity)
// scan the table to see what index to jump straight too
while (index > 1)
if (gain_table[--index].gain_dB <= desired_gain_dB)
break;
}
else
{ // incrementally reduce the gain .. taking it slow improves noise/spike immunity
if (index > 1)
index--; // slow step-by-step gain reduction
}
index = MAX(1u, index);
if (gain_table_index[vfo] != index)
{
gain_table_index[vfo] = index;
hold_counter[vfo] = 30; // 300ms hold
}
}
if (diff_dB >= -6) // 6dB hysterisis (help reduce gain hunting)
hold_counter[vfo] = 30; // 300ms hold
if (hold_counter[vfo] == 0)
{ // hold has been released, we're free to increase gain
const unsigned int index = gain_table_index[vfo] + 1; // move up to next gain index
gain_table_index[vfo] = MIN(index, gain_table_size - 1u);
}
{ // apply the new settings to the front end registers
const unsigned int index = gain_table_index[vfo];
// remember the new table index
gain_table_index_prev[vfo] = index;
currentGainDiff = gain_table[0].gain_dB - gain_table[index].gain_dB;
BK4819_WriteRegister(BK4819_REG_13, gain_table[index].reg_val);
#ifdef ENABLE_AGC_SHOW_DATA
UI_MAIN_PrintAGC(true);
#endif
}
#ifdef ENABLE_AM_FIX_SHOW_DATA
if (counter == 0) {
counter = 1;
gUpdateDisplay = true;
}
#endif
}
#ifdef ENABLE_AM_FIX_SHOW_DATA
void AM_fix_print_data(const unsigned vfo, char *s) {
if (s != NULL && vfo < ARRAY_SIZE(gain_table_index)) {
const unsigned int index = gain_table_index[vfo];
sprintf(s, "%2u %4ddB %3u", index, gain_table[index].gain_dB, prev_rssi[vfo]);
counter = 0;
}
}
#endif
int8_t AM_fix_get_gain_diff()
{
return currentGainDiff;
}
void AM_fix_enable(bool on)
{
enabled = on;
}
#endif