mirror/rtl-sdr-blog
1
0
Fork 0
mirror of https://github.com/rtlsdrblog/rtl-sdr-blog.git synced 2024-12-25 10:28:28 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

tuner_fc0013: improve tuning resolution

Browse Source 
We now use Hz instead of kHz for the internal
calculations, and thus improve the tuning resolution
to ~50 Hz (tested with DAB).

Signed-off-by: Steve Markgraf <steve@steve-m.de>
This commit is contained in:
Steve Markgraf 2012-05-27 15:33:11 +02:00
parent bcb8f2b28a
commit 75548c8bf3
2 changed files with 32 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/tuner_fc0013.h
View File

@ -30,7 +30,7 @@
#define FC0013_CHECK_VAL 0xa3 #define FC0013_CHECK_VAL 0xa3
int fc0013_init(void *dev); int fc0013_init(void *dev);
int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bw); int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth);
int fc0013_set_gain(void *dev, int gain); int fc0013_set_gain(void *dev, int gain);
#endif #endif

62
src/tuner_fc0013.c
View File

@ -168,21 +168,21 @@ static int fc0013_set_vhf_track(void *dev, uint32_t freq)
if (ret) if (ret)
goto error_out; goto error_out;
tmp &= 0xe3; tmp &= 0xe3;
if (freq <= 177500) { /* VHF Track: 7 */ if (freq <= 177500000) { /* VHF Track: 7 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c); ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c);
} else if (freq <= 184500) { /* VHF Track: 6 */ } else if (freq <= 184500000) { /* VHF Track: 6 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x18); ret = fc0013_writereg(dev, 0x1d, tmp | 0x18);
} else if (freq <= 191500) { /* VHF Track: 5 */ } else if (freq <= 191500000) { /* VHF Track: 5 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x14); ret = fc0013_writereg(dev, 0x1d, tmp | 0x14);
} else if (freq <= 198500) { /* VHF Track: 4 */ } else if (freq <= 198500000) { /* VHF Track: 4 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x10); ret = fc0013_writereg(dev, 0x1d, tmp | 0x10);
} else if (freq <= 205500) { /* VHF Track: 3 */ } else if (freq <= 205500000) { /* VHF Track: 3 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x0c); ret = fc0013_writereg(dev, 0x1d, tmp | 0x0c);
} else if (freq <= 219500) { /* VHF Track: 2 */ } else if (freq <= 219500000) { /* VHF Track: 2 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x08); ret = fc0013_writereg(dev, 0x1d, tmp | 0x08);
} else if (freq < 300000) { /* VHF Track: 1 */ } else if (freq < 300000000) { /* VHF Track: 1 */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x04); ret = fc0013_writereg(dev, 0x1d, tmp | 0x04);
} else { /* UHF and GPS */ } else { /* UHF and GPS */
ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c); ret = fc0013_writereg(dev, 0x1d, tmp | 0x1c);
} }
@ -190,23 +190,23 @@ error_out:
return ret; return ret;
} }
int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth) int fc0013_set_params(void *dev, uint32_t freq, uint32_t bandwidth)
{ {
int i, ret = 0; int i, ret = 0;
uint32_t freq = frequency / 1000;
uint8_t reg[7], am, pm, multi, tmp; uint8_t reg[7], am, pm, multi, tmp;
unsigned long f_vco; uint64_t f_vco;
uint16_t xtal_freq_khz_2, xin, xdiv; uint32_t xtal_freq_div_2;
uint16_t xin, xdiv;
int vco_select = 0; int vco_select = 0;
xtal_freq_khz_2 = rtlsdr_get_tuner_clock(dev) / 1000 / 2; xtal_freq_div_2 = rtlsdr_get_tuner_clock(dev) / 2;
/* set VHF track */ /* set VHF track */
ret = fc0013_set_vhf_track(dev, freq); ret = fc0013_set_vhf_track(dev, freq);
if (ret) if (ret)
goto exit; goto exit;
if (freq < 300000) { if (freq < 300000000) {
/* enable VHF filter */ /* enable VHF filter */
ret = fc0013_readreg(dev, 0x07, &tmp); ret = fc0013_readreg(dev, 0x07, &tmp);
if (ret) if (ret)
@ -222,7 +222,7 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
ret = fc0013_writereg(dev, 0x14, tmp & 0x1f); ret = fc0013_writereg(dev, 0x14, tmp & 0x1f);
if (ret) if (ret)
goto exit; goto exit;
} else if (freq <= 862000) { } else if (freq <= 862000000) {
/* disable VHF filter */ /* disable VHF filter */
ret = fc0013_readreg(dev, 0x07, &tmp); ret = fc0013_readreg(dev, 0x07, &tmp);
if (ret) if (ret)
@ -257,43 +257,43 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
} }
/* select frequency divider and the frequency of VCO */ /* select frequency divider and the frequency of VCO */
if (freq < 37084) { /* freq * 96 < 3560000 */ if (freq < 37084000) { /* freq * 96 < 3560000000 */
multi = 96; multi = 96;
reg[5] = 0x82; reg[5] = 0x82;
reg[6] = 0x00; reg[6] = 0x00;
} else if (freq < 55625) { /* freq * 64 < 3560000 */ } else if (freq < 55625000) { /* freq * 64 < 3560000000 */
multi = 64; multi = 64;
reg[5] = 0x02; reg[5] = 0x02;
reg[6] = 0x02; reg[6] = 0x02;
} else if (freq < 74167) { /* freq * 48 < 3560000 */ } else if (freq < 74167000) { /* freq * 48 < 3560000000 */
multi = 48; multi = 48;
reg[5] = 0x42; reg[5] = 0x42;
reg[6] = 0x00; reg[6] = 0x00;
} else if (freq < 111250) { /* freq * 32 < 3560000 */ } else if (freq < 111250000) { /* freq * 32 < 3560000000 */
multi = 32; multi = 32;
reg[5] = 0x82; reg[5] = 0x82;
reg[6] = 0x02; reg[6] = 0x02;
} else if (freq < 148334) { /* freq * 24 < 3560000 */ } else if (freq < 148334000) { /* freq * 24 < 3560000000 */
multi = 24; multi = 24;
reg[5] = 0x22; reg[5] = 0x22;
reg[6] = 0x00; reg[6] = 0x00;
} else if (freq < 222500) { /* freq * 16 < 3560000 */ } else if (freq < 222500000) { /* freq * 16 < 3560000000 */
multi = 16; multi = 16;
reg[5] = 0x42; reg[5] = 0x42;
reg[6] = 0x02; reg[6] = 0x02;
} else if (freq < 296667) { /* freq * 12 < 3560000 */ } else if (freq < 296667000) { /* freq * 12 < 3560000000 */
multi = 12; multi = 12;
reg[5] = 0x12; reg[5] = 0x12;
reg[6] = 0x00; reg[6] = 0x00;
} else if (freq < 445000) { /* freq * 8 < 3560000 */ } else if (freq < 445000000) { /* freq * 8 < 3560000000 */
multi = 8; multi = 8;
reg[5] = 0x22; reg[5] = 0x22;
reg[6] = 0x02; reg[6] = 0x02;
} else if (freq < 593334) { /* freq * 6 < 3560000 */ } else if (freq < 593334000) { /* freq * 6 < 3560000000 */
multi = 6; multi = 6;
reg[5] = 0x0a; reg[5] = 0x0a;
reg[6] = 0x00; reg[6] = 0x00;
} else if (freq < 950000) { /* freq * 4 < 3800000 */ } else if (freq < 950000000) { /* freq * 4 < 3800000000 */
multi = 4; multi = 4;
reg[5] = 0x12; reg[5] = 0x12;
reg[6] = 0x02; reg[6] = 0x02;
@ -305,15 +305,15 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
f_vco = freq * multi; f_vco = freq * multi;
if (f_vco >= 3060000) { if (f_vco >= 3060000000) {
reg[6] |= 0x08; reg[6] |= 0x08;
vco_select = 1; vco_select = 1;
} }
if (freq >= 45000) { if (freq >= 45000000) {
/* From divided value (XDIV) determined the FA and FP value */ /* From divided value (XDIV) determined the FA and FP value */
xdiv = (uint16_t)(f_vco / xtal_freq_khz_2); xdiv = (uint16_t)(f_vco / xtal_freq_div_2);
if ((f_vco - xdiv * xtal_freq_khz_2) >= (xtal_freq_khz_2 / 2)) if ((f_vco - xdiv * xtal_freq_div_2) >= (xtal_freq_div_2 / 2))
xdiv++; xdiv++;
pm = (uint8_t)(xdiv / 8); pm = (uint8_t)(xdiv / 8);
@ -337,8 +337,8 @@ int fc0013_set_params(void *dev, uint32_t frequency, uint32_t bandwidth)
/* From VCO frequency determines the XIN ( fractional part of Delta /* From VCO frequency determines the XIN ( fractional part of Delta
Sigma PLL) and divided value (XDIV) */ Sigma PLL) and divided value (XDIV) */
xin = (uint16_t)(f_vco - (f_vco / xtal_freq_khz_2) * xtal_freq_khz_2); xin = (uint16_t)((f_vco - (f_vco / xtal_freq_div_2) * xtal_freq_div_2) / 1000);
xin = (xin << 15) / xtal_freq_khz_2; xin = (xin << 15) / (xtal_freq_div_2 / 1000);
if (xin >= 16384) if (xin >= 16384)
xin += 32768; xin += 32768;