diff options
| author | Steve Markgraf <steve@steve-m.de> | 2012-09-16 16:24:58 +0200 |
|---|---|---|
| committer | Steve Markgraf <steve@steve-m.de> | 2012-09-16 16:24:58 +0200 |
| commit | 01d8d308fc42ab781d3f32cecb4d2bed3a673b70 (patch) | |
| tree | a7ff9896fd478d4d18d27ef94fc8fa3d52e182f8 | |
| parent | 519406264ce27459c6380dcf8dfa8c7b511d8e1b (diff) | |
disable second ADC in IF mode, make input selectable in DS-mode
Signed-off-by: Steve Markgraf <steve@steve-m.de>
| -rw-r--r-- | include/rtl-sdr.h | 2 | ||||
| -rw-r--r-- | src/librtlsdr.c | 18 |
2 files changed, 18 insertions, 2 deletions
diff --git a/include/rtl-sdr.h b/include/rtl-sdr.h index 98c9992..956b62b 100644 --- a/include/rtl-sdr.h +++ b/include/rtl-sdr.h @@ -236,7 +236,7 @@ RTLSDR_API int rtlsdr_set_agc_mode(rtlsdr_dev_t *dev, int on); * (xtal frequency of the RTL2832). * * \param dev the device handle given by rtlsdr_open() - * \param direct sampling mode, 1 means enabled, 0 disabled + * \param on 0 means disabled, 1 I-ADC input enabled, 2 Q-ADC input enabled * \return 0 on success */ RTLSDR_API int rtlsdr_set_direct_sampling(rtlsdr_dev_t *dev, int on); diff --git a/src/librtlsdr.c b/src/librtlsdr.c index f9aae37..529ab4f 100644 --- a/src/librtlsdr.c +++ b/src/librtlsdr.c @@ -955,6 +955,13 @@ int rtlsdr_set_direct_sampling(rtlsdr_dev_t *dev, int on) /* disable spectrum inversion */ r |= rtlsdr_demod_write_reg(dev, 1, 0x15, 0x00, 1); + /* only enable In-phase ADC input */ + r |= rtlsdr_demod_write_reg(dev, 0, 0x08, 0x4d, 1); + + /* swap I and Q ADC, this allows to select between two inputs */ + if (on > 1) + r |= rtlsdr_demod_write_reg(dev, 0, 0x06, 0x90, 1); + fprintf(stderr, "Enabled direct sampling mode\n"); dev->direct_sampling = 1; } else { @@ -970,10 +977,16 @@ int rtlsdr_set_direct_sampling(rtlsdr_dev_t *dev, int on) /* enable spectrum inversion */ r |= rtlsdr_demod_write_reg(dev, 1, 0x15, 0x01, 1); } else { + /* enable In-phase + Quadrature ADC input */ + r |= rtlsdr_demod_write_reg(dev, 0, 0x08, 0xcd, 1); + /* Enable Zero-IF mode */ - rtlsdr_demod_write_reg(dev, 1, 0xb1, 0x1b, 1); + r |= rtlsdr_demod_write_reg(dev, 1, 0xb1, 0x1b, 1); } + /* opt_adc_iq = 0, default ADC_I/ADC_Q datapath */ + r |= rtlsdr_demod_write_reg(dev, 0, 0x06, 0x80, 1); + fprintf(stderr, "Disabled direct sampling mode\n"); dev->direct_sampling = 0; } @@ -1193,6 +1206,9 @@ int rtlsdr_open(rtlsdr_dev_t **out_dev, uint32_t index) /* disable Zero-IF mode */ rtlsdr_demod_write_reg(dev, 1, 0xb1, 0x1a, 1); + /* only enable In-phase ADC input */ + rtlsdr_demod_write_reg(dev, 0, 0x08, 0x4d, 1); + /* the R820T uses 3.57 MHz IF for the DVB-T 6 MHz mode, and * 4.57 MHz for the 8 MHz mode */ rtlsdr_set_if_freq(dev, R820T_IF_FREQ); |