diff options
Diffstat (limited to 'host')
| -rw-r--r-- | host/lib/usrp/dboard/db_tvrx.cpp | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/host/lib/usrp/dboard/db_tvrx.cpp b/host/lib/usrp/dboard/db_tvrx.cpp index 2988367e2..f5b544c18 100644 --- a/host/lib/usrp/dboard/db_tvrx.cpp +++ b/host/lib/usrp/dboard/db_tvrx.cpp @@ -44,6 +44,7 @@ #include <utility> #include <cmath> #include <cfloat> +#include <limits> #include <tuner_4937di5_regs.hpp> using namespace uhd; @@ -59,10 +60,6 @@ static const freq_range_t tvrx_freq_range(50e6, 860e6); static const std::string tvrx_antennas = std::string(""); //only got one -//a note on these: the gain of the TVRX varies over frequency. the gain ranges -//below correspond to the maximum and minimum gains over the entire frequency range. -//specifying a gain higher or lower than the TVRX can accomplish will of course just clip. - static const uhd::dict<std::string, freq_range_t> tvrx_freq_ranges = map_list_of ("VHFLO", freq_range_t(50e6, 158e6)) ("VHFHI", freq_range_t(158e6, 454e6)) @@ -148,7 +145,7 @@ private: double _lo_freq; tuner_4937di5_regs_t _tuner_4937di5_regs; boost::uint8_t _tuner_4937di5_addr(void){ - return (this->get_iface()->get_special_props().mangle_i2c_addrs)? 0x60 : 0x61; //ok really? we could rename that call + return (this->get_iface()->get_special_props().mangle_i2c_addrs)? 0x61 : 0x60; //ok really? we could rename that call }; void set_gain(float gain, const std::string &name); @@ -182,7 +179,7 @@ static dboard_base::sptr make_tvrx(dboard_base::ctor_args_t args){ UHD_STATIC_BLOCK(reg_tvrx_dboard){ //register the factory function for the rx dbid - dboard_manager::register_dboard(0x0003, &make_tvrx, "tvrx"); + dboard_manager::register_dboard(0x0040, &make_tvrx, "tvrx"); } /*********************************************************************** @@ -203,6 +200,7 @@ tvrx::tvrx(ctor_args_t args) : rx_dboard_base(args){ //send initial register settings if necessary //set default freq + _lo_freq = tvrx_freq_range.min + tvrx_if_freq; //init _lo_freq to a sane default set_freq(tvrx_freq_range.min); //set default gains @@ -220,9 +218,12 @@ tvrx::~tvrx(void){ */ static std::string get_band(double freq) { + std::cout << "get_band called with freq " << freq << std::endl; BOOST_FOREACH(const std::string &band, tvrx_freq_ranges.keys()) { - if(freq >= tvrx_freq_ranges[band].min && freq <= tvrx_freq_ranges[band].max) + if(freq >= tvrx_freq_ranges[band].min && freq <= tvrx_freq_ranges[band].max){ + std::cout << "Holy poop you're in band " << band << std::endl; return band; + } } UHD_THROW_INVALID_CODE_PATH(); } @@ -245,15 +246,25 @@ static float gain_interp(float gain, boost::array<float, 17> db_vector, boost::a boost::uint8_t gain_step = 0; //find which bin we're in for(size_t i = 0; i < db_vector.size()-1; i++) { - if(gain > db_vector[i] && gain < db_vector[i+1]) gain_step = i; + if(gain >= db_vector[i] && gain <= db_vector[i+1]) gain_step = i; } //find the current slope for linear interpolation float slope = (volts_vector[gain_step + 1] - volts_vector[gain_step]) / (db_vector[gain_step + 1] - db_vector[gain_step]); + + //the problem here is that for gains approaching the maximum, the voltage slope becomes infinite + //i.e., a small change in gain requires an infinite change in voltage + //to cope, we limit the slope + + if(slope == std::numeric_limits<float>::infinity()) + return volts_vector[gain_step]; //use the volts per dB slope to find the final interpolated voltage volts = volts_vector[gain_step] + (slope * (gain - db_vector[gain_step])); + + if(tvrx_debug) + std::cout << "Gain interp: gain: " << gain << ", gain_step: " << int(gain_step) << ", slope: " << slope << ", volts: " << volts << std::endl; return volts; } @@ -276,6 +287,8 @@ static float rf_gain_to_voltage(float gain, double lo_freq){ float gain_volts = gain_interp(gain, tvrx_rf_gains_db[band], tvrx_gains_volts); //this is the voltage at the USRP DAC output float dac_volts = gain_volts / opamp_gain; + + dac_volts = std::clip<float>(dac_volts, 0.0, 3.3); if (tvrx_debug) std::cerr << boost::format( "tvrx RF AGC gain: %f dB, dac_volts: %f V" @@ -297,6 +310,8 @@ static float if_gain_to_voltage(float gain){ float gain_volts = gain_interp(gain, tvrx_if_gains_db, tvrx_gains_volts); float dac_volts = gain_volts / opamp_gain; + + dac_volts = std::clip<float>(dac_volts, 0.0, 3.3); if (tvrx_debug) std::cerr << boost::format( "tvrx IF AGC gain: %f dB, dac_volts: %f V" @@ -324,13 +339,13 @@ void tvrx::set_gain(float gain, const std::string &name){ void tvrx::set_freq(double freq) { freq = std::clip<float>(freq, tvrx_freq_range.min, tvrx_freq_range.max); - std::string prev_band = get_band(_lo_freq + tvrx_if_freq); + std::string prev_band = get_band(_lo_freq - tvrx_if_freq); std::string new_band = get_band(freq); - double lo_freq = freq + tvrx_if_freq; //the desired LO freq for high-side mixing + double target_lo_freq = freq + tvrx_if_freq; //the desired LO freq for high-side mixing double f_ref = reference_freq / double(reference_divider); //your tuning step size - int divisor = int(lo_freq + (f_ref * 4.0)) / (f_ref * 8); //the divisor we'll use + int divisor = int((target_lo_freq + (f_ref * 4.0)) / (f_ref * 8)); //the divisor we'll use double actual_lo_freq = (f_ref * 8 * divisor); //the LO freq we'll actually get if((divisor & ~0x7fff)) UHD_THROW_INVALID_CODE_PATH(); @@ -344,7 +359,7 @@ void tvrx::set_freq(double freq) { else if(new_band == "UHF") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_UHF; else UHD_THROW_INVALID_CODE_PATH(); - _tuner_4937di5_regs.power = tuner_4937di5_regs_t::POWER_ON; + _tuner_4937di5_regs.power = tuner_4937di5_regs_t::POWER_OFF; update_regs(); //ok don't forget to reset RF gain here if the new band != the old band @@ -352,6 +367,9 @@ void tvrx::set_freq(double freq) { //not FAR off, but we do this to be consistent if(prev_band != new_band) set_gain(_gains["RF"], "RF"); + if(tvrx_debug) + std::cout << boost::format("set_freq: target LO: %f f_ref: %f divisor: %i actual LO: %f") % target_lo_freq % f_ref % divisor % actual_lo_freq << std::endl; + _lo_freq = actual_lo_freq; //for rx props } @@ -386,7 +404,7 @@ void tvrx::rx_get(const wax::obj &key_, wax::obj &val){ return; case SUBDEV_PROP_FREQ: - val = _lo_freq - tvrx_if_freq; + val = _lo_freq - 2*tvrx_if_freq; return; case SUBDEV_PROP_FREQ_RANGE: |