From 5d69a524f81f234b3fbc41d49ba18d6f6886baba Mon Sep 17 00:00:00 2001 From: jcorgan Date: Thu, 3 Aug 2006 04:51:51 +0000 Subject: Houston, we have a trunk. git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3122 221aa14e-8319-0410-a670-987f0aec2ac5 --- gr-usrp/src/db_tv_rx.py | 198 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 gr-usrp/src/db_tv_rx.py (limited to 'gr-usrp/src/db_tv_rx.py') diff --git a/gr-usrp/src/db_tv_rx.py b/gr-usrp/src/db_tv_rx.py new file mode 100644 index 000000000..05504553a --- /dev/null +++ b/gr-usrp/src/db_tv_rx.py @@ -0,0 +1,198 @@ +# +# Copyright 2005 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2, or (at your option) +# any later version. +# +# GNU Radio is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. +# + +__all__ = ['tv_rx'] + +import math +import usrp_dbid +import db_base +import db_instantiator + +def int_seq_to_str(seq): + """convert a sequence of integers into a string""" + return ''.join (map (chr, seq)) + +def str_to_int_seq(str): + """convert a string to a list of integers""" + return map (ord, str) + +def control_byte_1(fast_tuning_p, reference_divisor): + c = 0x88 + if fast_tuning_p: + c |= 0x40 + if reference_divisor == 512: + c |= 0x3 << 1 + elif reference_divisor == 640: + c |= 0x0 << 1 + elif reference_divisor == 1024: + c |= 0x1 << 1 + else: + assert 0 + return c + +def control_byte_2(target_freq, shutdown_tx_PGA): + if target_freq < 158e6: # VHF low + c = 0xa0 + elif target_freq < 464e6: # VHF high + c = 0x90 + else: # UHF + c = 0x30 + if shutdown_tx_PGA: + c |= 0x08 + return c + +class db_tv_rx(db_base.db_base): + def __init__(self, usrp, which, first_IF, second_IF): + """ + Control Microtune 4937 based USRP daughterboard. + + @param usrp: instance of usrp.source_c + @param which: which side: 0 or 1 corresponding to RX_A or RX_B respectively + @type which: int + """ + # sets _u and _which + db_base.db_base.__init__(self, usrp, which) + + self._i2c_addr = (0x60, 0x61)[which] + + self._first_IF = first_IF + self._second_IF = second_IF + self._reference_divisor = 640 + self._fast_tuning = False + self._inverted = False # FIXME get rid of this + + g = self.gain_range() # initialize gain + self.set_gain(float(g[0]+g[1]) / 2) + + self.bypass_adc_buffers(False) + + # Gain setting + def _set_rfagc(self,gain): + assert gain <= 60 and gain >= 0 + # FIXME this has a 0.5V step between gain = 60 and gain = 59. + # Why are there two cases instead of a single linear case? + if gain == 60: + voltage = 4 + else: + voltage = gain/60.0 * 2.25 + 1.25 + dacword = int(4096*voltage/1.22/3.3) # 1.22 = opamp gain + + assert dacword>=0 and dacword<4096 + self._u.write_aux_dac(self._which, 1, dacword) + + def _set_ifagc(self,gain): + assert gain <= 35 and gain >= 0 + voltage = gain/35.0 * 2.1 + 1.4 + dacword = int(4096*voltage/1.22/3.3) # 1.22 = opamp gain + + assert dacword>=0 and dacword<4096 + self._u.write_aux_dac(self._which, 0, dacword) + + def _set_pga(self,pga_gain): + assert pga_gain >=0 and pga_gain <=20 + if(self._which == 0): + self._u.set_pga (0, pga_gain) + else: + self._u.set_pga (2, pga_gain) + + def gain_range(self): + return (0, 115, 1) + + def set_gain(self,gain): + assert gain>=0 and gain<=115 + if gain>60: + rfgain = 60 + gain = gain - 60 + else: + rfgain = gain + gain = 0 + if gain > 35: + ifgain = 35 + gain = gain - 35 + else: + ifgain = gain + gain = 0 + pgagain = gain + self._set_rfagc(rfgain) + self._set_ifagc(ifgain) + self._set_pga(pgagain) + + def freq_range(self): + return (50e6, 860e6, 10e3) + + def set_freq(self, target_freq): + """ + @returns (ok, actual_baseband_freq) where: + ok is True or False and indicates success or failure, + actual_baseband_freq is the RF frequency that corresponds to DC in the IF. + """ + r = self.freq_range() + if target_freq < r[0] or target_freq > r[1]: + return (False, 0) + + target_lo_freq = target_freq + self._first_IF; # High side mixing + f_ref = 4e6 / self._reference_divisor # frequency steps + + divisor = int((target_lo_freq + (f_ref * 4)) / (f_ref * 8)) + actual_lo_freq = (f_ref * 8 * divisor) + actual_freq = actual_lo_freq - self._first_IF; + + if (divisor & ~0x7fff) != 0: # must be 15-bits or less + return (False, 0) + + # build i2c command string + buf = [0] * 4 + buf[0] = (divisor >> 8) & 0xff # DB1 + buf[1] = divisor & 0xff # DB2 + buf[2] = control_byte_1(self._fast_tuning, self._reference_divisor) + buf[3] = control_byte_2(actual_freq, True) + + ok = self._u.write_i2c(self._i2c_addr, int_seq_to_str (buf)) + + return (ok, actual_freq - self._second_IF) + + def is_quadrature(self): + """ + Return True if this board requires both I & Q analog channels. + + This bit of info is useful when setting up the USRP Rx mux register. + """ + return False + + def spectrum_inverted(self): + """ + The 43.75 MHz version is inverted + """ + return self._inverted + +# hook this daughterboard class into the auto-instantiation framework + +# With MT4937DI5-3x7702 with second downconversion +db_instantiator.add(usrp_dbid.TV_RX, + lambda usrp, which : (db_tv_rx(usrp, which, 43.75e6, 5.75e6),)) + +# With MT4937DI5-3x8680, and 3x8769 without second downconversion +db_instantiator.add(usrp_dbid.TV_RX_REV_2, + lambda usrp, which : (db_tv_rx(usrp, which, 44e6, 20e6),)) + +# With MT4937DI5-3x7901 without second downconversion, basically the same as tvrx2 +db_instantiator.add(usrp_dbid.TV_RX_REV_3, + lambda usrp, which : (db_tv_rx(usrp, which, 44e6, 20e6),)) -- cgit