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
|
#
# 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),))
|
