Hamlib/microtune/microtune_eval_board.cc

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/* -*-C++-*-
*******************************************************************************
*
* File: microtune_eval_board.cc
* Description:
*
*******************************************************************************
*/
/*
* Copyright 2001 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.
*/
#include "microtune_eval_board.h"
#include "microtune_eval_board_defs.h"
#include "serial.h"
#include "i2cio_pp.h"
#include "i2c.h"
#include <cmath>
static int AGC_DAC_I2C_ADDR = 0x2C;
microtune_eval_board::microtune_eval_board (hamlib_port_t *port)
{
m_ppio = port;
m_i2cio = new i2cio_pp (m_ppio);
m_i2c = new i2c (m_i2cio);
// disable upstream amplifier
par_lock (m_ppio);
unsigned char t;
par_read_data (m_ppio, &t);
t &= ~(UT_DP_TX_ENABLE | UT_DP_TX_SDA | UT_DP_TX_SCL);
t |= UT_DP_TX_AS;
par_write_data (m_ppio, t);
par_unlock (m_ppio);
}
microtune_eval_board::~microtune_eval_board ()
{
delete m_i2c;
delete m_i2cio;
delete m_i2c;
}
//! is the eval board present?
bool
microtune_eval_board::board_present_p ()
{
bool result = true;
par_lock (m_ppio);
unsigned char t;
par_read_status (m_ppio, &t);
if ((t & UT_SP_SHOULD_BE_ZERO) != 0
|| (t & UT_SP_SHOULD_BE_ONE) != UT_SP_SHOULD_BE_ONE)
result = false;
// could also see if SCL is looped back or not, but that seems like overkill
par_unlock (m_ppio);
return result;
}
// returns true iff successful
bool
microtune_eval_board::i2c_write (int addr, const unsigned char *buf, int nbytes)
{
return m_i2c->write (addr, buf, nbytes);
}
// returns number of bytes read or -1 if error
int
microtune_eval_board::i2c_read (int addr, unsigned char *buf, int max_bytes)
{
return m_i2c->read (addr, buf, max_bytes);
}
/*
* ----------------------------------------------------------------
* AGC stuff
*
* We're using a MAX518 8-bit 5V dual dac for setting the AGC's
* ----------------------------------------------------------------
*/
void
microtune_eval_board::write_dac (int which, int value)
{
unsigned char cmd[2];
cmd[0] = which & 1;
cmd[1] = value;
i2c_write (AGC_DAC_I2C_ADDR, cmd, sizeof (cmd));
}
void
microtune_eval_board::write_both_dacs (int value0, int value1)
{
unsigned char cmd[4];
cmd[0] = 0;
cmd[1] = value0;
cmd[2] = 1;
cmd[3] = value1;
i2c_write (AGC_DAC_I2C_ADDR, cmd, sizeof (cmd));
}
static int scale_volts (float volts)
{
int n;
n = (int) rint (volts * (256 / 5.0));
if (n < 0)
n = 0;
if (n > 255)
n = 255;
return n;
}
void
microtune_eval_board::set_RF_AGC_voltage (float volts)
{
write_dac (0, scale_volts (volts));
}
void
microtune_eval_board::set_IF_AGC_voltage (float volts)
{
write_dac (1, scale_volts (volts));
}
static const float RF_MIN_V = 1.5; // RF AGC control voltages
static const float RF_MAX_V = 4.0;
static const float IF_MIN_V = 2.0; // IF AGC control voltages
static const float IF_MAX_V = 4.0;
static const float MIN_AGC = 0; // bottom of synthetic range
static const float MAX_AGC = 1000; // top of synthetic range
static const float CUTOVER_POINT = 667;
// linear is in the range MIN_AGC to MAX_AGC
static float
linear_to_RF_AGC_voltage (float linear)
{
if (linear >= CUTOVER_POINT)
return RF_MAX_V;
float slope = (RF_MAX_V - RF_MIN_V) / CUTOVER_POINT;
return RF_MIN_V + linear * slope;
}
static float
linear_to_IF_AGC_voltage (float linear)
{
if (linear < CUTOVER_POINT)
return IF_MIN_V;
float slope = (IF_MAX_V - IF_MIN_V) / (MAX_AGC - CUTOVER_POINT);
return IF_MIN_V + (linear - CUTOVER_POINT) * slope;
}
void
microtune_eval_board::set_AGC (float v)
{
if (v < MIN_AGC)
v = MIN_AGC;
if (v > MAX_AGC)
v = MAX_AGC;
float rf_agc_voltage = linear_to_RF_AGC_voltage (v);
float if_agc_voltage = linear_to_IF_AGC_voltage (v);
set_RF_AGC_voltage (rf_agc_voltage);
set_IF_AGC_voltage (if_agc_voltage);
}