dmfc.cpp

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/*
    Pegasus DMFC Focuser
    Copyright (C) 2017 Jasem Mutlaq (mutlaqja@ikarustech.com)
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.
 
    This library 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
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 
*/
 
#include "dmfc.h"
 
#include "indicom.h"
#include "connectionplugins/connectionserial.h"
 
#include <cmath>
#include <cstring>
#include <memory>
 
#include <termios.h>
#include <unistd.h>
 
#define DMFC_TIMEOUT 3
#define FOCUS_SETTINGS_TAB "Settings"
#define TEMPERATURE_THRESHOLD 0.1
 
static std::unique_ptr<DMFC> dmfc(new DMFC());
 
DMFC::DMFC()
{
    setVersion(1, 1);
 
    // Can move in Absolute & Relative motions, can AbortFocuser motion.
    FI::SetCapability(FOCUSER_CAN_ABS_MOVE |
                      FOCUSER_CAN_REL_MOVE |
                      FOCUSER_CAN_ABORT |
                      FOCUSER_CAN_REVERSE |
                      FOCUSER_CAN_SYNC |
                      FOCUSER_HAS_BACKLASH);
}
 
bool DMFC::initProperties()
{
    INDI::Focuser::initProperties();
 
    // Focuser temperature
    IUFillNumber(&TemperatureN[0], "TEMPERATURE", "Celsius", "%6.2f", -50, 70., 0., 0.);
    IUFillNumberVector(&TemperatureNP, TemperatureN, 1, getDeviceName(), "FOCUS_TEMPERATURE", "Temperature",
                       MAIN_CONTROL_TAB, IP_RO, 0, IPS_IDLE);
 
    // Max Speed
    IUFillNumber(&MaxSpeedN[0], "Value", "", "%6.2f", 100, 1000., 100., 400.);
    IUFillNumberVector(&MaxSpeedNP, MaxSpeedN, 1, getDeviceName(), "MaxSpeed", "", FOCUS_SETTINGS_TAB, IP_RW, 0, IPS_IDLE);
 
    // Encoders
    IUFillSwitch(&EncoderS[ENCODERS_ON], "On", "", ISS_ON);
    IUFillSwitch(&EncoderS[ENCODERS_OFF], "Off", "", ISS_OFF);
    IUFillSwitchVector(&EncoderSP, EncoderS, 2, getDeviceName(), "Encoders", "", FOCUS_SETTINGS_TAB, IP_RW, ISR_1OFMANY, 0,
                       IPS_IDLE);
 
    // Motor Modes
    IUFillSwitch(&MotorTypeS[MOTOR_DC], "DC", "DC", ISS_OFF);
    IUFillSwitch(&MotorTypeS[MOTOR_STEPPER], "Stepper", "Stepper", ISS_ON);
    IUFillSwitchVector(&MotorTypeSP, MotorTypeS, 2, getDeviceName(), "Motor Type", "", MAIN_CONTROL_TAB, IP_RW, ISR_1OFMANY,
                       0, IPS_IDLE);
 
    // LED
    IUFillSwitch(&LEDS[LED_OFF], "Off", "", ISS_ON);
    IUFillSwitch(&LEDS[LED_ON], "On", "", ISS_OFF);
    IUFillSwitchVector(&LEDSP, LEDS, 2, getDeviceName(), "LED", "", FOCUS_SETTINGS_TAB, IP_RW, ISR_1OFMANY, 0, IPS_IDLE);
 
    // Firmware Version
    IUFillText(&FirmwareVersionT[0], "Version", "Version", "");
    IUFillTextVector(&FirmwareVersionTP, FirmwareVersionT, 1, getDeviceName(), "Firmware", "Firmware", MAIN_CONTROL_TAB, IP_RO,
                     0, IPS_IDLE);
 
    // Relative and absolute movement
    FocusRelPosN[0].min   = 0.;
    FocusRelPosN[0].max   = 50000.;
    FocusRelPosN[0].value = 0;
    FocusRelPosN[0].step  = 1000;
 
    FocusAbsPosN[0].min   = 0.;
    FocusAbsPosN[0].max   = 100000;
    FocusAbsPosN[0].value = 0;
    FocusAbsPosN[0].step  = 1000;
 
    // Backlash compensation
    FocusBacklashN[0].min   = 1; // 0 is off.
    FocusBacklashN[0].max   = 1000;
    FocusBacklashN[0].value = 1;
    FocusBacklashN[0].step  = 1;
 
    //LED Default ON
    LEDS[LED_ON].s = ISS_ON;
    LEDS[LED_OFF].s = ISS_OFF;
 
    addDebugControl();
    setDefaultPollingPeriod(200);
    serialConnection->setDefaultBaudRate(Connection::Serial::B_19200);
 
    return true;
}
 
void DMFC::ISGetProperties(const char *dev)
{
    INDI::Focuser::ISGetProperties(dev);
    int configSwitch = MOTOR_STEPPER;
 
    // Try to read config value for motor type
    // If relative, then update the capability of the focuser as such.
    if (IUGetConfigOnSwitchIndex(getDeviceName(), MotorTypeSP.name, &configSwitch) == 0)
    {
        // We are only relative focuser now.
        if (configSwitch == MOTOR_DC)
            FI::SetCapability(GetCapability() & ~(FOCUSER_CAN_ABS_MOVE | FOCUSER_CAN_SYNC));
        else
            FI::SetCapability(GetCapability() | (FOCUSER_CAN_ABS_MOVE | FOCUSER_CAN_SYNC));
 
        MotorTypeSP.s = IPS_OK;
    }
 
    IUResetSwitch(&MotorTypeSP);
    MotorTypeS[configSwitch].s = ISS_ON;
    defineProperty(&MotorTypeSP);
}
 
bool DMFC::updateProperties()
{
    INDI::Focuser::updateProperties();
 
    if (isConnected())
    {
        defineProperty(&TemperatureNP);
        defineProperty(&EncoderSP);
        defineProperty(&MaxSpeedNP);
        defineProperty(&LEDSP);
        defineProperty(&FirmwareVersionTP);
    }
    else
    {
        deleteProperty(TemperatureNP.name);
        deleteProperty(EncoderSP.name);
        deleteProperty(MaxSpeedNP.name);
        deleteProperty(LEDSP.name);
        deleteProperty(FirmwareVersionTP.name);
    }
 
    return true;
}
 
bool DMFC::Handshake()
{
    if (ack())
    {
        LOGF_INFO("%s is online. Getting focus parameters...", this->getDeviceName());
 
        // Set motor type on startup only.
        setMotorType((MotorTypeS[MOTOR_DC].s == ISS_ON) ? MOTOR_DC : MOTOR_STEPPER);
 
        return true;
    }
 
    LOGF_INFO(
        "Error retrieving data from %s, please ensure device is powered and the port is correct.", this->getDeviceName());
    return false;
}
 
 
const char *DMFC::getDefaultName()
{
    return "Pegasus DMFC";
}
 
bool DMFC::ack()
{
    int nbytes_written = 0, nbytes_read = 0, rc = -1;
    char errstr[MAXRBUF];
    char cmd[2] = {0};
    char res[16] = {0};
 
    cmd[0] = '#';
    cmd[1] = 0xA;
 
    LOGF_DEBUG("CMD <%#02X>", cmd[0]);
 
    tcflush(PortFD, TCIOFLUSH);
 
    if ((rc = tty_write(PortFD, cmd, 2, &nbytes_written)) != TTY_OK)
    {
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Ack error: %s.", errstr);
        return false;
    }
 
    if ((rc = tty_read_section(PortFD, res, 0xA, DMFC_TIMEOUT, &nbytes_read)) != TTY_OK)
    {
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Ack error: %s.", errstr);
        return false;
    }
 
    // Get rid of 0xA
    res[nbytes_read - 1] = 0;
 
 
    if( res[nbytes_read - 2] == '\r') res[nbytes_read - 2] = 0;
 
    LOGF_DEBUG("RES <%s>", res);
 
    tcflush(PortFD, TCIOFLUSH);
 
    if((strstr(res, "OK_DMFCN") != nullptr) || (strstr(res, "OK_SMFC") != nullptr) || (strstr(res, "OK_PRDG") != nullptr))
        return true;
 
    return false;
}
 
 
bool DMFC::SyncFocuser(uint32_t ticks)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "W:%ud", ticks);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    // Set Position
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("sync error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
 
    return true;
}
 
bool DMFC::moveAbsolute(uint32_t newPosition)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "M:%ud", newPosition);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    // Set Position
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Absolute move error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
 
    return true;
}
 
bool DMFC::moveRelative(int relativePosition)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "G:%d", relativePosition);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    // Set Relative Position
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Relative move error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
 
    return true;
}
 
bool DMFC::ISNewSwitch(const char *dev, const char *name, ISState *states, char *names[], int n)
{
    if (dev != nullptr && strcmp(dev, getDeviceName()) == 0)
    {
        // Motor Type
        if (!strcmp(name, MotorTypeSP.name))
        {
            IUUpdateSwitch(&MotorTypeSP, states, names, n);
            MotorTypeSP.s = IPS_OK;
            saveConfig(true, MotorTypeSP.name);
 
            // If we're not connected, let's then set the capability now.
            if (!isConnected())
            {
                // We are only relative focuser now.
                if (MotorTypeS[MOTOR_DC].s == ISS_ON)
                    FI::SetCapability(GetCapability() & ~(FOCUSER_CAN_ABS_MOVE | FOCUSER_CAN_SYNC));
                else
                    FI::SetCapability(GetCapability() | (FOCUSER_CAN_ABS_MOVE | FOCUSER_CAN_SYNC));
            }
            else
                LOG_INFO("Motor type changed. Please restart driver for this change to take effect.");
 
            IDSetSwitch(&MotorTypeSP, nullptr);
            return true;
        }
 
        // Encoders
        if (!strcmp(name, EncoderSP.name))
        {
            IUUpdateSwitch(&EncoderSP, states, names, n);
            bool rc = setEncodersEnabled(EncoderS[ENCODERS_ON].s == ISS_ON);
            EncoderSP.s = rc ? IPS_OK : IPS_ALERT;
            IDSetSwitch(&EncoderSP, nullptr);
            return true;
        }
 
        // LED
        if (!strcmp(name, LEDSP.name))
        {
            IUUpdateSwitch(&LEDSP, states, names, n);
            bool rc = setLedEnabled(LEDS[LED_ON].s == ISS_ON);
            LEDSP.s = rc ? IPS_OK : IPS_ALERT;
            IDSetSwitch(&LEDSP, nullptr);
            return true;
        }
    }
    return INDI::Focuser::ISNewSwitch(dev, name, states, names, n);
}
 
bool DMFC::ISNewNumber(const char *dev, const char *name, double values[], char *names[], int n)
{
    if (dev != nullptr && strcmp(dev, getDeviceName()) == 0)
    {
        // MaxSpeed
        if (strcmp(name, MaxSpeedNP.name) == 0)
        {
            IUUpdateNumber(&MaxSpeedNP, values, names, n);
            bool rc = setMaxSpeed(MaxSpeedN[0].value);
            MaxSpeedNP.s = rc ? IPS_OK : IPS_ALERT;
            IDSetNumber(&MaxSpeedNP, nullptr);
            return true;
        }
    }
 
    return INDI::Focuser::ISNewNumber(dev, name, values, names, n);
}
 
void DMFC::ignoreResponse()
{
    int nbytes_read = 0;
    char res[64];
    tty_read_section(PortFD, res, 0xA, DMFC_TIMEOUT, &nbytes_read);
}
 
bool DMFC::updateFocusParams()
{
    int nbytes_written = 0, nbytes_read = 0, rc = -1;
    char errstr[MAXRBUF];
    char cmd[3] = {0};
    char res[64];
    cmd[0] = 'A';
    cmd[1] = 0xA;
 
    LOGF_DEBUG("CMD <%#02X>", cmd[0]);
 
    tcflush(PortFD, TCIOFLUSH);
 
    if ((rc = tty_write(PortFD, cmd, 2, &nbytes_written)) != TTY_OK)
    {
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("GetFocusParams error: %s.", errstr);
        return false;
    }
 
 
    if ((rc = tty_read_section(PortFD, res, 0xA, DMFC_TIMEOUT, &nbytes_read)) != TTY_OK)
    {
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("GetFocusParams error: %s.", errstr);
        return false;
    }
 
    res[nbytes_read - 1] = 0;
 
    // Check for '\r' at end of string and replace with nullptr (DMFC firmware version 2.8)
    if( res[nbytes_read - 2] == '\r') res[nbytes_read - 2] = 0;
 
    LOGF_DEBUG("RES <%s>", res);
 
    tcflush(PortFD, TCIOFLUSH);
 
    char *token = std::strtok(res, ":");
 
 
    // #1 Status
    if (token == nullptr || ((strstr(token, "OK_DMFCN") == nullptr) && (strstr(token, "OK_SMFC") == nullptr)
                             && (strstr(token, "OK_PRDG") == nullptr)))
    {
        LOGF_ERROR("Invalid status response. %s", res);
        return false;
    }
 
    // #2 Version
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid version response.");
        return false;
    }
 
    if (FirmwareVersionT[0].text == nullptr || strcmp(FirmwareVersionT[0].text, token))
    {
        IUSaveText(&FirmwareVersionT[0], token);
        FirmwareVersionTP.s = IPS_OK;
        IDSetText(&FirmwareVersionTP, nullptr);
    }
 
    // #3 Motor Type
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid motor mode response.");
        return false;
    }
 
    int motorType = atoi(token);
 
 
    if (motorType >= 0 && motorType <= 1)
    {
        //1 stepper
        //0 dc
        IUResetSwitch(&MotorTypeSP);
        MotorTypeS[MOTOR_DC].s = (motorType == 0) ? ISS_ON : ISS_OFF;
        MotorTypeS[MOTOR_STEPPER].s = (motorType == 1) ? ISS_ON : ISS_OFF;
        MotorTypeSP.s = IPS_OK;
        IDSetSwitch(&MotorTypeSP, nullptr);
    }
 
    // #4 Temperature
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid temperature response.");
        return false;
    }
 
    double temperature = atof(token);
    if (temperature == -127)
    {
        TemperatureNP.s = IPS_ALERT;
        IDSetNumber(&TemperatureNP, nullptr);
    }
    else
    {
        if (fabs(temperature - TemperatureN[0].value) > TEMPERATURE_THRESHOLD)
        {
            TemperatureN[0].value = temperature;
            TemperatureNP.s = IPS_OK;
            IDSetNumber(&TemperatureNP, nullptr);
        }
    }
 
    // #5 Position
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid position response.");
        return false;
    }
 
    currentPosition = atoi(token);
    if (currentPosition != FocusAbsPosN[0].value)
    {
        FocusAbsPosN[0].value = currentPosition;
        IDSetNumber(&FocusAbsPosNP, nullptr);
    }
 
    // #6 Moving Status
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid moving status response.");
        return false;
    }
 
    isMoving = (token[0] == '1');
 
    // #7 LED Status
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid LED response.");
        return false;
    }
 
    int ledStatus = atoi(token);
    if (ledStatus >= 0 && ledStatus <= 1)
    {
        IUResetSwitch(&LEDSP);
        LEDS[ledStatus].s = ISS_ON;
        LEDSP.s = IPS_OK;
        IDSetSwitch(&LEDSP, nullptr);
    }
 
    // #8 Reverse Status
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid reverse response.");
        return false;
    }
 
    int reverseStatus = atoi(token);
    if (reverseStatus >= 0 && reverseStatus <= 1)
    {
        IUResetSwitch(&FocusReverseSP);
        FocusReverseS[INDI_ENABLED].s = (reverseStatus == 1) ? ISS_ON : ISS_OFF;
        FocusReverseS[INDI_DISABLED].s = (reverseStatus == 0) ? ISS_ON : ISS_OFF;
        FocusReverseSP.s = IPS_OK;
        IDSetSwitch(&FocusReverseSP, nullptr);
    }
 
    // #9 Encoder status
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid encoder response.");
        return false;
    }
 
    int encoderStatus = atoi(token);
    if (encoderStatus >= 0 && encoderStatus <= 1)
    {
        IUResetSwitch(&EncoderSP);
        EncoderS[encoderStatus].s = ISS_ON;
        EncoderSP.s = IPS_OK;
        IDSetSwitch(&EncoderSP, nullptr);
    }
 
    // #10 Backlash
    token = std::strtok(nullptr, ":");
 
    if (token == nullptr)
    {
        LOG_ERROR("Invalid encoder response.");
        return false;
    }
 
    int backlash = atoi(token);
    // If backlash is zero then compensation is disabled
    if (backlash == 0 && FocusBacklashS[INDI_ENABLED].s == ISS_ON)
    {
        LOG_WARN("Backlash value is zero, disabling backlash switch...");
 
        FocusBacklashS[INDI_ENABLED].s = ISS_OFF;
        FocusBacklashS[INDI_DISABLED].s = ISS_ON;
        FocusBacklashSP.s = IPS_IDLE;
        IDSetSwitch(&FocusBacklashSP, nullptr);
    }
    else if (backlash > 0 && (FocusBacklashS[INDI_DISABLED].s == ISS_ON || backlash != FocusBacklashN[0].value))
    {
        if (backlash != FocusBacklashN[0].value)
        {
            FocusBacklashN[0].value = backlash;
            FocusBacklashNP.s = IPS_OK;
            IDSetNumber(&FocusBacklashNP, nullptr);
        }
 
        if (FocusBacklashS[INDI_DISABLED].s == ISS_ON)
        {
            FocusBacklashS[INDI_ENABLED].s = ISS_OFF;
            FocusBacklashS[INDI_DISABLED].s = ISS_ON;
            FocusBacklashSP.s = IPS_IDLE;
            IDSetSwitch(&FocusBacklashSP, nullptr);
        }
    }
 
    return true;
}
 
bool DMFC::setMaxSpeed(uint16_t speed)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "S:%d", speed);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Set Speed
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("setMaxSpeed error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
    return true;
}
 
bool DMFC::ReverseFocuser(bool enabled)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "N:%d", enabled ? 1 : 0);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Reverse
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Reverse error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
 
    return true;
}
 
bool DMFC::setLedEnabled(bool enable)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "L:%d", enable ? 2 : 1);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Led
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Led error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
    return true;
}
 
bool DMFC::setEncodersEnabled(bool enable)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "E:%d", enable ? 0 : 1);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Encoders
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Encoder error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
    return true;
}
 
bool DMFC::SetFocuserBacklash(int32_t steps)
{
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    snprintf(cmd, 16, "C:%d", steps);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Backlash
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Backlash error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
    return true;
}
 
bool DMFC::SetFocuserBacklashEnabled(bool enabled)
{
    if (!enabled)
        return SetFocuserBacklash(0);
 
    return SetFocuserBacklash(FocusBacklashN[0].value > 0 ? FocusBacklashN[0].value : 1);
}
 
bool DMFC::setMotorType(uint8_t type)
{
 
    int nbytes_written = 0, rc = -1;
    char cmd[16] = {0};
 
    //commands:
    //2 dc
    //1 stepper
    snprintf(cmd, 16, "R:%d", (type == MOTOR_STEPPER) ? 1 : 2);
    cmd[strlen(cmd)] = 0xA;
 
    LOGF_DEBUG("CMD <%s>", cmd);
 
    tcflush(PortFD, TCIOFLUSH);
 
    // Motor Type
    if ((rc = tty_write(PortFD, cmd, strlen(cmd), &nbytes_written)) != TTY_OK)
    {
        char errstr[MAXRBUF];
        tty_error_msg(rc, errstr, MAXRBUF);
        LOGF_ERROR("Motor type error: %s.", errstr);
        return false;
    }
 
    this->ignoreResponse();
 
    return true;
}
 
IPState DMFC::MoveAbsFocuser(uint32_t targetTicks)
{
    targetPosition = targetTicks;
 
    bool rc = moveAbsolute(targetPosition);
 
    if (!rc)
        return IPS_ALERT;
 
    FocusAbsPosNP.s = IPS_BUSY;
 
    return IPS_BUSY;
}
 
IPState DMFC::MoveRelFocuser(FocusDirection dir, uint32_t ticks)
{
    int relativePosition = ticks * ((dir == FOCUS_INWARD) ? -1 : 1);
    return moveRelative(relativePosition) ? IPS_BUSY : IPS_ALERT;
}
 
void DMFC::TimerHit()
{
    if (!isConnected())
    {
        SetTimer(getCurrentPollingPeriod());
        return;
    }
 
    bool rc = updateFocusParams();
 
    if (rc)
    {
        if (FocusAbsPosNP.s == IPS_BUSY || FocusRelPosNP.s == IPS_BUSY)
        {
            if (isMoving == false)
            {
                FocusAbsPosNP.s = IPS_OK;
                FocusRelPosNP.s = IPS_OK;
                IDSetNumber(&FocusAbsPosNP, nullptr);
                IDSetNumber(&FocusRelPosNP, nullptr);
                LOG_INFO("Focuser reached requested position.");
            }
        }
    }
 
    SetTimer(getCurrentPollingPeriod());
}
 
bool DMFC::AbortFocuser()
{
    int nbytes_written;
    char cmd[2] = { 'H', 0xA };
 
    if (tty_write(PortFD, cmd, 2, &nbytes_written) == TTY_OK)
    {
        FocusAbsPosNP.s = IPS_IDLE;
        FocusRelPosNP.s = IPS_IDLE;
        IDSetNumber(&FocusAbsPosNP, nullptr);
        IDSetNumber(&FocusRelPosNP, nullptr);
        this->ignoreResponse();
        return true;
    }
    else
        return false;
}
 
bool DMFC::saveConfigItems(FILE *fp)
{
    INDI::Focuser::saveConfigItems(fp);
    IUSaveConfigSwitch(fp, &MotorTypeSP);
    IUSaveConfigSwitch(fp, &EncoderSP);
    IUSaveConfigNumber(fp, &MaxSpeedNP);
    IUSaveConfigSwitch(fp, &LEDSP);
 
    return true;
}