Implement initial skywatcher rotator

Use GOTO mode when setting position.
Use cache for CPR (Counts Per Revolution) because it is hardcoded for the motor

configure.ac

@@ -67,7 +67,7 @@ dnl Beware of duplication should a backend directory include both rig and
 dnl rotor definitions, e.g. "dummy".  Optional backends will not be listed
 dnl here but will be added later, e.g. "winradio".
 RIG_BACKEND_LIST="rigs/adat rigs/alinco rigs/aor rigs/barrett rigs/codan rigs/dorji rigs/drake rigs/dummy rigs/elad rigs/flexradio rigs/icom rigs/icmarine rigs/jrc rigs/kachina rigs/kenwood rigs/kit rigs/lowe rigs/pcr rigs/prm80 rigs/racal rigs/rft rigs/rs rigs/skanti rigs/tapr rigs/tentec rigs/tuner rigs/uniden rigs/winradio rigs/wj rigs/yaesu rigs/gomspace rigs/mds rigs/anytone rigs/motorola rigs/commradio"
-ROT_BACKEND_LIST="rotators/amsat rotators/apex rotators/ars rotators/celestron rotators/cnctrk rotators/grbltrk rotators/easycomm rotators/ether6 rotators/flir rotators/fodtrack rotators/gs232a rotators/heathkit rotators/m2 rotators/meade rotators/rotorez rotators/sartek rotators/saebrtrack rotators/spid rotators/ts7400 rotators/prosistel rotators/ioptron rotators/satel rotators/radant"
+ROT_BACKEND_LIST="rotators/amsat rotators/apex rotators/ars rotators/celestron rotators/cnctrk rotators/grbltrk rotators/easycomm rotators/ether6 rotators/flir rotators/fodtrack rotators/gs232a rotators/heathkit rotators/m2 rotators/meade rotators/rotorez rotators/sartek rotators/saebrtrack rotators/spid rotators/ts7400 rotators/prosistel rotators/ioptron rotators/satel rotators/skywatcher rotators/radant"
 # Amplifiers are all in the amplifiers directory
 AMP_BACKEND_LIST="amplifiers/elecraft amplifiers/gemini amplifiers/expert"
 
@@ -898,6 +898,7 @@ rotators/spid/Makefile
 rotators/ts7400/Makefile
 rotators/indi/Makefile
 rotators/satel/Makefile
+rotators/skywatcher/Makefile
 rotators/radant/Makefile
 rigs/adat/Makefile
 rigs/alinco/Makefile

include/hamlib/rotlist.h

@@ -702,6 +702,18 @@
 //! @endcond
 #define ROT_MODEL_SAEBRTRACK ROT_MAKE_MODEL(ROT_SAEBRTRACK, 1)
 
+/**
+ * \brief A macro that returns the model number of the SKYWATCHER backend.
+ *
+ * \def ROT_MODEL_SKYWATCHER
+ *
+ * The SKYWATCHER backend can be used with SKYWATCHER * rotators.
+ */
+//! @cond Doxygen_Suppress
+#define ROT_SKYWATCHER 28
+#define ROT_BACKEND_SKYWATCHER "SkyWatcher"
+//! @endcond
+#define ROT_MODEL_SKYWATCHER ROT_MAKE_MODEL(ROT_SKYWATCHER, 1)
 
 /**
  * \brief Convenience type definition for a rotator model.

rotators/skywatcher/Android.mk

@@ -0,0 +1,12 @@
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := skywatcher.c
+LOCAL_MODULE := skywatcher
+
+LOCAL_CFLAGS := 
+LOCAL_C_INCLUDES := android include src
+LOCAL_LDLIBS := -lhamlib -Lobj/local/$(TARGET_ARCH_ABI)
+
+include $(BUILD_STATIC_LIBRARY)

rotators/skywatcher/Makefile.am

@@ -0,0 +1,5 @@
+
+noinst_LTLIBRARIES = libhamlib-skywatcher.la
+libhamlib_skywatcher_la_SOURCES = skywatcher.c skywatcher.h
+
+EXTRA_DIST = Android.mk

rotators/skywatcher/skywatcher.c

@@ -0,0 +1,249 @@
+#include <stdlib.h>
+#include "skywatcher.h"
+#include "register.h"
+#include "serial.h"
+
+#define ERROR_CHECK(x)           \
+  do {                           \
+    int __err_rc = (x);          \
+    if (__err_rc != RIG_OK) { \
+      return __err_rc;           \
+    }                            \
+  } while (0)
+
+static const int skywatcher_error_codes_length = 9;
+static const char *skywatcher_error_codes[skywatcher_error_codes_length] = {
+    "Unknown Command",
+    "Command Length Error",
+    "Motor not Stopped",
+    "Invalid Character",
+    "Not Initialized",
+    "Driver Sleeping",
+    "Unknown",
+    "PEC Training is running",
+    "No Valid PEC data"
+};
+
+typedef struct {
+  uint32_t cpr[2];
+} skywatcher_priv_data;
+
+static int skywatcher_cmd(ROT *rot, const char *cmd, char *response, size_t response_len) {
+  hamlib_port_t *port = ROTPORT(rot);
+  rig_flush(port);
+  size_t cmd_len = strlen(cmd);
+  ERROR_CHECK(write_block(port, (unsigned char *) cmd, cmd_len));
+  // echo from the device
+  int code = read_string(port, (unsigned char *) response, response_len, "\r", 1, 0, 1);
+  if (code < 0) {
+    return -code;
+  }
+  // the actual response
+  code = read_string(port, (unsigned char *) response, response_len, "\r", 1, 0, 1);
+  if (code < 0) {
+    return -code;
+  }
+  // nullify last \r
+  response[strlen(response) - 1] = '\0';
+  if (response[0] == '!') {
+    code = atoi(&response[1]);
+    if (code < skywatcher_error_codes_length) {
+      rig_debug(RIG_DEBUG_ERR, "Error code: %d Message: '%s'\n", code, skywatcher_error_codes[code]);
+    } else {
+      rig_debug(RIG_DEBUG_ERR, "Error response: '%s'\n", response);
+    }
+    return RIG_EPROTO;
+  }
+  // remove leading '='
+  memmove(response, response + 1, strlen(response) - 1);
+  response[strlen(response) - 1] = '\0';
+  return RIG_OK;
+}
+
+inline uint32_t skywatcher_convert24bit(long input) {
+  return ((input & 0x0000FF) << 16) | (input & 0x00FF00) | ((input & 0xFF0000) >> 16);
+}
+
+static const char *skywatcher_get_info(ROT *rot) {
+  static char info[32];
+  char str[16];
+
+  rig_debug(RIG_DEBUG_TRACE, "%s called\n", __func__);
+
+  // Read from 1st motor only. In practice both motors have the same version
+  if (skywatcher_cmd(rot, ":e1\r", str, sizeof(str)) != RIG_OK) {
+    return NULL;
+  }
+
+  SNPRINTF(info, sizeof(info), "V%s", str);
+
+  return info;
+}
+
+int skywatcher_get_spr(ROT *rot, int motor_index, uint32_t *result) {
+  skywatcher_priv_data *priv = ROTSTATE(rot)->priv;
+  if (priv->cpr[motor_index - 1] != 0) {
+    *result = priv->cpr[motor_index - 1];
+    return RIG_OK;
+  }
+  char str[16];
+  char req[16];
+  SNPRINTF(req, sizeof(req), ":a%d\r", motor_index);
+  ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+  priv->cpr[motor_index - 1] = skywatcher_convert24bit(strtol(str, NULL, 16));
+  *result = priv->cpr[motor_index - 1];
+  return RIG_OK;
+}
+
+int skywatcher_get_motor_position(ROT *rot, int motor_index, float *result) {
+  char str[16];
+  char req[16];
+  SNPRINTF(req, sizeof(req), ":j%d\r", motor_index);
+  ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+  long motor_ticks = skywatcher_convert24bit(strtol(str, NULL, 16)) - 0x800000;
+  uint32_t cpr;
+  ERROR_CHECK(skywatcher_get_spr(rot, motor_index, &cpr));
+  double ticks_per_angle = (double) cpr / 360.0;
+  *result = (float) ((double) motor_ticks / ticks_per_angle);
+  return RIG_OK;
+}
+
+static int skywatcher_get_position(ROT *rot, azimuth_t *az, elevation_t *el) {
+  rig_debug(RIG_DEBUG_TRACE, "%s called\n", __func__);
+
+  ERROR_CHECK(skywatcher_get_motor_position(rot, 1, (float *) az));
+  // normalize to 0 ~ 360
+  if (*az < 0.0f) {
+    *az = 360.0f + *az;
+  }
+  ERROR_CHECK(skywatcher_get_motor_position(rot, 2, (float *) el));
+
+  rig_debug(RIG_DEBUG_TRACE, "%s: (az, el) = (%.1f, %.1f)\n", __func__, *az, *el);
+  return RIG_OK;
+}
+
+static int skywatcher_stop(ROT *rot) {
+  rig_debug(RIG_DEBUG_TRACE, "%s called\n", __func__);
+  char str[16];
+  // don't wait for actual stop. Operation can be async
+  ERROR_CHECK(skywatcher_cmd(rot, ":K1\r", str, sizeof(str)));
+  ERROR_CHECK(skywatcher_cmd(rot, ":K2\r", str, sizeof(str)));
+  return RIG_OK;
+}
+
+int skywatcher_set_motor_position(ROT *rot, int motor_index, float angle) {
+  char str[16];
+  char req[16];
+  hamlib_port_t *rotp = ROTPORT(rot);
+  SNPRINTF(req, sizeof(req), ":f%d\r", motor_index);
+  int current_retry = 0;
+  int stopped = 0;
+  while (current_retry < rotp->retry) {
+    ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+    int status = str[1] - '0';
+    if (status & 0b10) {
+      rig_debug(RIG_DEBUG_ERR, "%s: motor is blocked\n", __func__);
+      return RIG_EPROTO;
+    }
+    if (status & 0b1) {
+      current_retry++;
+      //10ms sleep just to make sure motor is fully stopped
+      hl_usleep(10000);
+      continue;
+    }
+    stopped = 1;
+    break;
+  }
+  if (!stopped) {
+    return RIG_EPROTO;
+  }
+  SNPRINTF(req, sizeof(req), ":G%d00\r", motor_index);
+  ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+  uint32_t cpr;
+  ERROR_CHECK(skywatcher_get_spr(rot, motor_index, &cpr));
+  double ticks_per_angle = (double) cpr / 360.0;
+  uint32_t value = ((uint32_t) (ticks_per_angle * angle)) & 0xFFFFFF;
+  value = value | 0x800000;
+  SNPRINTF(req, sizeof(req), ":S%d%02X%02X%02X\r", motor_index, (value & 0xFF), (value & 0xFF00) >> 8, (value & 0xFF0000) >> 16);
+  ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+  // start motion, don't wait until it completes
+  SNPRINTF(req, sizeof(req), ":J%d\r", motor_index);
+  ERROR_CHECK(skywatcher_cmd(rot, req, str, sizeof(str)));
+  return RIG_OK;
+}
+
+static int skywatcher_set_position(ROT *rot, azimuth_t az, elevation_t el) {
+  rig_debug(RIG_DEBUG_TRACE, "%s called: %f %f\n", __func__, az, el);
+  ERROR_CHECK(skywatcher_stop(rot));
+  // stop is called for 1 then for 2 motor. do motor position in reverse because it awaits "stop motor" state.
+  // potentially saving 1 call to :f
+  ERROR_CHECK(skywatcher_set_motor_position(rot, 2, el));
+  ERROR_CHECK(skywatcher_set_motor_position(rot, 1, az));
+  return RIG_OK;
+}
+
+static int skywatcher_init(ROT *rot) {
+  rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
+  skywatcher_priv_data *result = calloc(1, sizeof(skywatcher_priv_data));
+  if (result == NULL) {
+    return -RIG_ENOMEM;
+  }
+  memset(result->cpr, 0, sizeof(result->cpr));
+  ROTSTATE(rot)->priv = result;
+  return RIG_OK;
+}
+
+static int skywatcher_cleanup(ROT *rot) {
+  skywatcher_priv_data *priv = ROTSTATE(rot)->priv;
+  if (priv == NULL) {
+    return RIG_OK;
+  }
+  free(priv);
+  return RIG_OK;
+}
+
+/* ************************************************************************* */
+/*
+ * Protocol documentation:
+ *  https://inter-static.skywatcher.com/downloads/skywatcher_motor_controller_command_set.pdf
+ */
+const struct rot_caps skywatcher_rot_caps =
+    {
+        ROT_MODEL(ROT_MODEL_SKYWATCHER),
+        .model_name =     "Sky-Watcher",
+        .mfg_name =       "Sky-Watcher",
+        .version =        "20240825.0",
+        .copyright =      "LGPL",
+        .status =         RIG_STATUS_STABLE,
+        .rot_type =       ROT_TYPE_AZEL,
+        .port_type =      RIG_PORT_SERIAL,
+        .serial_rate_min  = 9600,
+        .serial_rate_max  = 9600,
+        .serial_data_bits = 8,
+        .serial_stop_bits = 1,
+        .serial_parity    = RIG_PARITY_NONE,
+        .serial_handshake = RIG_HANDSHAKE_NONE,
+        .write_delay      = 0,
+        .post_write_delay = 0,
+        .timeout          = 3500, /* worst case scenario */
+        .retry            = 1,
+
+        .min_az =     0.0f,
+        .max_az =     360.0f,
+        .min_el =     0.0f,
+        .max_el =     180.0f,
+
+        .rot_init     = skywatcher_init,
+        .rot_cleanup  = skywatcher_cleanup,
+        .get_position = skywatcher_get_position,
+        .set_position = skywatcher_set_position,
+        .stop         = skywatcher_stop,
+        .get_info     = skywatcher_get_info,
+    };
+
+
+DECLARE_INITROT_BACKEND(skywatcher) {
+  rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
+  rot_register(&skywatcher_rot_caps);
+  return RIG_OK;
+}

rotators/skywatcher/skywatcher.h

@@ -0,0 +1,26 @@
+/*
+ *  Hamlib Rotator backend - Celestron interface protocol
+ *
+ *   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
+ *
+ */
+#ifndef HAMLIB_SKYWATCHER_H
+#define HAMLIB_SKYWATCHER_H 1
+
+#include "rotator.h"
+
+extern const struct rot_caps skywatcher_rot_caps;
+
+#endif //HAMLIB_SKYWATCHER_H

src/rot_reg.c

@@ -93,6 +93,7 @@ DEFINE_INITROT_BACKEND(grbltrk);
 DEFINE_INITROT_BACKEND(flir);
 DEFINE_INITROT_BACKEND(apex);
 DEFINE_INITROT_BACKEND(saebrtrack);
+DEFINE_INITROT_BACKEND(skywatcher);
 
 //! @endcond
 
@@ -145,6 +146,7 @@ static struct
     { ROT_FLIR, ROT_BACKEND_FLIR, ROT_FUNCNAMA(flir) },
     { ROT_APEX, ROT_BACKEND_APEX, ROT_FUNCNAMA(apex) },
     { ROT_SAEBRTRACK, ROT_BACKEND_SAEBRTRACK, ROT_FUNCNAMA(saebrtrack)},
+    { ROT_SKYWATCHER, ROT_BACKEND_SKYWATCHER, ROT_FUNCNAMA(skywatcher)},
     { 0, NULL }, /* end */
 };
 
@@ -260,7 +262,7 @@ static int rot_lookup_backend(rot_model_t rot_model)
 {
     int i;
 
-    for (i = 0; i < ROT_BACKEND_MAX && rot_backend_list[i].be_name; i++)
+  for (i = 0; i < ROT_BACKEND_MAX && rot_backend_list[i].be_name; i++)
     {
         if (ROT_BACKEND_NUM(rot_model) ==
                 rot_backend_list[i].be_num)