From c0b510d80410b411541afc497ecbf2097259ea6b Mon Sep 17 00:00:00 2001
From: Nate Bargmann <n0nb@n0nb.us>
Date: Mon, 15 Sep 2014 05:45:45 -0500
Subject: [PATCH] Implement precision set_position for RT-21

The RT-21 will accept the command 'AP1XXX.Y<CR>;' which allows settings
to 1/10 of a degree.  XXX must be zero padded.  '<CR>' causes the RT-21
to rotate to the position immediately with out the need for a following
'AM1;' command.

Tested by Will, WC2L.
---
 rotorez/rotorez.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/rotorez/rotorez.c b/rotorez/rotorez.c
index 37ab6e6de..51766948e 100644
--- a/rotorez/rotorez.c
+++ b/rotorez/rotorez.c
@@ -61,6 +61,7 @@ static int rotorez_rot_set_position(ROT *rot, azimuth_t azimuth, elevation_t ele
 static int rotorez_rot_get_position(ROT *rot, azimuth_t *azimuth, elevation_t *elevation);
 static int erc_rot_get_position(ROT *rot, azimuth_t *azimuth, elevation_t *elevation);
 static int rt21_rot_get_position(ROT *rot, azimuth_t *azimuth, elevation_t *elevation);
+static int rt21_rot_set_position(ROT *rot, azimuth_t azimuth, elevation_t elevation);
 
 static int rotorez_rot_reset(ROT *rot, rot_reset_t reset);
 static int rotorez_rot_stop(ROT *rot);
@@ -292,7 +293,7 @@ const struct rot_caps rt21_rot_caps = {
 	.rot_model =		ROT_MODEL_RT21,
 	.model_name =		"RT-21",
 	.mfg_name =		"Green Heron",
-	.version =		"2014-09-12a",
+	.version =		"2014-09-14",
 	.copyright =		"LGPL",
 	.status =		RIG_STATUS_ALPHA,
 	.rot_type =		ROT_TYPE_OTHER,
@@ -318,7 +319,7 @@ const struct rot_caps rt21_rot_caps = {
 
 	.rot_init =		rotorez_rot_init,
 	.rot_cleanup =		rotorez_rot_cleanup,
-	.set_position =		rotorez_rot_set_position,
+	.set_position =		rt21_rot_set_position,
 	.get_position =		rt21_rot_get_position,
 //	.stop =				rotorez_rot_stop,
 //	.set_conf =			rotorez_rot_set_conf,
@@ -415,6 +416,35 @@ static int rotorez_rot_set_position(ROT *rot, azimuth_t azimuth, elevation_t ele
 }
 
 
+/*
+ * RT-21 Set position.
+ *
+ * RT-21 has a custom command to set azimuth to a precision of 1/10 of a
+ * degree--"AP1XXX.Y\r;".  XXX must be zero padded.  The '\r' causes the
+ * command to be executed immediately (no need to send "AM1;").
+ */
+
+static int rt21_rot_set_position(ROT *rot, azimuth_t azimuth, elevation_t elevation) {
+	char cmdstr[16];
+	int err;
+
+	rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
+
+	if (!rot)
+		return -RIG_EINVAL;
+
+	if (azimuth < 0 || azimuth > 360)
+		return -RIG_EINVAL;
+
+	sprintf(cmdstr, "AP1%05.1f\r;", azimuth);	/* Total field width of 5 chars */
+	err = rotorez_send_priv_cmd(rot, cmdstr);
+	if (err != RIG_OK)
+		return err;
+
+	return RIG_OK;
+}
+
+
 /*
  * Get position
  * Returns current azimuth position in whole degrees.