motan: Add support for analyzing "angle" sensor data

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

scripts/motan/data_logger.py

@@ -157,6 +157,10 @@ class DataLogger:
                 aname = cfgname.split()[-1]
                 self.send_subscribe("adxl345:" + aname, "adxl345/dump_adxl345",
                                     {"sensor": aname})
+            if cfgname.startswith("angle "):
+                aname = cfgname.split()[1]
+                self.send_subscribe("angle:" + aname, "angle/dump_angle",
+                                    {"sensor": aname})
     def handle_dump(self, msg, raw_msg):
         msg_id = msg["id"]
         if "result" not in msg:

scripts/motan/readlog.py

@@ -374,6 +374,67 @@ class HandleADXL345:
             self.data_pos += 1
 LogHandlers["adxl345"] = HandleADXL345
 
+# Extract positions from magnetic angle sensor
+class HandleAngle:
+    SubscriptionIdParts = 2
+    ParametersMin = ParametersMax = 1
+    DataSets = [
+        ('angle(<name>)', 'Angle sensor position'),
+    ]
+    def __init__(self, lmanager, name, name_parts):
+        self.name = name
+        self.angle_name = name_parts[1]
+        self.jdispatch = lmanager.get_jdispatch()
+        self.next_angle_time = self.last_angle_time = 0.
+        self.next_angle = self.last_angle = 0.
+        self.cur_data = []
+        self.data_pos = 0
+        self.position_offset = 0.
+        self.angle_dist = 1.
+        # Determine angle distance from associated stepper's rotation_distance
+        config = lmanager.get_initial_status()['configfile']['settings']
+        aname = 'angle %s' % (self.angle_name,)
+        stepper_name = config.get(aname, {}).get('stepper')
+        if stepper_name is not None:
+            sconfig = config.get(stepper_name, {})
+            rotation_distance = sconfig.get('rotation_distance', 1.)
+            gear_ratio = sconfig.get('gear_ratio', ())
+            if type(gear_ratio) == str: # XXX
+                gear_ratio = [[float(v.strip()) for v in gr.split(':')]
+                              for gr in gear_ratio.split(',')]
+            for n, d in gear_ratio:
+                rotation_distance *= d / n
+            self.angle_dist = rotation_distance / 65536.
+    def get_label(self):
+        label = '%s position' % (self.angle_name,)
+        return {'label': label, 'units': 'Position\n(mm)'}
+    def pull_data(self, req_time):
+        while 1:
+            if req_time <= self.next_angle_time:
+                pdiff = self.next_angle - self.last_angle
+                tdiff = self.next_angle_time - self.last_angle_time
+                rtdiff = req_time - self.last_angle_time
+                po = rtdiff * pdiff / tdiff
+                return ((self.last_angle + po) * self.angle_dist
+                        + self.position_offset)
+            if self.data_pos >= len(self.cur_data):
+                # Read next data block
+                jmsg = self.jdispatch.pull_msg(req_time, self.name)
+                if jmsg is None:
+                    return (self.next_angle * self.angle_dist
+                            + self.position_offset)
+                self.cur_data = jmsg['data']
+                position_offset = jmsg.get('position_offset')
+                if position_offset is not None:
+                    self.position_offset = position_offset
+                self.data_pos = 0
+                continue
+            self.last_angle = self.next_angle
+            self.last_angle_time = self.next_angle_time
+            self.next_angle_time, self.next_angle = self.cur_data[self.data_pos]
+            self.data_pos += 1
+LogHandlers["angle"] = HandleAngle
+
 
 ######################################################################
 # Log reading