Merge pull request #178 from fnoble/mookerji-omglolcatswftbbq

Example for the new TWEET message

Author: mookerji

c/include/libsbp/logging.h

@@ -47,6 +47,16 @@ typedef struct __attribute__((packed)) {
 #define SBP_MSG_DEBUG_VAR 0x0011
 
 
+/** Tweet
+ *
+* All the news fit to tweet.
+ */
+#define SBP_MSG_TWEET     0x0012
+typedef struct __attribute__((packed)) {
+  char tweet[140]; /**< Human-readable string */
+} msg_tweet_t;
+
+
 /** \} */
 
 #endif /* LIBSBP_LOGGING_MESSAGES_H */

python/sbp/client/examples/tweet.py

@@ -0,0 +1,64 @@
+# Copyright (C) 2015 Swift Navigation Inc.
+# Contact: Fergus Noble <[email protected]>
+#
+# This source is subject to the license found in the file 'LICENSE' which must
+# be be distributed together with this source. All other rights reserved.
+#
+# THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
+# EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
+
+"""
+the :mod:`sbp.client.examples.tweet` module contains a basic example of
+reading SBP messages from a serial port, decoding TWEET messages and pushing
+them to the twitter API.
+"""
+
+from sbp.client.drivers.pyserial_driver import PySerialDriver
+from sbp.client.handler import Handler
+from sbp.logging import SBP_MSG_TWEET, MsgTweet
+
+import time
+import twitter
+
+twit = None
+
+def tweet_callback(msg):
+  # This function is called every time we receive a TWEET message
+  if twit is not None:
+    twit.statuses.update(status=MsgTweet(msg).tweet)
+
+def main():
+
+  import argparse
+  parser = argparse.ArgumentParser(description="Swift Navigation Tweetxample.")
+  parser.add_argument("TOKEN")
+  parser.add_argument("TOKEN_KEY")
+  parser.add_argument("CON_SEC")
+  parser.add_argument("CON_SEC_KEY")
+  parser.add_argument("-p", "--port",
+                      default=['/dev/ttyUSB0'], nargs=1,
+                      help="specify the serial port to use.")
+  args = parser.parse_args()
+
+  my_auth = twitter.OAuth(args.TOKEN, args.TOKEN_KEY,
+                          args.CON_SEC, args.CON_SEC_KEY)
+  twit = twitter.Twitter(auth=my_auth)
+
+  # Open a connection to Piksi using the default baud rate (1Mbaud)
+  with PySerialDriver(args.port[0], baud=1000000) as driver:
+    # Create a handler to connect our Piksi driver to our callbacks
+    with Handler(driver.read, driver.write, verbose=True) as handler:
+      # Add a callback for BASELINE_NED messages
+      handler.add_callback(baseline_callback, msg_type=SBP_MSG_BASELINE_NED)
+
+      # Sleep until the user presses Ctrl-C
+      try:
+        while True:
+          time.sleep(0.1)
+      except KeyboardInterrupt:
+        pass
+
+if __name__ == "__main__":
+  main()
+

python/sbp/logging.py

@@ -126,8 +126,78 @@ def __repr__(self):
     return fmt_repr(self)
 
 
+SBP_MSG_TWEET = 0x0012
+class MsgTweet(SBP):
+  """SBP class for message MSG_TWEET (0x0012).
+
+  You can have MSG_TWEET inherent its fields directly
+  from an inherited SBP object, or construct it inline using a dict
+  of its fields.
+
+  
+  All the news fit to tweet.
+
+  Parameters
+  ----------
+  sbp : SBP
+    SBP parent object to inherit from.
+  tweet : string
+    Human-readable string
+  sender : int
+    Optional sender ID, defaults to 0
+
+  """
+  _parser = Struct("MsgTweet",
+                   String('tweet', 140),)
+
+  def __init__(self, sbp=None, **kwargs):
+    if sbp:
+      self.__dict__.update(sbp.__dict__)
+      self.from_binary(sbp.payload)
+    else:
+      super( MsgTweet, self).__init__()
+      self.msg_type = SBP_MSG_TWEET
+      self.sender = kwargs.pop('sender', 0)
+      self.tweet = kwargs.pop('tweet')
+
+  def __repr__(self):
+    return fmt_repr(self)
+ 
+  def from_binary(self, d):
+    """Given a binary payload d, update the appropriate payload fields of
+    the message.
+
+    """
+    p = MsgTweet._parser.parse(d)
+    self.__dict__.update(dict(p.viewitems()))
+
+  def to_binary(self):
+    """Produce a framed/packed SBP message.
+
+    """
+    c = containerize(exclude_fields(self))
+    self.payload = MsgTweet._parser.build(c)
+    return self.pack()
+
+  @staticmethod
+  def from_json(s):
+    """Given a JSON-encoded string s, build a message object.
+
+    """
+    d = json.loads(s)
+    sbp = SBP.from_json_dict(d)
+    return MsgTweet(sbp)
+
+  def to_json_dict(self):
+    self.to_binary()
+    d = super( MsgTweet, self).to_json_dict()
+    j = walk_json_dict(exclude_fields(self))
+    d.update(j)
+    return d
+    
 
 msg_classes = {
   0x0010: MsgPrint,
   0x0011: MsgDebugVar,
+  0x0012: MsgTweet,
 }

python/tests/sbp/test_table.py

@@ -34,7 +34,7 @@ def test_table_count():
   Test number of available messages to deserialize.
 
   """
-  number_of_messages = 53
+  number_of_messages = 54
   assert len(_SBP_TABLE) == number_of_messages
 
 def test_table_unqiue_count():

spec/yaml/swiftnav/sbp/logging.yaml

@@ -37,3 +37,14 @@ definitions:
     desc: |
       This is an unused legacy message for tracing variable values
       within the device firmware and streaming those back to the host.
+
+ - MSG_TWEET:
+    id: 0x0012
+    public: False
+    short_desc: Tweet
+    desc: All the news fit to tweet.
+    fields:
+      - tweet:
+          type: string
+          size: 140
+          desc: Human-readable string