AP_Scripting: add mavlink test

libraries/AP_Scripting/tests/mavlink_test.lua

@@ -0,0 +1,37 @@
+mavlink_msgs = require("mavlink/mavlink_msgs")
+
+msg_map = {}
+
+heartbeat_msgid = mavlink_msgs.get_msgid("HEARTBEAT")
+
+msg_map[heartbeat_msgid] = "HEARTBEAT"
+-- initialise mavlink rx with number of messages, and buffer depth
+mavlink.init(1, 10)
+-- register message id to receive
+mavlink.receive_msgid(heartbeat_msgid)
+test_named_value = 0.0
+function str_to_bytes(str)
+    str_len = string.len(str)
+    bytes =  {}
+    for i = 1, str_len do
+        bytes[i] = string.byte(str, i)
+    end
+    return bytes
+end
+function update()
+    local msg = mavlink.receive()
+    if msg then
+        parsed_msg = mavlink_msgs.decode(msg, msg_map)
+        if parsed_msg.msgid == heartbeat_msgid then
+            gcs:send_text(6, string.format("Received heartbeat from %d", parsed_msg.sysid))
+        end
+    else
+        gcs:send_text(6, "No heartbeat received")
+    end
+    test_named_value = test_named_value + 1.0
+    -- send named value float
+    mavlink.send(0, mavlink_msgs.encode("NAMED_VALUE_FLOAT", {time_boot_ms = millis():toint(), name = str_to_bytes("test"), value = test_named_value}))
+    return update, 1000
+end
+
+return update()