Example of using Xbus library to communicate with an MTi-1 series device using a full-duplex UART connection.

Dependencies:   mbed-rtos mbed Xbus

Fork of MTi-1_example by Alex Young

Important Information

This example is deprecated and no longer maintained. There are new embedded examples available in the MT SDK folder of the MT Software Suite. For more information please visit: https://xsenstechnologies.force.com/knowledgebase/s/article/Introduction-to-the-MT-SDK-programming-examples-for-MTi-devices

Overview

The example program demonstrates connecting to an MTi-1 series device, restoring communications settings to default if necessary, and configuring the MTi to send data. For an MTi-1 the device is configured to send inertial sensor data, while MTi-2 and MTi-3 devices are configured to output orientation data using the onboard XKF3i filter.

Communication with the MTi-1 series device is implemented using a either a full-duplex UART, I2C or SPI bus. A reset line is used to reset the MTi during initialization. Data is output to a host PC terminal using a second UART.

For more information on the MTi-1 series communication protocol please refer to the datasheet: https://www.xsens.com/download/pdf/documentation/mti-1/mti-1-series_datasheet.pdf

Supported Platforms

The program has been tested on the following mbed platforms:

Using the Example

  1. To use the example program connect one of the supported mbed boards to the host PC and download the application from the mbed online compiler to the target device.
  2. With the mbed board unpowered (USB disconnected) wire the mbed board to the MTi-1 development board. The following connections are required:
    • In all cases:
      • 5V (or 3V3) main supply to VDD (P300-1)
      • MCU IO voltage (IORef) to VDDIO (P300-2)
      • GND to GND (P300-3)
      • MT_NRESET to nRST (P300-5)
    • For I2C communication:
      • MT_SCL to I2C_SCL (P300-9)
      • MT_SDA to I2C_SDA (P300-11)
      • MT_DRDY to DRDY (P300-15)
      • MT_ADD0 to ADD0 (P300-17)
      • MT_ADD1 to ADD1 (P300-19)
      • MT_ADD2 to ADD2 (P300-21)
    • For SPI communication:
      • MT_DRDY to DRDY (P300-15)
      • MT_SCLK to SPI_SCK (P300-17)
      • MT_MISO to SPI_MISO (P300-19)
      • MT_MOSI to SPI_MOSI (P300-21)
      • MT_nCS to SPI_nCS (P300-23)
    • For UART communication:
      • MT_RX to UART_TX (P300-9)
      • MT_TX to UART_RX (P300-11)

For more information on the MTi-1 development board please refer to the MTi-1 series user manual: https://www.xsens.com/download/pdf/documentation/mti-1/mti-1-series_dk_user_manual.pdf

Information

Check the defines at the top of main.cpp to determine which IO pins are used for the MT_xxx connections on each mbed platform.

Information

The active peripheral (I2C, SPI or UART) is selected on the MTi-1 development board through the PSEL0 and PSEL1 switches. Look on the bottom of the development board for the correct settings.

  1. Connect to the target using a serial terminal. The application is configured for:
    • Baudrate = 921600
    • Stop bits = 1
    • No parity bits
    • No flow control
  2. Reset the mbed board.
  3. You should be presented with a simple user interface as shown below:
MTi-1 series embedded example firmware.
Device ready for operation.
Found device with ID: 03880011.
Device is an MTi-3: Attitude Heading Reference System.
Output configuration set to:
        Packet counter: 65535 Hz
        Sample time fine: 65535 Hz
        Quaternion: 100 Hz
        Status word: 65535 Hz

Press 'm' to start measuring and 'c' to return to config mode.

Files at this revision

API Documentation at this revision

Comitter:
Alex Young
Date:
Thu May 21 16:30:21 2015 +0200
Parent:
45:67203918bec9
Child:
47:c4610a65dade
Commit message:
Add documentation for xbusparser

Changed in this revision

xbus/xbusparser.c Show annotated file Show diff for this revision Revisions of this file
xbus/xbusparser.h Show annotated file Show diff for this revision Revisions of this file
--- a/xbus/xbusparser.c	Thu May 21 16:14:14 2015 +0200
+++ b/xbus/xbusparser.c	Thu May 21 16:30:21 2015 +0200
@@ -19,6 +19,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+/*! \brief XbusParser states. */
 enum XbusParserState
 {
 	XBPS_Preamble,          /*!< \brief Looking for preamble. */
@@ -31,20 +32,39 @@
 	XBPS_Checksum           /*!< \brief Waiting for checksum. */
 };
 
+/*!
+ * \brief Xbus Parser state structure.
+ */
 struct XbusParser
 {
+	/*! \brief Callbacks for memory management, and message handling. */
 	struct XbusParserCallback callbacks;
+	/*! \brief Storage for the current message being received. */
 	struct XbusMessage currentMessage;
+	/*! \brief The number of bytes of payload received for the current message. */
 	uint16_t payloadReceived;
+	/*! \brief The calculated checksum for the current message. */
 	uint8_t checksum;
+	/*! \brief The state of the parser. */
 	enum XbusParserState state;
 };
 
+/*!
+ * \brief Get the amount of memory needed for the XbusParser structure.
+ */
 size_t XbusParser_mem(void)
 {
 	return sizeof(struct XbusParser);
 }
 
+/*!
+ * \brief Create a new XbusParser object.
+ * \param callback Pointer to callback structure containing callback functions
+ * for memory management and handling received messages.
+ * \returns Pointer the new XbusParser structure.
+ *
+ * Uses malloc to allocate the memory required for the parser.
+ */
 struct XbusParser* XbusParser_create(struct XbusParserCallback const* callback)
 {
 	void* mem = malloc(XbusParser_mem());
@@ -55,11 +75,22 @@
 	return NULL;
 }
 
+/*!
+ * \brief Frees an XbusParser structure allocated by XbusParser_create().
+ */
 void XbusParser_destroy(struct XbusParser* parser)
 {
 	free(parser);
 }
 
+/*!
+ * \brief Initializes an XbusParser in the passed memory location.
+ * \param parserMem Pointer to memory to use for storing parser state. Should
+ * be at least as big as the value returned by XbusParser_mem().
+ * \param callback Pointer to callback structure containing callback functions
+ * for memory management and handling received messages.
+ * \returns Initialized XbusParser structure.
+ */
 struct XbusParser* XbusParser_init(void* parserMem, struct XbusParserCallback const* callback)
 {
 	struct XbusParser* parser = (struct XbusParser*)parserMem;
@@ -70,6 +101,11 @@
 	return parser;
 }
 
+/*!
+ * \brief Parse a XMID_DeviceId message to extract the device ID value.
+
+ * Replaces the raw Xbus message data with the device ID.
+ */
 static void parseDeviceId(struct XbusParser* parser, uint8_t const* rawData)
 {
 	uint32_t* deviceId = parser->callbacks.allocateBuffer(sizeof(uint32_t));
@@ -85,6 +121,12 @@
 	}
 }
 
+/*!
+ * \brief Parse a XMID_OutputConfig message.
+ *
+ * Replaces the raw Xbus message data with an array of OutputConfiguration
+ * structures.
+ */
 static void parseOutputConfig(struct XbusParser* parser, uint8_t const* rawData)
 {
 	uint8_t fields = parser->currentMessage.length / 4;
@@ -107,6 +149,13 @@
 	}
 }
 
+/*!
+ * \brief Converts raw Xbus payload data to native structures if possible.
+ *
+ * Raw data payloads are converted to native data structures and the
+ * message data pointer is changed to point to the native structure.
+ * The raw data is automatically deallocated.
+ */
 static void parseMessagePayload(struct XbusParser* parser)
 {
 	uint8_t const* const rawData = parser->currentMessage.data;
@@ -129,12 +178,24 @@
 		parser->callbacks.deallocateBuffer(rawData);
 }
 
+/*!
+ * \brief Prepare for receiving a message payload.
+ *
+ * Requests a memory area to store the received data to using the
+ * registered callbacks.
+ */
 void prepareForPayload(struct XbusParser* parser)
 {
 	parser->payloadReceived = 0;
 	parser->currentMessage.data = parser->callbacks.allocateBuffer(parser->currentMessage.length);
 }
 
+/*!
+ * \brief Parse a byte of data from a motion tracker.
+ *
+ * When a complete message is received the user will be notified by a call
+ * to the handleMessage() callback function.
+ */
 void XbusParser_parseByte(struct XbusParser* parser, const uint8_t byte)
 {
 	switch (parser->state)
@@ -221,6 +282,9 @@
 	}
 }
 
+/*!
+ * \brief Parse a buffer of data received from a motion tracker.
+ */
 void XbusParser_parseBuffer(struct XbusParser* parser, uint8_t const* buf, size_t bufSize)
 {
 	for (size_t i = 0; i < bufSize; ++i)
--- a/xbus/xbusparser.h	Thu May 21 16:14:14 2015 +0200
+++ b/xbus/xbusparser.h	Thu May 21 16:30:21 2015 +0200
@@ -26,6 +26,9 @@
 
 struct XbusParser;
 
+/*!
+ * \brief Callback function structure for use with the XbusParser.
+ */
 struct XbusParserCallback
 {
 	/*!