Difference between revisions of "F17: FoxP2"

Revision as of 12:13, 17 December 2017

Grading Criteria

FOXP2

Abstract

This project entails the aggregated knowledge from the Embedded System courses offered at SJSU leveraged into a fully functioning self-driving vehicle. This vehicle will navigate the terrain, avoid obstacles, and relay feedback to the user. The Initialization is enabled using the custom application which will set the final destination using GPS and destination node.

Objectives & Introduction

Show list of your objectives. This section includes the high-level details of your project. You can write about the various sensors or peripherals you used to get your project completed.

Team Members & Responsibilities

• R Nikfar
  • Team Lead
  • Electrical Circuits Engineering
  • PCB design
  • Sensor testing and implementation.

• Jason Tran
  • Sensor IO Implementaion, and testing
  • Master controller.

• Ahsan Uddin
  • Git Admin
  • Motor Control.

• Yuyu Chen
  • Geographical Implementation
  • Bridge Support

• Marvin Flores
  • Android Application development
  • Bridge Implementation

• Rabeel Elahi
  • Master Controller Implementation.

• Sophia Quan
  • LCD interface
  • Motor Control.

• Michael Jaradah
  • Testing.

• Taylor Kearns
  • Testing.

• Bohan Liu
  • Master Controller.

Schedule

Show a simple table or figures that show your scheduled as planned before you started working on the project. Then in another table column, write down the actual schedule so that readers can see the planned vs. actual goals. The point of the schedule is for readers to assess how to pace themselves if they are doing a similar project.

Parts List & Cost

Overall Design and Methodology

Eagle Schematic

Eagle Board

Board Connection Architecture

Our team's approach to the design of this project was solely based on the integrity of its connections and communication between the nodes. Each node would handle specific parts of the car that would require an extensive amount of computing. At the center of this communication would be our design and printed PCB(printed circuit board). This board was designed in a manner that would reduce the amount of noise within the circuitry of its components, and place its nodes at an optimal location relative to the car.

Insert Picture of the board connections here

Printed Circuit Board

The PCB which is at the heart of this project was designed in Eagle CAD. There were 2 iterations of this board. The first one was designed without validation and had problems with noise within the CAN communications(discussed in problems encountered section). This design lacked several necessary connections and was limited by functionality.

The Second version of the board would incorporate 4 external power outlets that supply 3.3V and 5V to external components as necessary. There would also be an external power unit with regulators that make sure that a clean power is fed to the boards if necessary. As shown in the schematic, the can transceivers are connected to the boards using the terminating resistors. This CAN bus line also connects to the DB9 connections to easily read the CAN data using the PCAN Dongle.

Before the Board was sent for printing, the rat nests had to be removed and the connections had to be routed in such a way that minimum amount of noise was created. this ensured a robust communication for the CAN bus and stable noise-free power supply for the external components such as the Ultrasonic Sensors.

Motor Controller

Motor Controller primary tasks are as follows: 1. Control the rear wheels for moving forward, backward and stop 2. Control the front wheels to maneuver 3. Display contents on the LCD

Hardware Design

1. ESC

2. Servo

3. RPM Sensor

4. LCD

Hardware Interface

1. CAN bus

2. PWM to Motor and servo

3. RPM sensor for edge detection

4. UART to LCD

In this section, you can describe how your hardware communicates, such as which BUSes used. You can discuss your driver implementation here, such that the Software Design section is isolated to talk about high level workings rather than inner working of your project.

Software Design

1. Init

2. 1 Hz Task

3. 10 Hz task

4. 100 Hz task

Show your software design. For example, if you are designing an MP3 Player, show the tasks that you are using, and what they are doing at a high level. Do not show the details of the code. For example, do not show exact code, but you may show psuedocode and fragments of code. Keep in mind that you are showing DESIGN of your software, not the inner workings of it.

Implementation

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

LCD

The uLCD-32PTU is a 3.2" (240x320) LCD screen with a micro SD connector, GPIO's along with I2C and serial COMMS. Workshop4 IDE was used to program the GUI, and data was transmitted from the SJOne board through UART communication. The LCD displays RPM clicks, GPS heading, bearing, distance, and also the current firmware version and branch name.

LCD Hardware Architecture

LCD Display

Note: The display here shows the angularmeter which will display the rpm, the top right box will display the bearing, heading, and distance from the GPS, and the bottom box will disply the firmware git hash, and branch.

Sensors

The primary responsibility of the sensor ECU is to provide object detection capabilities.

Hardware Design

For object detection, distance sensors are used to provide proximity awareness. 3 distance sensors are placed on the front of the car (front left, front, and front right) to continuously measure the distance of the general directions. An object or obstacle can be detected when the distance of a given direction is below a threshold which indicates that the car cannot traverse in that direction and should attempt steer away from the blocked path.

Hardware Interface

Sensor Hardware Architecture and Interface

Note: Despite the names, the TX and RX pins do not function as asynchronous serial transmit and receive. The TX functions as an open-drain output that pulls the line down when the sensor wants to trigger a cascaded sensor. The RX functions as an digital input that acts as a trigger for the sensor to begin measuring a distance.

Software Design

The sensor software follows a modular design pattern. Sensors is the top level module

Sensor Software Architecture

Implementation

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

Geographical Controller

The main purpose of the geographical controller is to guide the car towards its destination. This is done by processing data from the GPS and Compass module in order to get the Heading, Bearing, and Distance.
The compass will allow the user to calculate the Heading, which tells us which direction the car is pointing relative to magnetic north nor simply, "Which way the car is pointing"?
The GPS will allow the user to get the current coordinate of the car, which will be useful when calculating the Bearing and Distance.
The Bearing tells us the direction from the current location to a checkpoint coordinate, and is given as the angle between the location and the current location of the car.
The Distance tells us how many meters away the current checkpoint is. Essentially, How far away are we from our destination?

The geographical controller is also responsible for:
1. Process data from GPS and Compass module.
2. Navigate to nearest checkpoints and to set destination.
3. Receive checkpoints from Bridge controller.

Hardware Design

Hardware Interface

CAN Bus
The CAN bus interface allows the geographical controller to send and receive data from other microcontrollers on the bus. For example, the geographical controller will send requests to the Gateway controller to tell it to turn right, left, or keep straight in order to reach the set checkpoints. The geographical controller will receive checkpoints from the Bridge controller in order for the geographical controller to know how to steer or how far away the destination is at.

MTK3339 Ultimate GPS

The MTK3339 Ultimate GPS module from Adafruit was chosen because it provided good results when it was used previously for a different project. The main purpose of the GPS module is to provide an accurate location of the car while the car navigates towards its destination. This is done by parsing NMEA sentences, which are transmitted by 22 satellites to pinpoint the current location of the module. There are various different types of NMEA sentences, such as $GPRMC and $GPGGA. The NMEA sentence that was used was $GPRMC, which provides only the recommended minimum. $GPRMC was also chosen because it is the only NMEA sentence the GPS module is able to provide data at 10Hz for real-time application. The module is interfaced via UART with a baud-rate set to 57600bps. The module also comes with a fix LED, which indicates if a GPS fix by blinking every 15 seconds, if not, it blinks every 1Hz. The module is powered by 3.3V from the SJOne board.

The $GPRMC sentence is separated by commas, which the user has to parse in order to get useful data out of the module. The most important data that the user want is the GPS coordinate, Latitude and Longitude. The strtok_r() function was used in order to parse the NMEA sentence.
Below is an example of a parsed $GPRMC sentence:

      Example: $GPRMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68
                       1     2    3    4    5     6    7    8      9     10  11 12

CMPS11 - Tilt Compensated Compass Module
The CMPS11 - Tilt Compensated Compass module was chosen because it provides the heading value, which let the user know which way the car is facing relative to magnetic north. Not only does it provide heading, the module also has a 3-axis gyro and a 3-axis accelerometer to remove or neglect any errors while the module is tilted (going up or down a slope). Another compass module was considered before choosing this module because the old module had to be calibrated extensively in order for it to work properly. This module only needed to be calibrated one time in an environment free of magnetic interference. The heading was double-checked after the module was mounted onto the car.
The compass module is placed away from all other components of the car to minimize any magnetic interference from the motor, servo, sensors, and microcontrollers. Placing it in an environment where there is magnetic interference will cause incorrect reading of the heading and the car will navigate towards the wrong direction. The compass module is interfaced via I2C. It is powered on by 3.6-5V, but 3.3V works also.

Software Design

The Geographical Controller is designed in a way so that the code is modular and organized. Only what is needed are exposed.

           GPS                                                 Compass                                                                Geo_Sensor
bool gps_init(gps_data_ready_cb cb);                  bool cmps11_init(void);                                                   bool geo_sensor_init(void);
bool get_lat_long(float *gps_data);                   float cmps11_get_heading(void);                                           void geo_sensor_run(void);
                                                      bool cmps11_calibrate(bool start_calibration, bool end_calibration);      float compute_distance(float gps_lat, float gps_long, float dst_lat, float dst_long);

The GPS library and Compass library are used by Geo_Sensor in order to calculate the Heading, Bearing, and Distance when geo_sensor_run() is called. Extern variables are used to share data CAN layer and Geo_Sensor.

extern float e_heading;
extern float e_bearing;
extern float e_distance;
extern float e_curr_latitude;
extern float e_curr_longitude;
extern float e_checkpoint_latitude;
extern float e_checkpoint_longitude;
extern uint8_t e_heading_valid;
extern bool e_gps_distance_valid;

Implementation

geo bridge state machine

checkpoint, destination algorithm

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

Android Application

Main Tasks

• Generate checkpoints
• Send START and STOP commands
• Auto-connect to the Bridge module
• Display relevant information:
  • map
  • current phone location
  • current car location
  • connection heartbeat
  • checkpoint

Software Design

High Level Architecture Design

Android Application High Level Architecture Diagram

The application's high level design is simple: Use Google Maps API to get the checkpoints and forward them to the bridge controller. Once the checkpoints are sent, the START command can be executed by clicking the START button on the app. This sends a start command signal to the bridge controller which then forwards the message to the Geo Controller via CAN bus. The STOP command, however, can be executed at any point in time and has the same process as the START command.

Implementation

Android Architecture Diagram

Android applications follows the MVC pattern by default to allow developers to manage their applications easily. For this application, the Views are the MapView, Buttons, Heartbeat (ImageView), and TextViews to display extra information from the bridge. The Controller is the main fragment that contains all the logic. The Models are the data that come from the the Google Maps API and data coming from the bridge.

The MapPane Fragment is used as the main view of the application. MapPane Fragment contains the MapView, buttons for CHECKPOINTS, START, and STOP, as well as some extra information from the Bridge Controller such as heartbeat and sensor values.

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

SCons - Build Automation

SCons is a build automation tool similar to Make and is based on the Python programming language. The 2 documents below describe the basic usage of SCons to build firmware and unit tests.

File:Cmpe243 f17 foxp2 SCons Build Automation.docx

File:Cmpe243 f17 foxp2 SCons Building Unit Tests.docx

There are 3 build environments defined for the FoxP2 project.

1. ARM build environment

2. DBC build environment

3. Unit test build environment

ARM Build Environment

The ARM build environment utilizes the GNU ARM embedded toolchain to compile code for ARM targets namely for the SJOne Board's LPC1758 powered by an ARM Cortex-M3 (ARMv7-M architecture). Resources used by this build environment include Cortex-M3 specific code, FreeRTOS, start up code, linker scripts, LPC1758 drivers, and finally application-specific code. To build an ECU-specific program, an ECU name can be provided as a command line argument.

DBC Build Environment

The DBC build environment utilizes the default Python interpreter (defined in PATH) and the DBC parser Python tool to generate a C header file. The build environment uses the target ECU name as the target NODE required by the DBC parser.

Unit Test Build Environment

The unit test build environment utilizes the native C compiler on Linux hosts and Cygwin's C compiler on Windows hosts. SCons automatically searches for all unit tests source files in a test directory with file names starting with "test_". When the unit test flag is provided on command line, SCons will build then executed all unit tests. If any unit test fails, the overall SCons build will fail. For Windows, the FoxP2 repository contains pre-built shared libraries (.dll) of Cgreen unit testing library and Cygwin's POSIX references which are linked at run-time.

Validation and Testing Plan

Sensor Testing:

• • Front left sensor detection (values)
  • Front right sensor detection (values)
  • Front middle sensor detection (values)
  • Back left sensor detection (values)
  • Back right sensor detection (values)
  • Response & accuracy / precision
    • put object 1 ft away, and make sure it reads 12 in (inches are sent over can)
    • response to approaching obstacles (start from 3ft away and move in)
    • LED correspondence with values
  • All sensor MIA handling

Object Avoidance Testing:

• • If right sensor blocked, go left
  • If left sensor blocked, go right
  • If front sensor blocked, reverse, go right/left
  • If right & left sensor blocked, reverse, go right/left
  • If back sensor blocked, move forward
  • If back and front left blocked, go right
  • If back and front right blocked, go left

Motor Testing:

• • If ramped up, speed up
  • If ramped down, slow down
  • If no ramp, constant speed

LCD Testing:

• • Display compass
  • Display voltage
  • Display speed
  • Githash version
  • Branch name
  • All values update accordingly
  • Display values MIA handling

Voltage sensor Testing:

• • Compare smart device, voltmeter, and sensor readings

App Testing:

• • Automatic car connection
  • Set a GPS location
  • Sends stop to car until destination chosen
  • MIA car / GPS lock handling

Geographical testing:

• • Losing the GPS Lock
  • Accuracy in sending coordinates
  • Location accuracy in chosing destination
  • MIA GPS sensor

Basic Hardware Testing:

• • Confirm switch to turn on car works
  • 7-Seg value indication
  • LED indications
  • No loose / flimsy wires
  • Car doesn't move unless given a GPS coordinate
  • Avoids obstacles while moving towards a target destination
  • Can reverse away from obstacles and continue towards the destination
  • Avoid GPS when reversing for 5 seconds

Testing & Technical Challenges

Describe the challenges of your project. What advise would you give yourself or someone else if your project can be started from scratch again? Make a smooth transition to testing section and described what it took to test your project.

Include sub-sections that list out a problem and solution, such as:

<Bug/issue name>

Discuss the issue and resolution.

Conclusion

Conclude your project here. You can recap your testing and problems. You should address the "so what" part here to indicate what you ultimately learnt from this project. How has this project increased your knowledge?

Project Video

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Project Source Code

References

Acknowledgement

Any acknowledgement that you may wish to provide can be included here.

References Used

List any references used in project.

Appendix

You can list the references you used.