The Java Carputer
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The document discusses building a "carputer" system using a Raspberry Pi to monitor and display real-time data from a vehicle. It describes connecting various sensors like an accelerometer, GPS, and thermal sensors to measure metrics like acceleration, location, and brake/tire temperatures. The system runs a JavaFX user interface on the Raspberry Pi touchscreen to display live data, graphs, and other screens. The document outlines the hardware architecture and provides code examples for reading sensor data and displaying it in the carputer system.
The Java Carputer
- 1. Carjacking With Java (Or Building A Java Carputer) Simon Ri>er Head of Java Evangelism, Oracle Twi>er: @speakjava Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 2. Safe Harbor Statement The following is intended to outline our general product direcRon. It is intended for informaRon purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or funcRonality, and should not be relied upon in making purchasing decisions. The development, release, and Rming of any features or funcRonality described for Oracle’s products remains at the sole discreRon of Oracle. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 2
- 3. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Program Agenda Cars And Computers The Java Carputer (Mark 1) The Java Carputer (Mark 2) Heads Up Display/TelemaRcs Data Recording/Analysis Conclusions, Resources and Demos 1 2 3 4 5 6
- 4. Cars And Computers Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 5. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. My First Car: 1981 1971 Mini Clubman 1000 • No electronics – Well, it had a radio • Purely electromechanical – Points/Distributor – Carbure>or/Manual choke – Drum brakes – Dynamo – Lights, horn, wipers, fan, igniRon switch
- 6. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Car Wiring: 1970s Image coutesy of Haynes manuals
- 7. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. My Current Car • Lots of electronics – Engine Control Unit (ECU) – Fuel InjecRon/Electronic Rming – “Fly-‐by-‐wire” thro>le – AnR-‐lock Braking System (ABS) – Electronic Stability Program (ESP) – Magnetorheological Suspension – Satellite navigaRon – Auto-‐sensing wipers and lights 2011 Audi S3
- 8. Bus architecture means substan>ally less wiring Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Car Wiring: 2011 Convenience Bus Infotainment Bus Powertrain Bus
- 9. The Java Carputer (Mark 1) Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 10. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Carputer Design ObjecRves • Display realRme data • Engine performance (Power, Torque, Load) • Driver data (Thro>le posiRon, steering angle, braking force, etc) • G-‐Forces on car • Graphed data for Rme-‐based analysis
- 11. Carputer Hardware Architecture USB WiFi Dongle Touch Screen Copyright © 2014, Oracle and/or its affiliates. All rights reserved. HDMI Accelerometer USB I2C 12V Car Converter ELM327 Car Service Port 5V USB
- 12. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. ELM327 Cheap way to hack your car • WiFi or Bluetooth connecRon to OBD-‐II • Fixed IP address, Ad-‐hoc networking • Need to configure Raspberry Pi – /etc/network/interfaces • AT style commands for control • Non-‐AT commands are assumed to be OBD-‐II – Simple request-‐response interacRon – Easy to write Java code to handle this
- 13. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Touchscreen Lots of things available on eBay • 2 DIN fiing size – Ideal for centre console • HDMI input – Specifically marketed for Raspberry Pi • USB connecRon for touch screen
- 14. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Touchscreen Hardware FiJng Challenges
- 15. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Accelerometer • Sparkfun breakout board MPU 9150 – 9 DoF sensor (accelerometer, gyroscope, compass) • CommunicaRons via I2C – Configure Raspberry Pi /etc/modules • i2c-‐bcm2708, i2c-‐dev • i2c-‐detect -‐y 1 to get address – Compass communicaRon is a bit more complicated • Second I2C bus
- 16. Accelerometer Code Using Pi4J Library on Java SE Embedded I2CBus bus = I2CFactory.getInstance(I2CBus.BUS_1); I2CDevice device = bus.getDevice(0x68); /* Start sensing */ device.write(0x6B, (byte)0b00000000); device.write(0x6C, (byte)0b00000000); /* Set configuration */ device.write(0x1B, (byte)0b00011000); // Gyroscope device.write(0x1C, (byte)0b00000100); // Accelerometer device.read(0x3B, accelData, 0, ACCEL_PACKET_SIZE); Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 17. CalculaRng Power And Torque Torque (Nm) = Mass x Wheel Radius x AcceleraRon (in G) Torque (lb/l) = Torque in Nm x 0.73756 Power (BHP) = Torque (lb/l) x engine RPM / 5252 Copyright © 2014, Oracle and/or its affiliates. All rights reserved. • Results will not have high accuracy – Values in red are not precise • Dynamometer is the only way to get accurate figures • InteresRng to see values v. manufacturers figures
- 18. Carputer Solware Architecture Copyright © 2014, Oracle and/or its affiliates. All rights reserved. • Screens based – Splash screen – Basic and advanced car data – G forces on car – Graphed results of different parameters • Simple UI – Can’t read numbers when driving • Touchscreen to switch screens – Repurpose exisRng car controls to change screen? Real>me Data
- 19. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Design Ideas Take Inspira>on From Others Renault Megane Sport
- 20. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Design Ideas Take Inspira>on From Others Tesla
- 21. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Design Ideas Take Inspira>on From Others Lamborghini Reveton
- 22. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Simple Data Display Control • Only uses 3 nodes – Polygon – Rectangle – Line – Labels are opRonal • Displays – Current value – Maximum value since start (resetable) • Simple to understand from a glance
- 23. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Screens Splash Screen
- 24. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Screens
- 25. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Screens
- 26. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. UI Screens
- 27. Graph Plots Of Thro>le PosiRon And Power Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 28. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. JavaFX Charts And Colours Can Only Be Changed Using CSS .axis { -‐fx-‐tick-‐label: #FFFFFF; } .axis-‐tick-‐mark { -‐fx-‐stroke: #FFFFFF; } .axis-‐minor-‐tick-‐mark { -‐fx-‐stroke: #000000; } .chart-‐plot-‐background { -‐fx-‐background-‐color: #000000; } .chart-‐alternative-‐row-‐fill { -‐fx-‐fill: #000000; } .default-‐color0.chart-‐series-‐line { -‐fx-‐stroke: #FFFF33; }
- 29. The Java Carputer (Mark 2) Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 30. Carputer Hardware Architecture Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 30 Crossover ethernet USB via FTDI Infra red Thermal sensor CAN High CAN Low OBD2 Service Port Wi-‐Fi Accelerometer/ Gyro/Compass I2C USB UART Serial Heart Rate Monitor GPS USB Video Camera Raspberry Pi Model B+ 7” Touch secreen USB CAN Bus SDR/TPMS
- 31. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Tracking PosiRon With GPS • AdaFruit UlRmate GPS breakout – 10Hz read rate – Serial interface • Very simple configuraRon – Disable /dev/ttyAMA0 on Pi as console – 9600 8N1 – Read data using librxtx-‐java – Comma separated values $GPGGA and $GPVTG – Need to handle frequent data corrupRon
- 32. Heart Rate Monitoring of the Driver • Sparkfun Copyright © 2014, Oracle and/or its affiliates. All rights reserved. board – USB interface, serial connecRon • Similar to GPS – Use librxtx-‐java – 9600, 8N1 • More complicated coding – Actually need to send a read request! • Some issues with wireless connecRon – 80cm max, doesn’t work well through a Rapsberry Pi
- 33. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. In-‐car Video • Becoming very common to avoid insurance issues • Transcend DrivePro 200 – Built-‐in Wi-‐Fi – iPhone app • How to get video stream? – Approached Transcend tech support – Found VLC code – Wireshark – SYN/ACK, Yuck! 33 Camera Applica>on 192.168.0.1 192.168.0.2 Port 9000 Port 43229 Port 9001 Port 42719 Port 9002 Port 58105 Port 8554 (RTSP) Port 60583
- 34. The Simplest SoluRon Is Olen The Best Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 34 Push bu>on using GPIO lines and Pi4J
- 35. Thermal Sensors For Brakes and Tyres The Goal Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 36. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Infra-‐Red Thermometer • MLX90614 breakout board – I2C interface seemed problemaRc on the Pi – Also has serial interface – Use FTDI breakout board – 4 wires becomes simple serial interface 36 The Reality
- 37. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Thermal Sensor Data • Provides conRnuous reading as lines of text (e.g. 73.2F) – Don’t like Fahrenheit, wanted Celcius – Lambdas and Streams! 37 private double currentTemperature; public void run() { thermalReader.lines() .mapToDouble(s -‐> Double.parseDouble(s.substring(0, s.length() -‐ 1))) .map(t -‐> ((t -‐ 32) * 5 / 9)) .filter(t -‐> t != currentTemperature) .peek(t -‐> listener.ifPresent(l -‐> l.temperatureChange(t))) .forEach(t -‐> currentTemperature = t); }
- 38. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Thermal Sensor Data • Provides conRnuous reading as lines of text (e.g. 73.2F) – Don’t like Fahrenheit, wanted Celcius – Lambdas and Streams! 38 private double currentTemperature; public void run() { thermalReader.lines() .mapToDouble(s -‐> Double.parseDouble(s.substring(0, s.length() -‐ 1))) .map(t -‐> ((t -‐ 32) * 5 / 9)) .filter(t -‐> t != this.currentTemperature) .peek(t -‐> listener.ifPresent(l -‐> l.temperatureChange(t))) .forEach(t -‐> this.currentTemperature = t); }
- 39. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 39 Fiing The Thermal Sensors Tyre Sensor
- 40. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 40 Fiing The Thermal Sensors Brake Disk Sensor
- 41. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 41 Fiing The Thermal Sensors Separate Pi in Engine Bay
- 42. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Fiing The Thermal Sensors • Simple server listens on port • Carputer requests data • Couple of issues – Server needed reset for new connecRon (bug to be fixed) – How to tell which sensor is which (>yUSB0/>yUSB1) 42 The Networked Car
- 43. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Fiing The Thermal Sensors • Rasperry Pi at over 50C – Aler 10 minute drive • New approach required – Longer USB cables – Put the Pi in the car 43 Internal Combus>on Produces Heat
- 44. Geing Data From The CAN Bus • Controller Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Area Network • Used to connect many sensors, actuators and devices – Without huge amounts of wiring • Conveniently the CAN bus is connected to the OBD2 port – Yes, the wiring is there – No, the signals are not – Presumably security measure from car manufacturers – Boo!
- 45. Geing Data From The CAN Bus Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Where There’s A Will There’s A Way
- 46. Geing Data From The CAN Bus Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Where There’s A Will There’s A Way Success! (And the car sRll works)
- 47. Geing Data From The CAN Bus Copyright © 2014, Oracle and/or its affiliates. All rights reserved. • Lawicel CAN bus to USB • Serial device • Sends decoded data • Need to write a Java library – CAN id – Message data • Then the hard part starts – Figuring it all out 47 Electrical Connec>vity Is Only The Start
- 48. Finished Data Capture System Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 48
- 49. Heads Up Display/ TelemaRcs Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 50. In Car Heads Up Displays Are Becoming A Reality Jaguar Copyright © 2014, Oracle and/or its affiliates. All rights reserved. ConRnental Virtual Windscreen Mini Cooper NavTy
- 51. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Build Your Own HUD • Turns out it’s not that simple • First iteraRon – 3M MPro110 Micro Projector, half silvered film (from a cheap in-‐car HUD) • Didn’t really work – Too much reflecRon of projector lamp, not image
- 52. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. 52 Build Your Own HUD Second AWempt
- 53. Raspberry Pi Heads Up Display • Cheap Copyright © 2014, Oracle and/or its affiliates. All rights reserved. screen for the Pi • Use teleprompter glass rather than half-‐silvered perspex – 70% transmission, 30% refecRon much be>er • Issue: How to produce an inverted image? • Answer: Use a refecRon effect 53 Reflection ref = new Reflection(); ref.setFraction(1.0); ref.setBottomOpacity(1.0); ref.setTopOpacity(1.0);
- 54. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Data Display On HUD • Speed and engine RPM – Use OBD2 data – Wi-‐Fi dongle to access ELM327 • Convert posiRon (from GPS) into current speed limit – Bluetooth dongle for pairing with mobile phone – Configure Linux to provide network access via TCP/IP – Transmit posiRon obtained from GPS – Write servlet to run on home Linux box (open port on firewall) – Servlet uses posiRon and Ordanance Survey data to determine speed limit – (Future project) 54
- 55. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Hardware In Place 55
- 56. Data Recording and Analysis Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 57. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Display Collected Data • JavaFX applicaRon • Video stream – Synchronised to data streams • Data recorded as sequence of text records – Comma separated values – One line per sensor – Time stamp • Read all data in at start of applicaRon – 15 minutes of data takes about 100ms 57
- 58. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. • Video (with controls) • G-‐forces • GPS co-‐ordinates/alRtude • Map of current posiRon • Speed (compare car and GPS) • Bearing • Engine load • Fuel pressure • Air intake temperature • Coolant temperature • Catalyst/exhaust temperature • Tyre temperature • Brake temperature • Thro>le posiRon • Engine RPM • Heart rate 58 Data To Display
- 59. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. User Interface Design • Use JFXtras library (Gerrit Grunwald’s dials and LEDs) • Formula 1 style – Thro>le/brake/engine/gear display – LED tachometer • Heart rate number is not too exciRng – AnimaRons – ConRnuous pulses was a bit of a challenge (several parallel, offset transiRons) 59 JavaFX
- 60. Conclusions & Resources Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 61. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Conclusions • Cars produce lots of data • Use of sensors with Java is simple to collect (most) data • Playback of data useful for insurance, fleet management, training • Java and JavaFX make UI design simple
- 62. Copyright © 2014, Oracle and/or its affiliates. All rights reserved. Resources and Links • www.sparkfun.com • www.adafruit.com • www.raspberrypi.org • blogs.oracle.com/speakjava • Twi>er: @speakjava
- 63. Demos Copyright © 2014, Oracle and/or its affiliates. All rights reserved.
- 64. Carjacking With Java (Or Building A Java Carputer) Simon Ri>er Head of Java Evangelism, Oracle Twi>er: @speakjava Copyright © 2014, Oracle and/or its affiliates. All rights reserved.