Project from Real-Time Systems – Lego Mindstorms EV3 April 5, 2018 Lego Mindstorms EV3 Lego Mindstorms • manufactured by LEGO, http://mindstorms.lego.com • extension of LEGO Technic line • history: • RCX, 1998 • NXT, 2006; NXT 2.0, 2009 • EV3, 2013 • why LEGO? Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments • 16MB FLASH memory, 64 MB RAM (cf. 64 kB flash in NXT!), microSDHC slot (up to 32 GB) Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments • 16MB FLASH memory, 64 MB RAM (cf. 64 kB flash in NXT!), microSDHC slot (up to 32 GB) • runs a native version of Linux Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments • 16MB FLASH memory, 64 MB RAM (cf. 64 kB flash in NXT!), microSDHC slot (up to 32 GB) • runs a native version of Linux • USB host port, mini USB port, Bluetooth interface (Android and iOS connectivity and apps available) Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments • 16MB FLASH memory, 64 MB RAM (cf. 64 kB flash in NXT!), microSDHC slot (up to 32 GB) • runs a native version of Linux • USB host port, mini USB port, Bluetooth interface (Android and iOS connectivity and apps available) • 4 and 4 output ports, connection via modified RJ12 cables Lego Mindstorms EV3 EV3 Brick • 300 MHz 32-bit ARM9 microcontroller by Texas Instruments • 16MB FLASH memory, 64 MB RAM (cf. 64 kB flash in NXT!), microSDHC slot (up to 32 GB) • runs a native version of Linux • USB host port, mini USB port, Bluetooth interface (Android and iOS connectivity and apps available) • 4 and 4 output ports, connection via modified RJ12 cables • loudspeaker • buttons, display, diodes • timer doing 1000 ticks per second • power source: 6 AA batteries Lego Mindstorms EV3 Motors • electric motors (2 large and 1 medium-sized), built-in gear • synchronization, built-in rotation sensor (accuracy +- 1 deg) • typical use: • set power (0-100), direction (fwd, rev), set on/off, or • turn the shaft by a given angle at a given power. Lego Mindstorms EV3 Sensors • touch sensor - analogue, pressed/not pressed Lego Mindstorms EV3 Sensors • touch sensor - analogue, pressed/not pressed • colour sensor - digital, 3 modes: colour recognition, measuring intensity of ambient/reflected light Lego Mindstorms EV3 Sensors • touch sensor - analogue, pressed/not pressed • colour sensor - digital, 3 modes: colour recognition, measuring intensity of ambient/reflected light • infrared sensor - digital, 2 modes: • proximity mode: measures distance to objects (0 – 70 cm), accuracy depends on size, shape and composition of objects • beacon mode: measures distance and angle to IR beacon (up to 200 cm) • IR beacon - acts as a beacon or an RC device, requires 2 AAA batteries Digital sensors sample rate 1 kHz. Lego Mindstorms EV3 Sensors • touch sensor - analogue, pressed/not pressed • colour sensor - digital, 3 modes: colour recognition, measuring intensity of ambient/reflected light • infrared sensor - digital, 2 modes: • proximity mode: measures distance to objects (0 – 70 cm), accuracy depends on size, shape and composition of objects • beacon mode: measures distance and angle to IR beacon (up to 200 cm) • IR beacon - acts as a beacon or an RC device, requires 2 AAA batteries Digital sensors sample rate 1 kHz. Additional sensors (not bundled): • gyro sensor (or use gyro-capable smartphone...) • ultrasound sensor Lego Mindstorms EV3 Programming Languages and Environments Visual: • bundled visual language (EV3-G, based on LabView’s G) “Code-based”: • leJOS EV3 • a Java Virtual Machine for EV3 brick • comes with a well-documented API • plug-ins for Eclipse • EV3 version: 0.9 beta, recommended Lego Mindstorms EV3 Programming Languages and Environments Visual: • bundled visual language (EV3-G, based on LabView’s G) “Code-based”: • leJOS EV3 • a Java Virtual Machine for EV3 brick • comes with a well-documented API • plug-ins for Eclipse • EV3 version: 0.9 beta, recommended • C-like alternatives: • NXC (Not eXactly C): originally for NXT, IDE for Win (BricxCC), development stopped in 2013, EV3 support experimental • RobotC: proprietary (1-year license starts at $49), IDE for Win. Lego Mindstorms EV3 Programming Languages and Environments II ev3dev • http://www.ev3dev.org/ • customized Debian (8.0) Linux Distribution • allows access to EV3’s native devices via standard file access • provides rich a set of libraries and language bindings allowing their use in many standard languages: C++, Lua, Python, C... • distro comes with several of these languages (Python, Lua), others can be installed (if ARM9 port exists) • still in development, may require substantial tweaking Lego Mindstorms EV3 Project: Organization • work in teams of two • each team chooses a leader • work :) • submit a project report (up to 5 pages) and program source • presentation of results Submission deadlines: TBA Lego Mindstorms EV3 Project: Requirements • the robot performs a non-trivial, meaningful and a well-defined task. • the robot uses at least 2 motors and 2 sensors • the implementation uses concurrency in a meaningful way (at least 2 threads running in parallel) • the resulting system is a hard real-time system (i.e., a successful completion of the defined task depends on a correct timing) • implementation in leJOS is preferred, choice of a different language should be consulted in advance Lego Mindstorms EV3 Project: Evaluation Project report: • up to 5 pages • describes: the task performed, the implementation, deviations from abstract, difficulties encountered during implementation, use of concurrency and timing • specifies the contribution of individual members (does not have to be equal, but team members may “kick out” work-avoiding colleagues) Lego Mindstorms EV3 Project: Evaluation Project report: • up to 5 pages • describes: the task performed, the implementation, deviations from abstract, difficulties encountered during implementation, use of concurrency and timing • specifies the contribution of individual members (does not have to be equal, but team members may “kick out” work-avoiding colleagues) Source code: • preferably non-visual, non-proprietary language • well-documented source code Lego Mindstorms EV3 Project: Evaluation Project report: • up to 5 pages • describes: the task performed, the implementation, deviations from abstract, difficulties encountered during implementation, use of concurrency and timing • specifies the contribution of individual members (does not have to be equal, but team members may “kick out” work-avoiding colleagues) Source code: • preferably non-visual, non-proprietary language • well-documented source code Presentation: • with demo, not necessarily by the team leader, rehearse in advance! Lego Mindstorms EV3 Project: Evaluation II Golden rules: • Purpose of the project is learning, not building the “best” robot or a “safe” robot that works well under every circumstance (be a bit ambitious!). Lego Mindstorms EV3 Project: Evaluation II Golden rules: • Purpose of the project is learning, not building the “best” robot or a “safe” robot that works well under every circumstance (be a bit ambitious!). • Failures are ok, provided that you transform them into a lesson that can be shared with others (but it is nice to have a robot that does at least “something”). Lego Mindstorms EV3 Project: Evaluation II Golden rules: • Purpose of the project is learning, not building the “best” robot or a “safe” robot that works well under every circumstance (be a bit ambitious!). • Failures are ok, provided that you transform them into a lesson that can be shared with others (but it is nice to have a robot that does at least “something”). • Show us that you learned something new and that you are ready to discuss your project, and your project will pass. Lego Mindstorms EV3 Project: Evaluation II Golden rules: • Purpose of the project is learning, not building the “best” robot or a “safe” robot that works well under every circumstance (be a bit ambitious!). • Failures are ok, provided that you transform them into a lesson that can be shared with others (but it is nice to have a robot that does at least “something”). • Show us that you learned something new and that you are ready to discuss your project, and your project will pass. • If the project passes, the final grade is not further influenced by it. Lego Mindstorms EV3 Project: Topic • it is a part of the project to choose an interesting yet doable goal • search the internet for inspiration (e.g., YouTube: Lego Mindstorms) • all-time classics: finding, picking up and transporting an object; following a black line; navigation through a maze; Segway; 2-leg (or 4-leg) walker... • new ideas are appreciated! Lego Mindstorms EV3 Demo Lego Mindstorms EV3 Quick Start Guide • unbox :), put unboxed parts into some nicer box • download and install Lego Mindstorms app, leJOS, or ev3dev • play around for a while, test the sensors etc. • read manuals and tutorials on the web (including the official ones) • build a simple robot and try to run a simple program • discuss the project, write an abstract Lego Mindstorms EV3