Microcontrollers and Interfacing

Transcription

1 Microcontrollers and Interfacing Week 11 input/output device summary project suggestions College of Information Science and Engineering Ritsumeikan University 1

2 2 this week various input/output devices sensors displays mechanical actuators communication project suggestions input elements output elements computing elements complete projects

3 3 devices: discrete sensors for use with breadboard: temperature photocell (visible light) photodiode (infra-red light) momentary push switch (e.g., use many to make musical keyboard) potentiometer (rotary position with 300 range) electrostatic field rotary encoder 360 range (continuous rotation) 2-bit Gray code output ( quadrature ) outputs D0 D1

4 4 shield: game controller joystick + four momentary switches analogue joystick on A0, A1 buttons on D3, D4, D5, D6 not quite stackable wires to connect headers to discrete devices jumpers to connect headers to breadboard could be used above a stackable shield to make wireless controller...

5 shield: wi-fi stackable shield; use with: game controller LCD display etc. pairs with other XBee devices similar to Bluetooth but over real Wi-Fi long range 100 m indoors same interface as Serial device print(), write(), read(), etc. data exchanged with paired devices 5

6 6 shields: device backplanes Grove series of devices shield for Arduino (and many others) single connector type (4-pin header) many signals routed to connectors analogue inputs digital input/output (in pairs) I 2 C bus many compatible devices libraries for ease of use

7 devices: sensors angle (potentiometer) rotary encoder 3-axis gyroscope (I2 C) 3-axis accelerometer (I2 C) 7

8 devices: sensors touch button sound light temperature distance 8

9 9 devices: actuators relay (single-pole single-throw) servo motor

10 devices: displays simple LED buzzer 2-line LCD dot-matrix display 4-digit LED display 10

11 shields: displays colour LCD touch screen resolution access via library draw lines, rectangles, text read pressure input & position 11

12 12 shields: displays LoLshield (Lots of LEDs) 14 9 array of LEDs uses 12 digital pins (D2 to D13) each LED individually addressable Charlieplexing connects many LEDs to a few pins (see Wikipedia entry for details) library hides complexity of addressing LedSign::Set(), LedSign::Clear(), etc. double-buffering for smooth scrolling

13 13 improving on the serial monitor Serial monitor has no raw keypress input (line-oriented only) nothing send to Arduino until send is pressed has no cursor control (other than newline ) cannot display in colour solve all these problems using a terminal emulator send keystrokes immediately cursor control (VT100 emulation) for interactive/status displays in a terminal: screen ttyname baudrate e.g: screen /dev/cu.usbmodem built into Linux, MacOS; download for Windows (or use PuTTY) terminate by typing Control-A Control-\

14 14 complete project suggestions 1: easy 4-digit clock using I 2 C display far too easy! wireless chat (using wi-fi communication) use two Arduinos connect a real terminal emulator to the USB serial exchange characters from one side to the other via wi-fi also too easy! electrostatic field strength meter: explore the invisible electrial environment 8-bit R-2R ladder DAC, made from discrete resistors add an ouput buffer to make it really useful

15 15 complete project suggestions 1: easy N-bit binary number b 0 b 1 b N-2 b N-1 2R 2R 2R 2R R R R V OUT 2R 5V op-amp buffer transistor buffer GND V IN + - V OUT V IN V OUT

16 16 complete project suggestions 2: easy 4-digit clock using shift register(s) and four seven-segment displays one shift register with multiplexing of displays, or four shift registers connected in series flashing hour/minute separator (of course) set time from serial monitor to move this to medium category: add an alarm, and push buttons to set time/alarm monophonic musical instrument using switches or voltage input calculate the frequencies needed and use tone() to play them push button switches to make one octave of piano keyboard, or electrostatic field strength controling pitch (a Theramin ) to move this to the difficult category: make a sequencer add a button to start/stop recording, and a button to start/stop playback

17 17 complete project suggestions 3: medium sun (or light) tracker using multiple photocells and analogue inputs add a servo motor to physically indicate the position colour meter using red, green, blue LEDs and a photocell/photodiode turn on one LED at a time, measure reflected light intensity projects using external DAC via SPI and DDS (google it) or a wave table : function generator: sine, triangle or square waves of any desired frequency chord generator (mix three frequencies to make major/minor chords) polyphonic musical instrument (similar to monophonic one in easy category)

18 18 complete project suggestions 4: medium 2-axis level indicator horizontal: tells you when a surface is flat, or vertical: for taking pictures (an artificial horizon ) key matrix scanner to implement lots of switches (e.g., 32) using few digital signals add sotware de-bounce to promote this to difficult category wired or wireless game controller for pong (or some other game) one Arduino runs the controller another Arduino runs the game (e.g., the LoLshield example pong game) connect using serial: wi-fi (easy) or two wires (slightly harder)

19 19 complete project suggestions 5: difficult audio processor (reverb, phaser, short delay, etc., via external ADC and DAC) limited by memory size (requirements = audio quality effect length) infra-red communication with DIY serial protocol implement your own serial communication (and make, e.g., a text chat) IR LED transmitter, IR detector receiver explicit frame encoding/decoding: start bit, data bits, parity, stop bit(s), etc. morse code encoder: type a message into the serial monitor... audible version played on speaker, visible version shown on bar graph(s) scroll the bar graph(s) for longer messages modular wireless LoLShield display cell for creating large displays control and coordinate as many as you like from a central location

20 complete project suggestions 6: difficult telemetry: environmental monitor (e.g., temperature) use Processing to display a 7-day graphical chart on a computer audio alarm message or ring tone 8-bit 8kHz audio, 512kHz PWM, bypassing the Arduino library direct hardware programming, via memory-mapped registers particle-based fluid simulator (accelerometer + LoLshield tank ) fluid obeys gravity when tank is tilted seven-band stereo audio spectrum analyser input from headphone connection MSGEQ7 seven-band filter/adc IC display: bar graphs, LoL Shield, LCD, etc. 20

21 21 complete project suggestions 7: flexible invent your own project! use any input/output devices to gather/display information perform any function in between

22 22 your project highly recommended: install the Arduino IDE on your own computer choose a project you feel confident you can finish one of the suggested projects possibly modified: different input, output, etc. a project of your own invention work in your teams of two or three people make a rough design of your project before you begin collaborate on all parts, or delegate responsibilies request any hardware that you need (by or in person) as soon as you know you will need it! we only have a few of some things, but it is easy to buy more

23 23 your project search google (or similar) for information explanations about how a device works Arduino libraries to download and install ask the instructor about anything you are having difficulty with time is short, and help is always available do not become blocked because you cannot understand something use to ask for help or advice: piumarta@cs.ritsumei.ac.jp borrow your Arduino hardware kit and work on your project outside of class you are supposed to spend several hours per class on homework! use class time for asking questions and getting help with problems

24 24 your project if you finish quickly, extend your project but always be sure it is easy to revert to the last working version agenda: weeks 12, 13 and 14 project work week 15 project presentations you must present your project to pass this class presentations should last between five and ten minutes each member of the team must say at least a few words about the project be prepared to explain the design, the hardware, and the software practice (at least once) to make sure your presentation is within the time limits

25 25 next week this week there is real homework: discuss within your team which project you will attempt develop some ideas about what you hardware you will need tell me before next week if you need any hardware that is not already in your kit additional reference material for completing your project be prepared to explain your project idea at the start of class next week next week: brief explanation from each team about which project they have chosen try to explain in less than one minute questions and comments will be welcome from everyone project work, week 1

26 26 exercises Lots of LEDs: LoL Shield

27 27 LoL Shield API #include "Charliplexing.h" Init(uint8_t mode = 0) initializes the library. The mode argument can be used to enable support for double-buffering (DOUBLE_BUFFER) and/or greyscale (GRAYSCALE). SetBrightness(uint8_t brightness) sets the overall brightness of the screen, between 0 and 127. Set(uint8_t x, uint8_t y, uint8_t c = 1) turns on the LED at coordinates (x, y). To turn it on full brightness, the value 7 should be passed as the third argument c. Clear(uint8_t c = 0) sets the brightness of all the LEDs to c. (The default value 0 turns them all off.) Flip(bool blocking = false) swaps the front and back buffers, if double-buffering is enabled. Horizontal(uint8_t y, uint8_t c = 0) fills an entire row with the specified value (0 for off, 7 for full on). Vertical(uint8_t x, uint8_t c = 0) fills an entire column with the specified value (0 for off, 7 for full on).