CHAPTER 16 RESOURCES 409 Add a file called keywords.txt to your library directory and list the class and functions in it. After each one, add a single tab (not spaces) and specify whether it is a class (KEYWORD1) or method (KEYWORD2). In our case, we have just one class and one public method, so the end result looks like this: TouchScreen KEYWORD1 read KEYWORD2 If our class happened to have more methods in, it they would also be labeled with KEYWORD2. The IDE will then highlight anything labeled KEYWORD1 in orange and anything labeled KEYWORD2 in brown. Restart your IDE, open the example ReadTouchscreen pr ogram again, and you should see that the syntax highlighting is now correct. The complete TouchScreen library is available for download from GitHub, so if you want to see the end result and how it all fits together you can grab it from github.com/practicalarduino/TouchScreen. Platform-Specific Variations Most of the time you can write a library that will run perfectly well on just about any Arduino, from a Mini to a Mega, with no changes required. Sometimes, though, there are differences between the various Arduino models that can cause problems, and the TouchScreen library we used in this example is one of them. The code as described here will work perfectly well on almost all Arduino models, but will break on a Mega because it has a different system for numbering its analog and digital pins. On most Arduino models analog pins 0 through 5 can also be referenced as digital pins 14 through 19, and we do that in the library by simply adding 14 to the analog pin number to derive the digital pin number. But the Mega has far more I/O pins, so rather than starting the analog pins at number 14, it starts them at number 54. The re sult is that the code we’ve created here will appear to compile cleanly on a Mega, but will totally fail to work because it will be referencing the wrong pins. Luckily, this problem is made very easy to solve because we used a #define to specify the value for DIGITAL_OFFSET, and we can use special values set in the build environment to make decisions about how the library should be compiled and then build it differently in different circumstances. Doing an explicit check for the ATMega1280 CPU used in the Arduino Mega, we can change the original single #define entry so that it instead defines one value for the Mega and a different value for anything else. #if defined(__AVR_ATmega1280__) #define DIGITAL_OFFSET 54 #else #define DIGITAL_OFFSET 14 #endif The library will then work interchangeably on no rmal Arduino models and also on the Mega. Summary The Arduino is an incredibly useful platform, capable of controlling both practical projects and fun gadgets. It also has a very strong and enthusiastic community of developers and gadgeteers, and we hope you will enjoy becoming part of that community. 411 Index Symbols and Numerics #define, 251, 342 1.5V batteries, 10 1/4W resistors, 14 1K resistor, 86−87, 90, 246 1N4004 diodes, 24 22uF electrolytic capacitor, 276 3D cube program, 129 433MHz receiver module, 243 433MHz receiver modules, 240 47uF electrolytic capacitor, 321−322 4-bit mode, 169 4K7 EOL resistors, 86 4K7 pull-up resistor, 86−87 4K7 pull-up resistors, 90 6-pin mini-DIN panel sockets, 67−69 6-pin mini-DIN sockets, 66 6V battery, 10 74HC4094, 169 78xx series regulators, 383 −384 9V batteries, 10 A accu_trip() function, 356 ADC, 194−197 division factor, 196 prescaler bits, 196 ADC clock rate, 196 ADR79/01, 296 Aiko application framework, 45−46 alarm sensor shield, 87−92 alarm systems. See security systems alligator clip, 194 Allophone Speech Processor, 139 allophone-based speech synthesis, 142 allophones, 142, 157, 160 Allophones, 154 allowedTags array, 290 ambient atmospheric pressure, 209 amperes (A), 2 amplifier for speech synthesizer, 149−151 analog circuits, 392 analog voltage converting to digital value, 194−197 analogRead() function, 99, 229 analog-to-digital converters (ADCs), 186 analyse_cmd(), 110 analyse_cmd() function, 113 appliance remote control instructions assemble reed relay shield, 21−25 connect reed relay shield to remote control, 25 create reed relay control program, 27−28, 30−32 test and investigate appliance remote, 19−21 parts required, 17−18 schematic, 18 test reed relay shield, 32−33 variations automatic trigger, 34 socket connections, 35 412 wireless link, 34 appliance remote control, 17, 35 ApplianceRemoteControl, 27−28, 30 ApplianceRemoteControlCompact, 27, 30−32 Arduino connecting keyboard to, 63, 80 connecting mouse to, 63, 76 −78 mounting, 137 Arduino community sharing work with, 1 Arduino Duemilanove. See Duemilanove pin-change interrupts for, 345 Arduino library writing, 401, 404−406, 408 develop functionality, 402 −403 encapsulation of, 403−405 example sketch, 407−408 library class file, 405−407 library header file, 403−405 platform-specific variations, 409 supporting files, 408−409 Arduino Mega, 175, 184, 189 pin-change interrupts for, 346 Arduino Pro Mini, 189 Arduinoscope, 204−205 arrays multidimensional, 253 ASCIINUMBASE, 251 AT keyboard, 63−64 ATDPN (ATtentionCOL Describe Protocol by Number) command, 353 ATMega chip, 13 ATMega chips, 139 ATMega CPU, 166−167, 190 ATMega1280 CPU, 296 attachInterrupt() function, 179 B back-EMF, 24 BAP tags, 270 barcode reader, 79 batteries, 10 battery-assisted passive (BAP) tags, 270 bidirectional interfaces, 168 bipolar transistors, 15 bipolar transitors, 391−392 bit banging, 116, 296 blinkLed() function, 47 Buffer Half Full signal, 161 button de-bouncing, 180 buttonState variable, 342 C C++ methods, 406 C++ objects, 403 camera shutter release camera modification for, 43 infrared remote control, 42, 43 remote release connector, 40 −42 Canon cameras, 41−42 capacitance (C), 11-13 capacitors, 11−13, 15 carAlarmScreen option, 340, 381 Cat5 network cabling, 8 cathod-ray oscilloscopes (CRO), 186 cbi() function, 199 charlieplexing, 387 −388 check_mil_code() function, 359 −360 checkSensor() function, 96−97 checksum calculation function, 259 chording keyboard, 61 clamping, 55 CLOCK pin connection, 74, 76 config parameters, 363 config_menu() function, 363 constrain() function, 137, 229 contrast adjustment trimpot, 169 Controller-Area Network (CAN), 302 CPU RAM allocation, 365 Creative Commons licenses, 1 current, 2, 388 current limiting, 7−8 current-limiting resistors, 245 custom input devices, 51 413 D DATA pin connection, 74, 76 DB9 socket, 333−334 DB9 to OBD-II cable, 313 DC plugpacks, 11 DEBUG option, 339 decoupling capacitor, 244 defines, 251−252 delay loops, 45 delay() function, 45 delayMs() function, 57 detachInterrupt(), 181 diagnostic trouble codes (DTCs), 357 −361 digital input/output expansion, 393−396 digitalWrite(), 331 diodes, 8−9, 15 reverse biased, 24 display() function, 353, 356−357 displayAlarmScreen() function, 381 DIY shields, 72, 73 double end-of-line resistors, 86 draw(), 129 dropout voltage, 384 DS18B20 temperature sensors, 103, 107, 108, 118 Duemilanove, 189 E ECU polling, 340 ECUs (electronic control units), 352 EEPROM (Electrically Erasable Programmable Read-Only Memory), 324 eeprom_read_word() function, 363 eeprom_write_block() function, 363 efficiency of voltage regulators, 384 electro-mechanical relays operation of, 24 electronic circuits debugging, 185 electronics basics, 1−13 capacitance and capacitors, 11−13 choosing wire, 8 current limiting, 7−8 current, voltage, and power, 2 diodes, 8−9 ESD precautions, 13 mains voltages, 2−3 Ohm's law, 7−8 power supplies, 9−11 resistance, 6−8 resistors, 6−7 schematics, 3−5 electrostatic discharge (ESD), 13 elm_compact_response() function, 351, 354 elm_read() function, 351 ELM327 initializing serial connection to, 352 reading from, 351−352 ELM327 adapter, 321 ELM327 chip, 302−303, 308−311 ELM327 OBD-II adapter, 333 ENABLE_GPS option, 339 ENABLE_VDIP option, 339 encapsulation, 404 endKeyStroke() function, 58 end-of-line (EOL) resistors, 84−85, 92, 94−95 engine-management system, 295−296 EOBD (European OBD) standard, 296 erproxy, 265 Ethernet adapters, 103 Ethernet shields, 184, 265 etherShield library, 103, 108 external devices, 388 F farads (F), 11 field effect transistors (FETs), 392 flash memory chips, 324 Flash movies, 233 floating-point (decimal) numbers, 178 414 floatToString() helper function, 342 flow gauges, 163, See also water flow gauge four-channel alarm sensor shield, 87−88, 90−92 FTDI chip, 310 G get_pid() function, 353−356 getPid() function, 348 GGA sentence format, 318−319 global variables, 177 Google Earth, 295, 380 GPS module, 314, 316−319, 337 GPS serial connection, 323 GPS.pde, 370 gpsdump() function, 370 H Hall-effect devices, 174 Hall-effect flow sensor, 166, 173, 178 Hall-effect sensors, 163,178 hardware interrupts, 175−176, 347 HD44780 displays, 169 HD44780 interface, 168 HD44780 LCD module, 329−330 HD44780-compatible displays, 168 HD44780-compatible interfaces, 328 heap pointer, 365 heck_supported_pids() function, 347 hex values, 305 high-frequency (HF) RFID tags, 270 home security system, 99 hooked wire, 8 Host.pde, 372−375 Human Interface Device (HID), 59 I I2C, 324 ickel-cadmium ( NiCd) cells, 10 ID-12 reader module, 287 ID-12 RFID reader modules, 282 −284 IFF systems, 270 image processing Linux, 48 Macintosh, 49 Windows, 48 image tags, 234 impplantable RFID tags, 271 include guard, 403 indicator LEDs, 280−282 Init_RF_Interpreters function, 259−260 initGps() function, 370 initialize() method, 76 initVdip() function, 374 Input Capture Pin (ICP), 253 input conditioning, 396−399 isolated, 398 nonisolated, 396−397 input voltage prescaler, 205−206 input voltages, 396 input/output (I/O) expansion digital, 393−396 interrupt flags, 177 Interrupt Service Routine (ISR), 175, 177, 260−261 interrupts disabling, 181 IR (internal resistance) loss, 8 ISO 14230 KWP2000, 302 isolation, 388 ISR (interrupt service routine), 331 K keyboard software, 73−76 keyboard.read() method, 75 L lastLogWrite variable, 350 LCD module, 168−171 for vehicle telemetry platform, 328 −331 415 mounting, 171−172 LCD pin assignments, 340 LCD.pde, 366−367, 369− 370 lcd_commandWrite() function, 369 lcd_commandWriteSet() function, 368 lcd_gotoXY() function, 367 lcd_init() function, 368 lcd_tickleEnable() function, 368 LEDs, 14 about, 384−385 charlieplexing, 387−388 current limiting resistors with, 245 driving, 384−385, 387−388 indicator, 280−282 multiplexing, 385−387 status, 90−92 library class file, 405−407 library header file, 403−405 light-dependent resistors (LDRs), 49 linear regulator circuits, 384 line-level output cable, 148−149 line-level signals, 147 Linux image processing, 48 LiquidCrystal library, 178, 328, 366 lithium polymer (LiPo) batteries, 11 LM2940CT-5 linear voltage regulator, 320 LM386-based audio amplifier, 150 LM7805 voltage regulator, 320−321 load dump, 320 Locosys LS20031 module, 314 −318 logActive flag, 340, 348, 372 logging control button, 331 −332 logic analyzers about, 186 cost of, 187 logPid byte array, 344 loop() function, 46 low dropout (LDO) regulators, 384 low-frequency (LF) RFID tags, 270 low-pass filters, 147 LQFP-48 format, 325 M Macintosh image processing, 49 macros, 252 mains voltages, 2−3 map() function, 136 −137, 230 Mass Air Flow parameter, 355 mass-storage devices connecting, 324−325, 327 mechanical contacts, 391 mechanical switches, 389−393 MEGA option, 339 memory limitations, 364 −365 memory-mapped peripheral registers, 176 memoryTest() function, 366 metal-oxide–semiconductor field-effect transistors (MOSFETS), 392 MicroSD flash memory cards, 324 millis() function, 183, 260 Mini GPS program, 316−317 mode 0x03, 357−361 modeButton() function, 372 modifier keys, 74 motion detectors, 81 passive infrared (PIR), 85 mouse input, 63 mouse software, 76−78 MPGuino, 297 MPX2010DP, 212 multidimensional array, 253 multimeters, 185 multiplexing, 385−387 multistate voltage divider, 99 multithreaded applications global variables within, 177 multiturn variable resistors, 212 N negative feedback, 212 network proxies, 265 nickel-metal hydride (NiMH) cells, 10 NMEA 0183 sentences, 318 −319 416 nonpolarized capacitors, 12 normally closed (N.C.) sensors, 85 normally closed outputs, 81 normally open (N.O.) sensors, 84−85 normally-closed (N.C.) sensors, 85 nuElectronics, 108 NuElectronics Ethernet Shield, 103 O OBD-Codes site, 359 OBD-II, 296 modes and parameters, 304−308 OBD-II adapters, 302 OBD-II cable assembling, 313−314 OBD-II serial connection, 323 OBD-II standard, 301−302 OBD-II to DB9 cables, 313 OBD-II to USB adapters, 314 OBDtoKML directory, 380 obd-to-kml.php, 380 OBDuino , 297 OBDuino Mega sketch, 338, 340−347, 349, 351−352, 354−356, 358−365, 368−369, 373−375, 377− 378, 380 GPS.pde, 370 Host.pde, 372−375 LCD.pde, 366−367, 369−370 OBDuino Mega.pde, 339−342, 344−354, 356−366 PowerFail.pde, 375 using, 376−380 VDIP.pde, 371, 372 OBDUINO.CSV file, 372 OBDuino Mega.pdf, 339 ohms, 6 Ohm's law, 7−8 on-board amplifier for speech synthesizer, 149−151 On-Board Diagnostics version 2 (OBD-II), 296 online thermometer instructions, 103 assemble sensors, 106−108 connect data lines , 105−106 load program, 108−118 mount PCB plugs on shield, 103 parts required, 101 schematic, 102 variations, 119 online thermometer, 101, 119 op-amp circuits negative feedback on, 212 performance characteristics, 213 tuning, 212 open source software, 1 optocouplers, 389, 393 Organic LED (OLED) modules, 328 oscilloscope/log analyzer analog read version, 198−200 digital read version, 200−202 digital read version with optimized communications, 202−203 instructions connection to circuit under test, 197 install software in Arduino, 198−203 oscilloscope/logic analyzer input voltage prescaler, 185, 205−207 instructions, 189 case assembly, 190−192 fit prototyping shield, 193 install Processing, 203−205 make test probes, 194 run visualization program, 203−205 successive approximation ADC, 194−197 parts required, 187 −188 resources, 206 schematic, 189 variations, 205−206 oscilloscopes about, 185−186 cathode-ray, 186 cost of, 187 output circuitry, 388−393 417 P Pachube, 184, 236 Panasonic cameras, 40, 41 panel-mount sockets, 67−69 parallel interfaces, 168 Parameter IDs (PIDs), 304−308 params_load() function, 363 params_save() function, 348, 363 params_t struct, 344 parts, 14−15 passive infrared (PIR) motion detectors, 85, 92−93 placement of, 98 soldering EOL resistors onto, 94 trigger-and-hold function, 96 triggering of, 94 warming up, 98 PCB plugs mounting, on shield, 103, 105 PCB-mount 6-pin mini-DIN so ckets, 66 PCB-mount buttons, 20 PCMSK (pin change mask), 345 phonemes, 142 PhotoLapse, 48 PIDs, 342, 354 Pin Change Interrupt Control Register (PCICR), 346 Pin Change Interrupt number (PCINT), 346 Pin Change Interrupt Register, 346 pin change interrupts, 346 Pin Change Mask (PCMSK), 346 pin-change interrupts, 345− 346 pinMode() function, 200 plugpacks, 11 polarized capacitors, 12 port-level interrupts, 341, 346 power, 2 power dissipation, 384 power failures, 321 power supplies, 9 batteries, 10 USB power, 9 wall warts/plugpacks, 11 power supply bypass, 13 power supply circuit for vehicle telemetry platform, 319 −323 powerFail() function, 375 PowerFail.pde, 375 pressure transducer, 209, 212 above-tank mount, 216 external mount, 219 in-pipe mount, 218 inside-tank mount, 217 installation methods, 216−218 installation options, 215 pin assignments, 223 pin numbers and ports for, 222 print() function, 230, 234 print_webpage() function, 110-111 println() function, 230 processGpsBuffer() function, 347, 370 processHostCommands() function, 372 Processing, 128−131, 187 Processing programming language, 98 processVdipBuffer() function, 371 PROGMEM directive, 234 PROGMEM keyword, 343 prototyping shields DIY, 399−400 PS/2 barcode scanner, 79 PS/2 connections, 65 PS/2 extension cable, 69−72 PS/2 keyboard, 63, 80 instructions, 64 6-pin mini-DIN panel sockets, 66−69 keyboard software, 73−76 PS/2 connections, 65 PS/2 extension cable, 69−72 parts required, 63−64 schematic, 65 variations, 79 PS2Keyboard library, 73−76 PS2Mouse library, 76−78 PString class, 339 PString library, 347 pull-down resistors, 166 pull-up resistors, 166 418 pulseCount variable, 176 pulseOutput function, 31, 32 pulse-width–modulated (PWM) carrier, 144 PWM (pulse-width modulation), 302 Q QuickTime, 49 R radio antenna, 249 radio antennas, 249 RCA connectors, 143 RDM360 reader, 284−285 read() method, 406 README file, 408 rechargeable batteries, 10 reed relay shield assembling, 21−22, 24−25 connecting to remote control, 25 testing, 32−34 reed relays, 21, 389− 390 creating control program, 27 − 28, 30−32 for camera controller, 39 registers setting, 254 relays, 389 about, 390−391 reed, 389−390 report() function, 77 resistance, 6, 8 resistive touch screens workings of, 123−126 resistors, 6−7 light-dependent, 49 resolution, 195 resource consumption, 163 reverse biased diodes, 24 reverse spikes, 24 RF_Interpreter_ WS2355() function, 261 RFID access control system extensible read head, 292 instructions, 274 assemble prototyping shield, 275 assemble RDM630 reader, 284−285 ID-12 reader module, 282−284 indicator LEDs, 280−282 install Arduino, 292 install reader, 291−292 install strike plate, 291 manual release button, 282 power supply, 275−277 relay output, 278 −280 RFID serial connection, 277 −278 variations, 292−294 intelligent desk pad, 294 parts required, 272 −273 resources, 294 schematic, 274 sketch, 285−290 speech synthesizer feedback, 293 RFID access control system, 269, 294 RFID reader modules, 274−275 RFID systems architecture, 269 early, 269 RFID tags, 270−272 RFID technology, 269−270 rocessVdipBuffer() function, 374 RS-232 adapter, 302−303 RTS (ready to send) pin, 349 RXB1 433MHz receiver module, 243, 246−250 S SAE J1850 standard, 302 sbi() function, 199 scancodes, 73−74 schematics defined, 3 reading, 3−5 SDuFAT (SD micro FAT), 324 Sealed lead acid (SLA) batteries, 10 security system sensors . work interchangeably on no rmal Arduino models and also on the Mega. Summary The Arduino is an incredibly useful platform, capable of controlling both practical projects and fun gadgets. It. header file, 403−405 platform-specific variations, 409 supporting files, 408−409 Arduino Mega, 175, 184, 189 pin-change interrupts for, 346 Arduino Pro Mini, 189 Arduinoscope, 204−205 arrays. grab it from github.com/practicalarduino/TouchScreen. Platform-Specific Variations Most of the time you can write a library that will run perfectly well on just about any Arduino, from a Mini