comparison: sanguino/cores/arduino/wiring_analog.c
sanguino/cores/arduino/wiring_analog.c
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| 1 /* | |
| 2 wiring_analog.c - analog input and output | |
| 3 Part of Arduino - http://www.arduino.cc/ | |
| 4 | |
| 5 Copyright (c) 2005-2006 David A. Mellis | |
| 6 | |
| 7 This library is free software; you can redistribute it and/or | |
| 8 modify it under the terms of the GNU Lesser General Public | |
| 9 License as published by the Free Software Foundation; either | |
| 10 version 2.1 of the License, or (at your option) any later version. | |
| 11 | |
| 12 This library is distributed in the hope that it will be useful, | |
| 13 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 Lesser General Public License for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU Lesser General | |
| 18 Public License along with this library; if not, write to the | |
| 19 Free Software Foundation, Inc., 59 Temple Place, Suite 330, | |
| 20 Boston, MA 02111-1307 USA | |
| 21 | |
| 22 Modified 28 September 2010 by Mark Sproul | |
| 23 | |
| 24 $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $ | |
| 25 */ | |
| 26 | |
| 27 #include "wiring_private.h" | |
| 28 #include "pins_arduino.h" | |
| 29 | |
| 30 uint8_t analog_reference = DEFAULT; | |
| 31 | |
| 32 void analogReference(uint8_t mode) | |
| 33 { | |
| 34 // can't actually set the register here because the default setting | |
| 35 // will connect AVCC and the AREF pin, which would cause a short if | |
| 36 // there's something connected to AREF. | |
| 37 analog_reference = mode; | |
| 38 } | |
| 39 | |
| 40 int analogRead(uint8_t pin) | |
| 41 { | |
| 42 uint8_t low, high; | |
| 43 | |
| 44 #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) | |
| 45 if (pin >= 54) pin -= 54; // allow for channel or pin numbers | |
| 46 #elif defined(__AVR_ATmega32U4__) | |
| 47 if (pin >= 18) pin -= 18; // allow for channel or pin numbers | |
| 48 #elif defined(__AVR_ATmega1284__) || defined(__AVR_ATmega644p__) | |
| 49 if (pin >= 24) pin -= 24; // allow for channel or pin numbers | |
| 50 #else | |
| 51 if (pin >= 14) pin -= 14; // allow for channel or pin numbers | |
| 52 #endif | |
| 53 | |
| 54 #if defined(__AVR_ATmega32U4__) | |
| 55 pin = analogPinToChannel(pin); | |
| 56 ADCSRB = (ADCSRB & ~(1 << MUX5)) | (((pin >> 3) & 0x01) << MUX5); | |
| 57 #elif defined(ADCSRB) && defined(MUX5) | |
| 58 // the MUX5 bit of ADCSRB selects whether we're reading from channels | |
| 59 // 0 to 7 (MUX5 low) or 8 to 15 (MUX5 high). | |
| 60 ADCSRB = (ADCSRB & ~(1 << MUX5)) | (((pin >> 3) & 0x01) << MUX5); | |
| 61 #endif | |
| 62 | |
| 63 // set the analog reference (high two bits of ADMUX) and select the | |
| 64 // channel (low 4 bits). this also sets ADLAR (left-adjust result) | |
| 65 // to 0 (the default). | |
| 66 #if defined(ADMUX) | |
| 67 ADMUX = (analog_reference << 6) | (pin & 0x07); | |
| 68 #endif | |
| 69 | |
| 70 // without a delay, we seem to read from the wrong channel | |
| 71 //delay(1); | |
| 72 | |
| 73 #if defined(ADCSRA) && defined(ADCL) | |
| 74 // start the conversion | |
| 75 sbi(ADCSRA, ADSC); | |
| 76 | |
| 77 // ADSC is cleared when the conversion finishes | |
| 78 while (bit_is_set(ADCSRA, ADSC)); | |
| 79 | |
| 80 // we have to read ADCL first; doing so locks both ADCL | |
| 81 // and ADCH until ADCH is read. reading ADCL second would | |
| 82 // cause the results of each conversion to be discarded, | |
| 83 // as ADCL and ADCH would be locked when it completed. | |
| 84 low = ADCL; | |
| 85 high = ADCH; | |
| 86 #else | |
| 87 // we dont have an ADC, return 0 | |
| 88 low = 0; | |
| 89 high = 0; | |
| 90 #endif | |
| 91 | |
| 92 // combine the two bytes | |
| 93 return (high << 8) | low; | |
| 94 } | |
| 95 | |
| 96 // Right now, PWM output only works on the pins with | |
| 97 // hardware support. These are defined in the appropriate | |
| 98 // pins_*.c file. For the rest of the pins, we default | |
| 99 // to digital output. | |
| 100 void analogWrite(uint8_t pin, int val) | |
| 101 { | |
| 102 // We need to make sure the PWM output is enabled for those pins | |
| 103 // that support it, as we turn it off when digitally reading or | |
| 104 // writing with them. Also, make sure the pin is in output mode | |
| 105 // for consistenty with Wiring, which doesn't require a pinMode | |
| 106 // call for the analog output pins. | |
| 107 pinMode(pin, OUTPUT); | |
| 108 if (val == 0) | |
| 109 { | |
| 110 digitalWrite(pin, LOW); | |
| 111 } | |
| 112 else if (val == 255) | |
| 113 { | |
| 114 digitalWrite(pin, HIGH); | |
| 115 } | |
| 116 else | |
| 117 { | |
| 118 switch(digitalPinToTimer(pin)) | |
| 119 { | |
| 120 // XXX fix needed for atmega8 | |
| 121 #if defined(TCCR0) && defined(COM00) && !defined(__AVR_ATmega8__) | |
| 122 case TIMER0A: | |
| 123 // connect pwm to pin on timer 0 | |
| 124 sbi(TCCR0, COM00); | |
| 125 OCR0 = val; // set pwm duty | |
| 126 break; | |
| 127 #endif | |
| 128 | |
| 129 #if defined(TCCR0A) && defined(COM0A1) | |
| 130 case TIMER0A: | |
| 131 // connect pwm to pin on timer 0, channel A | |
| 132 sbi(TCCR0A, COM0A1); | |
| 133 OCR0A = val; // set pwm duty | |
| 134 break; | |
| 135 #endif | |
| 136 | |
| 137 #if defined(TCCR0A) && defined(COM0B1) | |
| 138 case TIMER0B: | |
| 139 // connect pwm to pin on timer 0, channel B | |
| 140 sbi(TCCR0A, COM0B1); | |
| 141 OCR0B = val; // set pwm duty | |
| 142 break; | |
| 143 #endif | |
| 144 | |
| 145 #if defined(TCCR1A) && defined(COM1A1) | |
| 146 case TIMER1A: | |
| 147 // connect pwm to pin on timer 1, channel A | |
| 148 sbi(TCCR1A, COM1A1); | |
| 149 OCR1A = val; // set pwm duty | |
| 150 break; | |
| 151 #endif | |
| 152 | |
| 153 #if defined(TCCR1A) && defined(COM1B1) | |
| 154 case TIMER1B: | |
| 155 // connect pwm to pin on timer 1, channel B | |
| 156 sbi(TCCR1A, COM1B1); | |
| 157 OCR1B = val; // set pwm duty | |
| 158 break; | |
| 159 #endif | |
| 160 | |
| 161 #if defined(TCCR2) && defined(COM21) | |
| 162 case TIMER2: | |
| 163 // connect pwm to pin on timer 2 | |
| 164 sbi(TCCR2, COM21); | |
| 165 OCR2 = val; // set pwm duty | |
| 166 break; | |
| 167 #endif | |
| 168 | |
| 169 #if defined(TCCR2A) && defined(COM2A1) | |
| 170 case TIMER2A: | |
| 171 // connect pwm to pin on timer 2, channel A | |
| 172 sbi(TCCR2A, COM2A1); | |
| 173 OCR2A = val; // set pwm duty | |
| 174 break; | |
| 175 #endif | |
| 176 | |
| 177 #if defined(TCCR2A) && defined(COM2B1) | |
| 178 case TIMER2B: | |
| 179 // connect pwm to pin on timer 2, channel B | |
| 180 sbi(TCCR2A, COM2B1); | |
| 181 OCR2B = val; // set pwm duty | |
| 182 break; | |
| 183 #endif | |
| 184 | |
| 185 #if defined(TCCR3A) && defined(COM3A1) | |
| 186 case TIMER3A: | |
| 187 // connect pwm to pin on timer 3, channel A | |
| 188 sbi(TCCR3A, COM3A1); | |
| 189 OCR3A = val; // set pwm duty | |
| 190 break; | |
| 191 #endif | |
| 192 | |
| 193 #if defined(TCCR3A) && defined(COM3B1) | |
| 194 case TIMER3B: | |
| 195 // connect pwm to pin on timer 3, channel B | |
| 196 sbi(TCCR3A, COM3B1); | |
| 197 OCR3B = val; // set pwm duty | |
| 198 break; | |
| 199 #endif | |
| 200 | |
| 201 #if defined(TCCR3A) && defined(COM3C1) | |
| 202 case TIMER3C: | |
| 203 // connect pwm to pin on timer 3, channel C | |
| 204 sbi(TCCR3A, COM3C1); | |
| 205 OCR3C = val; // set pwm duty | |
| 206 break; | |
| 207 #endif | |
| 208 | |
| 209 #if defined(TCCR4A) | |
| 210 case TIMER4A: | |
| 211 //connect pwm to pin on timer 4, channel A | |
| 212 sbi(TCCR4A, COM4A1); | |
| 213 #if defined(COM4A0) // only used on 32U4 | |
| 214 cbi(TCCR4A, COM4A0); | |
| 215 #endif | |
| 216 OCR4A = val; // set pwm duty | |
| 217 break; | |
| 218 #endif | |
| 219 | |
| 220 #if defined(TCCR4A) && defined(COM4B1) | |
| 221 case TIMER4B: | |
| 222 // connect pwm to pin on timer 4, channel B | |
| 223 sbi(TCCR4A, COM4B1); | |
| 224 OCR4B = val; // set pwm duty | |
| 225 break; | |
| 226 #endif | |
| 227 | |
| 228 #if defined(TCCR4A) && defined(COM4C1) | |
| 229 case TIMER4C: | |
| 230 // connect pwm to pin on timer 4, channel C | |
| 231 sbi(TCCR4A, COM4C1); | |
| 232 OCR4C = val; // set pwm duty | |
| 233 break; | |
| 234 #endif | |
| 235 | |
| 236 #if defined(TCCR4C) && defined(COM4D1) | |
| 237 case TIMER4D: | |
| 238 // connect pwm to pin on timer 4, channel D | |
| 239 sbi(TCCR4C, COM4D1); | |
| 240 #if defined(COM4D0) // only used on 32U4 | |
| 241 cbi(TCCR4C, COM4D0); | |
| 242 #endif | |
| 243 OCR4D = val; // set pwm duty | |
| 244 break; | |
| 245 #endif | |
| 246 | |
| 247 | |
| 248 #if defined(TCCR5A) && defined(COM5A1) | |
| 249 case TIMER5A: | |
| 250 // connect pwm to pin on timer 5, channel A | |
| 251 sbi(TCCR5A, COM5A1); | |
| 252 OCR5A = val; // set pwm duty | |
| 253 break; | |
| 254 #endif | |
| 255 | |
| 256 #if defined(TCCR5A) && defined(COM5B1) | |
| 257 case TIMER5B: | |
| 258 // connect pwm to pin on timer 5, channel B | |
| 259 sbi(TCCR5A, COM5B1); | |
| 260 OCR5B = val; // set pwm duty | |
| 261 break; | |
| 262 #endif | |
| 263 | |
| 264 #if defined(TCCR5A) && defined(COM5C1) | |
| 265 case TIMER5C: | |
| 266 // connect pwm to pin on timer 5, channel C | |
| 267 sbi(TCCR5A, COM5C1); | |
| 268 OCR5C = val; // set pwm duty | |
| 269 break; | |
| 270 #endif | |
| 271 | |
| 272 case NOT_ON_TIMER: | |
| 273 default: | |
| 274 if (val < 128) { | |
| 275 digitalWrite(pin, LOW); | |
| 276 } else { | |
| 277 digitalWrite(pin, HIGH); | |
| 278 } | |
| 279 } | |
| 280 } | |
| 281 } | |
| 282 |
