avr/nano/main.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <limits.h>
   4 #include <avr/io.h>
   5 #include <avr/interrupt.h>
   6 #include <avr/sleep.h>
   7 #include <util/delay.h>
   8 #include <util/twi.h>
   9 #include <avr/eeprom.h>
  10 #include <avr/wdt.h>
  11 #include <avr/pgmspace.h>
  12 #include "uart.h"
  13
  14 /*
  15  * I2C Register Map (8 Bit)
  16  * 0x00 Register select
  17  * 0x01 Distance left MSB
  18  * 0x02 Distance left LSB
  19  * 0x03 Distance right MSB
  20  * 0x04 Distance right LSB
  21  * 0x05 Distance forward1 MSB
  22  * 0x06 Distance forward1 LSB
  23  * 0x07 Distance backward MSB
  24  * 0x08 Distance backward LSB
  25  * 0x09 Voltage MSB
  26  * 0x0A Voltage LSB
  27  * 0x0B Distance forward2 MSB
  28  * 0x0C Distance forward2 LSB
  29  * 0x0D Current MSB
  30  * 0x0E Current LSB
  31  *
  32  * 0x15 Distance forward1 MSB (read only)
  33  * 0x16 Distance forward1 LSB (read only)
  34  * 0x17 Distance backward MSB (read only)
  35  * 0x18 Distance backward LSB (read only)
  36  * 0x19 Distance forward2 MSB (read only)
  37  * 0x1A Distance forward2 LSB (read only)
  38  *
  39  * 0xff Bootloader
  40  */
  41
  42
  43 /**
  44  * Nano Pinout
  45  * A0 PC0/ADC0
  46  * A1 PC1/ADC1
  47  * A2 PC2/ADC2
  48  * A3 PC3/ADC3
  49  * A4 PC4/ADC4
  50  * A5 PC5/ADC5
  51  * A6 ADC6
  52  * A7 ADC7
  53  * D0 PD0/RX
  54  * D1 PD1/TX
  55  * D2 PD2/IND0
  56  * D3 PD3/IND1
  57  * D4 PD4/T0
  58  * D5 PD5/T1
  59  * D6 PD6/AIN0
  60  * D7 PD7/AIN1
  61  * D8 PB0/ICP
  62  * D9 PB1/OC1
  63  * D10 PB2/SS
  64  * D11 PB3/MOSI
  65  * D12 PB4/MISO
  66  * D13 PB5/SCK
  67  */
  68
  69
  70 #define TWI_ACK   TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWEN) | (1<<TWIE)
  71 #define TWI_NAK   TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
  72 #define TWI_RESET TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWSTO) | (1<<TWEN) | (1<<TWIE);
  73
  74 static volatile uint8_t ireg=0;
  75 static volatile uint8_t bootloader=0;
  76 static volatile uint16_t dist_left=0;
  77 static volatile uint16_t dist_right=0;
  78 static volatile uint16_t dist_forward1=0;
  79 static volatile uint16_t dist_forward2=0;
  80 static volatile uint16_t dist_backward=0;
  81 static volatile uint8_t start_dist_fwd1=0;
  82 static volatile uint8_t start_dist_fwd2=0;
  83 static volatile uint8_t start_dist_bwd=0;
  84 static volatile uint16_t voltage=0;
  85 static volatile uint16_t current=0;
  86 static volatile uint8_t pind_pre=0;
  87
  88 ISR(TWI_vect)
  89 {
  90         static int16_t tmp16=0;
  91
  92         switch(TW_STATUS)
  93         {
  94                 case TW_SR_SLA_ACK: // start write
  95                         TWI_ACK;
  96                         ireg = 0;
  97                         break;
  98                 case TW_SR_DATA_ACK: // write
  99                         switch(ireg) {
 100                                 case 0x00: // register select
 101                                         ireg = TWDR;
 102
 103                                         if (ireg == 0x05) start_dist_fwd1=1;
 104                                         if (ireg == 0x07) start_dist_bwd=1;
 105                                         if (ireg == 0x0b) start_dist_fwd2=1;
 106
 107                                         ireg--; // because we do ireg++ below
 108                                         TWI_ACK;
 109                                         break;
 110                                 case 0xff: // bootloader
 111                                         bootloader = TWDR;
 112                                 default:
 113                                         TWI_NAK;
 114                         }
 115                         if (ireg < 0xff) ireg++;
 116                         break;
 117                 case TW_ST_SLA_ACK: // start read
 118                 case TW_ST_DATA_ACK: // read
 119                         switch(ireg) {
 120                                 case 0x01: // Distance left MSB
 121                                         tmp16 = dist_left;
 122                                         TWDR = tmp16>>8;
 123                                         TWI_ACK;
 124                                         break;
 125                                 case 0x02: // Distance right LSB
 126                                         TWDR = tmp16;
 127                                         TWI_ACK;
 128                                         break;
 129                                 case 0x03: // Distance right MSB
 130                                         tmp16 = dist_right;
 131                                         TWDR = tmp16>>8;
 132                                         TWI_ACK;
 133                                         break;
 134                                 case 0x04: // Distance right LSB
 135                                         TWDR = tmp16;
 136                                         TWI_ACK;
 137                                         break;
 138                                 case 0x05: // Distance forward1 MSB
 139                                         tmp16 = dist_forward1;
 140                                         TWDR = tmp16>>8;
 141                                         TWI_ACK;
 142                                         break;
 143                                 case 0x06: // Distance forward1 LSB
 144                                         TWDR = tmp16;
 145                                         TWI_ACK;
 146                                         break;
 147                                 case 0x07: // Distance backward MSB
 148                                         tmp16 = dist_backward;
 149                                         TWDR = tmp16>>8;
 150                                         TWI_ACK;
 151                                         break;
 152                                 case 0x08: // Distance backward LSB
 153                                         TWDR = tmp16;
 154                                         TWI_ACK;
 155                                         break;
 156                                 case 0x09: // Voltage MSB
 157                                         tmp16 = voltage;
 158                                         TWDR = tmp16>>8;
 159                                         TWI_ACK;
 160                                         break;
 161                                 case 0x0A: // Voltage LSB
 162                                         TWDR = tmp16;
 163                                         TWI_ACK;
 164                                         break;
 165                                 case 0x0B: // Distance forward2 MSB
 166                                         tmp16 = dist_forward2;
 167                                         TWDR = tmp16>>8;
 168                                         TWI_ACK;
 169                                         break;
 170                                 case 0x0C: // Distance forward2 LSB
 171                                         TWDR = tmp16;
 172                                         TWI_ACK;
 173                                         break;
 174                                 case 0x0D: // Current MSB
 175                                         tmp16 = current;
 176                                         TWDR = tmp16>>8;
 177                                         TWI_ACK;
 178                                         break;
 179                                 case 0x0E: // Current LSB
 180                                         TWDR = tmp16;
 181                                         TWI_ACK;
 182                                         break;
 183                                 case 0x15: // Distance forward1 MSB
 184                                         tmp16 = dist_forward1;
 185                                         TWDR = tmp16>>8;
 186                                         TWI_ACK;
 187                                         break;
 188                                 case 0x16: // Distance forward1 LSB
 189                                         TWDR = tmp16;
 190                                         TWI_ACK;
 191                                         break;
 192                                 case 0x17: // Distance backward MSB
 193                                         tmp16 = dist_backward;
 194                                         TWDR = tmp16>>8;
 195                                         TWI_ACK;
 196                                         break;
 197                                 case 0x18: // Distance backward LSB
 198                                         TWDR = tmp16;
 199                                         TWI_ACK;
 200                                         break;
 201                                 case 0x19: // Distance forward2 MSB
 202                                         tmp16 = dist_forward2;
 203                                         TWDR = tmp16>>8;
 204                                         TWI_ACK;
 205                                         break;
 206                                 case 0x1A: // Distance forward2 LSB
 207                                         TWDR = tmp16;
 208                                         TWI_ACK;
 209                                         break;
 210                                 default:
 211                                         TWDR = 0;
 212                                         TWI_NAK;
 213                         }
 214                         ireg++;
 215                         break;
 216                 case TW_SR_STOP:
 217                         TWI_ACK;
 218                         break;
 219                 case TW_NO_INFO:
 220                         break;
 221                 default:
 222                         TWI_RESET;
 223         }
 224 }
 225
 226
 227 uint16_t ReadChannel(uint8_t mux) {
 228         uint8_t i;
 229         uint16_t result;
 230
 231         ADCSRA = (1<<ADEN) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);    // Frequenzvorteiler
 232         // setzen auf 128 (1) und ADC aktivieren (1)
 233         // 16MHz/128=125kHz
 234
 235         ADMUX = mux;                      // Kanal waehlen
 236         ADMUX |= (1<<REFS0);
 237
 238         /* nach Aktivieren des ADC wird ein "Dummy-Readout" empfohlen, man liest
 239            also einen Wert und verwirft diesen, um den ADC "warmlaufen zu lassen" */
 240         ADCSRA |= (1<<ADSC);              // eine ADC-Wandlung
 241         while ( ADCSRA & (1<<ADSC)  ) {
 242                      // auf Abschluss der Konvertierung warten
 243         }
 244         result = ADCW;  // ADCW muss einmal gelesen werden,
 245         // sonst wird Ergebnis der nächsten Wandlung
 246         // nicht übernommen.
 247
 248         /* Eigentliche Messung - Mittelwert aus 5 aufeinanderfolgenden Wandlungen */
 249         result = 0;
 250         for( i=0; i<5; i++ )
 251         {
 252                 ADCSRA |= (1<<ADSC);            // eine Wandlung "single conversion"
 253                 while ( ADCSRA & (1<<ADSC) ) {
 254                            // auf Abschluss der Konvertierung warten
 255                 }
 256                 result += ADCW;             // Wandlungsergebnisse aufaddieren
 257         }
 258
 259         ADCSRA &= ~(1<<ADEN);             // ADC deaktivieren (2)
 260
 261         result /= 5;                     // Summe durch 5 teilen = arithm. Mittelwert
 262
 263         return result;
 264 }
 265
 266
 267 static unsigned short get_distance(uint8_t i) {
 268         return ReadChannel(i);
 269 }
 270
 271
 272 static unsigned short get_voltage(void) {
 273         return ReadChannel(2)*1.46;
 274 }
 275
 276
 277 /*
 278  * zero offset: 0.5V
 279  * sensitivity: 133mV/A
 280  */
 281 static unsigned short get_current(void) {
 282         double volt = ReadChannel(3)*5.0171; // mV
 283         return (volt-517.78)/0.12656; // mA
 284 }
 285
 286
 287 ISR(INT0_vect) {
 288         static uint16_t t_start=0;
 289         uint16_t t_now = TCNT1;
 290         uint16_t t_diff;
 291
 292         if (bit_is_set(PIND, 2)) { // high level
 293                 // start timer
 294                 t_start = t_now;
 295         } else {
 296                 t_diff = t_now - t_start;
 297                 dist_forward1 = t_diff*2.7586 + 0.5; // t [µs] / 580 = mm
 298                 // disable this interrupt
 299                 EIMSK &= ~(1 << INT0);
 300         }
 301 }
 302
 303
 304 ISR(INT1_vect) {
 305         static uint16_t t_start=0;
 306         uint16_t t_now = TCNT1;
 307         uint16_t t_diff;
 308
 309         if (bit_is_set(PIND, 3)) { // high level
 310                 // start timer
 311                 t_start = t_now;
 312         } else {
 313                 t_diff = t_now - t_start;
 314                 dist_backward = t_diff*2.7586 + 0.5; // t [µs] / 580 = mm
 315                 // disable this interrupt
 316                 EIMSK &= ~(1 << INT1);
 317         }
 318 }
 319
 320
 321 ISR(PCINT2_vect) {
 322         uint8_t pind_cur = PIND;
 323
 324         if ((pind_cur ^ pind_pre) & (1<<4)) { // PCINT20
 325                 static uint16_t t_start=0;
 326                 uint16_t t_now = TCNT1;
 327                 uint16_t t_diff;
 328
 329                 if (bit_is_set(pind_cur, 4)) { // high level
 330                         // start timer
 331                         t_start = t_now;
 332                 } else {
 333                         t_diff = t_now - t_start;
 334                         dist_forward2 = t_diff*2.7586 + 0.5; // t [µs] / 580 = mm
 335                         // disable this interrupt
 336                         PCMSK2 &= ~(1 << PCINT20);
 337                 }
 338         }
 339
 340         pind_pre = pind_cur;
 341 }
 342
 343
 344 int main(void) {
 345         bootloader = 0x00;
 346         setup_uart(9600);
 347         uart_setup_stdout();
 348
 349         // I2C
 350         TWAR = 0x52;
 351         TWI_ACK;
 352
 353         // Timer 1: Normal mode, Top: 0xffff, Prescaler: F_CPU/256=62500Hz
 354         TCCR1A = 0x0;
 355         TCCR1B = (1 << CS12);
 356
 357         // External Interrupts
 358         EICRA = (1 << ISC10) | (1 << ISC00);
 359         PCICR = (1 << PCIE2);
 360
 361         printf_P(PSTR("\r\nStart\r\n"));
 362
 363         set_sleep_mode(SLEEP_MODE_IDLE);
 364         sei();
 365         while(1) {
 366                 switch(ireg) {
 367                         case 0x01: // ir left
 368                                 dist_left = get_distance(0);
 369                                 break;
 370                         case 0x03: // ir right
 371                                 dist_right = get_distance(1);
 372                                 break;
 373                         case 0x09: // voltage
 374                                 voltage = get_voltage();
 375                                 break;
 376                         case 0x0d: // current
 377                                 current = get_current();
 378                                 break;
 379                         case 0xff: // Magic reg that starts the bootloader
 380                                 if (bootloader == 0xa5) {
 381                                         cli();
 382                                         // write mark to first area in eeprom
 383                                         eeprom_write_byte((uint8_t*)0, 123);
 384                                         eeprom_busy_wait();
 385                                         // Use watchdog to restart
 386                                         wdt_enable(WDTO_15MS);
 387                                 }
 388                                 break;
 389                 }
 390
 391                 if (start_dist_fwd1) {
 392                         start_dist_fwd1 = 0;
 393                         dist_forward1 = 0;
 394
 395                         DDRD |= (1 << 2);
 396                         PORTD |= (1 << 2);
 397                         _delay_us(10);
 398                         PORTD &= ~(1 << 2);
 399                         DDRD &= ~(1 << 2);
 400                         // wait for interrupt
 401                         EIFR &= (1 << INTF0); // clear old interrupt before enabling
 402                         EIMSK |= (1 << INT0);
 403                 }
 404                 if (start_dist_bwd) {
 405                         start_dist_bwd = 0;
 406                         dist_backward = 0;
 407
 408                         DDRD |= (1 << 3);
 409                         PORTD |= (1 << 3);
 410                         _delay_us(10);
 411                         PORTD &= ~(1 << 3);
 412                         DDRD &= ~(1 << 3);
 413                         // wait for interrupt
 414                         EIFR &= (1 << INTF1); // clear old interrupt before enabling
 415                         EIMSK |= (1 << INT1);
 416                 }
 417                 if (start_dist_fwd2) {
 418                         start_dist_fwd2 = 0;
 419                         dist_forward2 = 0;
 420
 421                         // PD4 = PCINT20
 422                         DDRD |= (1 << 4);
 423                         PORTD |= (1 << 4);
 424                         _delay_us(10);
 425                         PORTD &= ~(1 << 4);
 426                         DDRD &= ~(1 << 4);
 427                         // wait for interrupt
 428                         pind_pre = PIND;
 429                         PCMSK2 |= (1 << PCINT20);
 430                 }
 431
 432                 sleep_mode();
 433         }
 434
 435         return 0;
 436 }