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