aircon/firmware/main.c

   1 /*
   2  *      Air Conditioning Controller
   3  *
   4  *      (c) 2019 Martin Mareš <mj@ucw.cz>
   5  */
   6
   7 #include "util.h"
   8 #include "ds18b20.h"
   9 #include "modbus.h"
  10 #include "registers.h"
  11
  12 #include <libopencm3/cm3/nvic.h>
  13 #include <libopencm3/cm3/systick.h>
  14 #include <libopencm3/stm32/rcc.h>
  15 #include <libopencm3/stm32/gpio.h>
  16 #include <libopencm3/stm32/timer.h>
  17 #include <libopencm3/stm32/usart.h>
  18
  19 #include <string.h>
  20
  21 static void rc_init(void);
  22 static bool rc_send(char key);
  23
  24 static void clock_init(void)
  25 {
  26         rcc_clock_setup_in_hse_8mhz_out_72mhz();
  27
  28         rcc_periph_clock_enable(RCC_GPIOA);
  29         rcc_periph_clock_enable(RCC_GPIOB);
  30         rcc_periph_clock_enable(RCC_GPIOC);
  31         rcc_periph_clock_enable(RCC_USART1);
  32         rcc_periph_clock_enable(RCC_USART3);
  33         rcc_periph_clock_enable(RCC_TIM1);
  34         rcc_periph_clock_enable(RCC_TIM2);
  35         rcc_periph_clock_enable(RCC_TIM3);
  36         rcc_periph_clock_enable(RCC_TIM4);
  37         rcc_periph_clock_enable(RCC_DMA1);
  38
  39         rcc_periph_reset_pulse(RST_GPIOA);
  40         rcc_periph_reset_pulse(RST_GPIOB);
  41         rcc_periph_reset_pulse(RST_GPIOC);
  42         rcc_periph_reset_pulse(RST_USART1);
  43         rcc_periph_reset_pulse(RST_USART3);
  44         rcc_periph_reset_pulse(RST_TIM1);
  45         rcc_periph_reset_pulse(RST_TIM2);
  46         rcc_periph_reset_pulse(RST_TIM3);
  47         rcc_periph_reset_pulse(RST_TIM4);
  48 }
  49
  50 static void gpio_init(void)
  51 {
  52         // Switch JTAG off to free up pins
  53         gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON, 0);
  54
  55         // PA6 = RS485 TX enable
  56         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO6);
  57         gpio_clear(GPIOA, GPIO6);
  58
  59         // PA7 = TIM3_CH2 for DS18B20 bus -- configured by ds18b20 library
  60
  61         // PA9 = TXD1 for debugging console
  62         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
  63
  64         // PA10 = RXD1 for debugging console
  65         gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO10);
  66
  67         // PB0 = bypass LED*
  68         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO0);
  69         gpio_set(GPIOB, GPIO0);
  70
  71         // PB1 = MODBUS frame LED*
  72         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO1);
  73         gpio_set(GPIOB, GPIO1);
  74
  75         // PB6 = TIM4_CH1 fan control opto-coupler
  76         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO6);
  77
  78         // PB7 = TIM4_CH2 IR LED
  79         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, GPIO7);
  80
  81         // PB10 = TXD3 for RS485
  82         gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO10);
  83
  84         // PB11 = RXD3 for RS485
  85         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO11);
  86
  87         // PC13 = BluePill LED
  88         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
  89         gpio_clear(GPIOC, GPIO13);
  90
  91         // PC15 = bypass opto-coupler
  92         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO15);
  93         gpio_clear(GPIOC, GPIO15);
  94 }
  95
  96 static volatile u32 ms_ticks;
  97
  98 void sys_tick_handler(void)
  99 {
 100         ms_ticks++;
 101 }
 102
 103 static void tick_init(void)
 104 {
 105         systick_set_frequency(1000, 72000000);
 106         systick_counter_enable();
 107         systick_interrupt_enable();
 108 }
 109
 110 #if 0
 111 static void delay_ms(uint ms)
 112 {
 113         u32 start_ticks = ms_ticks;
 114         while (ms_ticks - start_ticks < ms)
 115                 ;
 116 }
 117 #endif
 118
 119 static void usart_init(void)
 120 {
 121         usart_set_baudrate(USART1, 115200);
 122         usart_set_databits(USART1, 8);
 123         usart_set_stopbits(USART1, USART_STOPBITS_1);
 124         usart_set_mode(USART1, USART_MODE_TX_RX);
 125         usart_set_parity(USART1, USART_PARITY_NONE);
 126         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
 127
 128         usart_enable(USART1);
 129 }
 130
 131 // TIM4 will run on CPU clock, it will overflow with frequency 38 kHz (IR modulation frequency)
 132 #define T4_CYCLE ((CPU_CLOCK_MHZ * 1000000 + 37999) / 38000)
 133
 134 static byte bypass_active;
 135 static byte fan_pwm;
 136
 137 static void show_temperature(void)
 138 {
 139         debug_putc('#');
 140         for (uint i=0; ds_sensors[i].address[0]; i++) {
 141                 debug_putc(' ');
 142                 int t = ds_sensors[i].current_temp;
 143                 if (t == DS_TEMP_UNKNOWN)
 144                         debug_puts("---.---");
 145                 else
 146                         debug_printf("%3d.%03d", t / 1000, t % 1000);
 147         }
 148         debug_printf(" %d", bypass_active);
 149         debug_printf(" %d", fan_pwm);
 150         debug_puts("\r\n");
 151 }
 152
 153 static void pwm_init(void)
 154 {
 155         timer_set_prescaler(TIM4, 0);
 156         timer_set_mode(TIM4, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
 157         timer_disable_preload(TIM4);
 158         timer_set_period(TIM4, T4_CYCLE - 1);
 159
 160         // 50% PWM for the IR LED
 161         timer_set_oc_mode(TIM4, TIM_OC2, TIM_OCM_FORCE_HIGH);   // will be TIM_OCM_PWM1 when transmitting
 162         timer_set_oc_value(TIM4, TIM_OC2, T4_CYCLE / 2);
 163         timer_set_oc_polarity_high(TIM4, TIM_OC2);
 164         timer_enable_oc_output(TIM4, TIM_OC2);
 165
 166         // PWM for controlling fan
 167         timer_set_oc_mode(TIM4, TIM_OC1, TIM_OCM_PWM1);
 168         timer_set_oc_value(TIM4, TIM_OC1, 0);
 169         timer_set_oc_polarity_high(TIM4, TIM_OC1);
 170         timer_enable_oc_output(TIM4, TIM_OC1);
 171
 172         timer_enable_counter(TIM4);
 173 }
 174
 175 int main(void)
 176 {
 177         clock_init();
 178         gpio_init();
 179         tick_init();
 180         usart_init();
 181         pwm_init();
 182         rc_init();
 183
 184         debug_puts("Hello, world! This is Aircon Controller speaking.\n");
 185
 186         ds_init();
 187         modbus_init();
 188
 189         u32 last_show_temp = 0;
 190         u32 last_ds_step = 0;
 191
 192         for (;;) {
 193                 if (ms_ticks - last_ds_step >= 100) {
 194                         debug_led_toggle();
 195                         ds_step();
 196                         last_ds_step = ms_ticks;
 197                 }
 198
 199                 modbus_loop();
 200
 201                 if (usart_get_flag(USART1, USART_SR_RXNE)) {
 202                         uint ch = usart_recv(USART1);
 203                         if (ch == 'B') {
 204                                 bypass_active = 1;
 205                                 gpio_set(GPIOC, GPIO15);        // opto-coupler
 206                                 gpio_clear(GPIOB, GPIO0);       // LED
 207                         } else if (ch == 'b') {
 208                                 bypass_active = 0;
 209                                 gpio_clear(GPIOC, GPIO15);      // opto-coupler
 210                                 gpio_set(GPIOB, GPIO0);         // LED
 211                         } else if (ch >= '0' && ch <= '9') {
 212                                 fan_pwm = 3*(ch - '0') + 1;
 213                                 /*
 214                                  *      ch      pwm       %
 215                                  *      0         1       0
 216                                  *      1         4       0
 217                                  *      2         7      18
 218                                  *      3        10      31
 219                                  *      4        13      44
 220                                  *      5        16      57
 221                                  *      6        19      71
 222                                  *      7        22      84
 223                                  *      8        25      97
 224                                  *      9        28     100
 225                                  *
 226                                  *      % = pwm*4.389 - 12.723
 227                                  */
 228                                 timer_set_oc_value(TIM4, TIM_OC1, T4_CYCLE * fan_pwm / 256);
 229                         } else {
 230                                 rc_send(ch);
 231                         }
 232                 }
 233
 234                 if (ms_ticks - last_show_temp >= 5000) {
 235                         show_temperature();
 236                         last_show_temp = ms_ticks;
 237                 }
 238
 239                 wait_for_interrupt();
 240         }
 241
 242         return 0;
 243 }
 244
 245 /*** Infra-red remote control transmitter ***/
 246
 247 enum rc_keys {
 248         RC_AUTO,
 249         RC_TEMP_UP,
 250         RC_FUNC,
 251         RC_HI,
 252         RC_TIMER,
 253         RC_MID,
 254         RC_TEMP_DOWN,
 255         RC_SLEEP,
 256         RC_LOW,
 257         RC_POWER,
 258         RC_MAX
 259 };
 260
 261 static const char * const rc_patterns[RC_MAX] = {
 262         [RC_AUTO]       = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*A*B*B*A*B*A*A*B*B*A*A*B*A*B*B*A*$",
 263         [RC_TEMP_UP]    = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*A*A*B*A*B*A*A*B*B*B*A*B*A*B*B*A*$",
 264         [RC_FUNC]       = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*B*A*B*B*B*A*A*B*A*B*A*A*A*B*B*A*$",
 265         [RC_HI]         = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*B*A*A*B*B*A*A*B*A*B*B*A*A*B*B*A*$",
 266         [RC_TIMER]      = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*A*B*B*B*B*A*A*B*B*A*A*A*A*B*B*A*$",
 267         [RC_MID]        = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*B*B*A*B*B*A*A*B*A*A*B*A*A*B*B*A*$",
 268         [RC_TEMP_DOWN]  = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*B*A*B*A*B*A*A*B*A*B*A*B*A*B*B*A*$",
 269         [RC_SLEEP]      = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*B*B*B*B*B*A*A*B*A*A*A*A*A*B*B*A*$",
 270         [RC_LOW]        = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*A*B*A*B*B*A*A*B*B*A*B*A*A*B*B*A*$",
 271         [RC_POWER]      = "^#*A*A*A*A*A*A*A*B*B*B*B*B*B*B*B*A*A*A*B*B*B*A*A*B*B*B*A*A*A*B*B*A*$",
 272 };
 273
 274 static const char rc_keys[] = "aufhtmdslp";
 275
 276 static void rc_init(void)
 277 {
 278         // TIM1 runs at 1 MHz and it is used for timing of RC pulses
 279         timer_set_prescaler(TIM1, CPU_CLOCK_MHZ - 1);
 280         timer_set_mode(TIM1, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
 281         timer_update_on_overflow(TIM1);
 282         timer_disable_preload(TIM1);
 283         timer_one_shot_mode(TIM1);
 284         timer_enable_irq(TIM1, TIM_DIER_UIE);
 285         nvic_enable_irq(NVIC_TIM1_UP_IRQ);
 286 }
 287
 288 static volatile const char *rc_pattern_pos;
 289 static volatile char rc_pending;
 290
 291 void tim1_up_isr(void)
 292 {
 293         if (TIM_SR(TIM1) & TIM_SR_UIF) {
 294                 TIM_SR(TIM1) &= ~TIM_SR_UIF;
 295
 296                 if (!rc_pattern_pos)    // Just to be sure
 297                         return;
 298
 299                 bool val;       // 1=pulse, 0=break
 300                 uint duration;  // in μs
 301
 302                 switch (*rc_pattern_pos++) {
 303                         case '^':
 304                                 val = 1;
 305                                 duration = 9032;
 306                                 break;
 307                         case '#':
 308                                 val = 0;
 309                                 duration = 4457;
 310                                 break;
 311                         case '*':
 312                                 val = 1;
 313                                 duration = 619;
 314                                 break;
 315                         case 'A':
 316                                 val = 0;
 317                                 duration = 514;
 318                                 break;
 319                         case 'B':
 320                                 val = 0;
 321                                 duration = 1617;
 322                                 break;
 323                         case '$':
 324                                 val = 0;
 325                                 duration = 10000;
 326                                 break;
 327                         default:
 328                                 // End of transmission
 329                                 gpio_set(GPIOC, GPIO13);
 330                                 rc_pattern_pos = NULL;
 331                                 rc_pending = 0;
 332                                 return;
 333                 }
 334
 335                 if (val)
 336                         timer_set_oc_mode(TIM4, TIM_OC2, TIM_OCM_PWM1);
 337                 else
 338                         timer_set_oc_mode(TIM4, TIM_OC2, TIM_OCM_FORCE_HIGH);
 339
 340                 timer_set_period(TIM1, duration - 1);
 341                 timer_generate_event(TIM1, TIM_EGR_UG);
 342                 timer_enable_counter(TIM1);
 343         }
 344 }
 345
 346 static bool rc_send(char key)
 347 {
 348         if (rc_pending)
 349                 return false;
 350
 351         const char *s = strchr(rc_keys, key);
 352         if (!s)
 353                 return false;
 354         rc_pending = key;
 355         rc_pattern_pos = rc_patterns[s - rc_keys];
 356         debug_printf("RC sending: %c", key);
 357
 358         gpio_clear(GPIOC, GPIO13);
 359
 360         timer_set_period(TIM1, 1);
 361         timer_generate_event(TIM1, TIM_EGR_UG);
 362         timer_enable_counter(TIM1);
 363         return true;
 364 }
 365
 366 /*** Modbus callbacks ***/
 367
 368 bool modbus_check_discrete_input(u16 addr UNUSED)
 369 {
 370         return false;
 371 }
 372
 373 bool modbus_get_discrete_input(u16 addr UNUSED)
 374 {
 375         return false;
 376 }
 377
 378 bool modbus_check_coil(u16 addr)
 379 {
 380         return addr < AIRCON_COIL_MAX;
 381 }
 382
 383 bool modbus_get_coil(u16 addr)
 384 {
 385         switch (addr) {
 386         case AIRCON_COIL_EXCHANGER_BYPASS:
 387                 return bypass_active;
 388         default:
 389                 return false;
 390         }
 391 }
 392
 393 void modbus_set_coil(u16 addr, bool value)
 394 {
 395         switch (addr) {
 396         case AIRCON_COIL_EXCHANGER_BYPASS:
 397                 bypass_active = value;
 398                 if (bypass_active) {
 399                         gpio_set(GPIOC, GPIO15);        // opto-coupler
 400                         gpio_clear(GPIOB, GPIO0);       // LED
 401                 } else {
 402                         gpio_clear(GPIOC, GPIO15);      // opto-coupler
 403                         gpio_set(GPIOB, GPIO0);         // LED
 404                 }
 405                 break;
 406         default:
 407                 ;
 408         }
 409 }
 410
 411 #define AIRCON_IREG_DS_ID_MAX (AIRCON_IREG_DS_ID_BASE + 3*DS_NUM_SENSORS)
 412
 413 bool modbus_check_input_register(u16 addr)
 414 {
 415         return (addr < AIRCON_IREG_MAX || addr >= AIRCON_IREG_DS_ID_BASE && addr < AIRCON_IREG_DS_ID_BASE);
 416 }
 417
 418 static const byte temp_sensor_addrs[][8] = {
 419         { 0xAA, 0x36, 0x69, 0x19, 0x13, 0x02 },
 420         { 0x4A, 0x1B, 0x79, 0x97, 0x01, 0x03 },
 421         { 0xAA, 0xAC, 0xD9, 0x18, 0x13, 0x02 },
 422         { 0x30, 0x66, 0x79, 0x97, 0x08, 0x03 },
 423         { 0xAA, 0x02, 0x64, 0x19, 0x13, 0x02 },
 424 };
 425
 426 u16 modbus_get_input_register(u16 addr)
 427 {
 428         if (addr <= AIRCON_IREG_TEMP_MIXED) {
 429                 byte i = 0;
 430                 while (i < DS_NUM_SENSORS && memcmp(ds_sensors[i].address + 1, temp_sensor_addrs[addr], 6))
 431                         i++;
 432                 if (i >= DS_NUM_SENSORS)
 433                         return 0x8000;
 434                 if (ds_sensors[i].current_temp == DS_TEMP_UNKNOWN)
 435                         return 0x8000;
 436                 return ((ds_sensors[i].current_temp + 5) / 10) & 0xffff;
 437         } else if (addr >= AIRCON_IREG_DS_ID_BASE && addr < AIRCON_IREG_DS_ID_MAX) {
 438                 byte i = (addr - AIRCON_IREG_DS_ID_BASE) / 3;
 439                 byte j = (addr - AIRCON_IREG_DS_ID_BASE) % 3;
 440                 return get_u16_be(ds_sensors[i].address + 2*j + 1);
 441         } else {
 442                 return 0;
 443         }
 444 }
 445
 446 bool modbus_check_holding_register(u16 addr)
 447 {
 448         return addr < AIRCON_HREG_MAX;
 449 }
 450
 451 u16 modbus_get_holding_register(u16 addr)
 452 {
 453         switch (addr) {
 454         case AIRCON_HREG_EXCHANGER_FAN:
 455                 return fan_pwm;
 456         case AIRCON_HREG_REMOTE_CONTROL:
 457                 return rc_pending;
 458         default:
 459                 return 0;
 460         }
 461 }
 462
 463 void modbus_set_holding_register(u16 addr, u16 value)
 464 {
 465         switch (addr) {
 466         case AIRCON_HREG_EXCHANGER_FAN:
 467                 fan_pwm = MIN(value, 255);
 468                 timer_set_oc_value(TIM4, TIM_OC1, T4_CYCLE * fan_pwm / 256);
 469                 break;
 470         case AIRCON_HREG_REMOTE_CONTROL:
 471                 if (!rc_send(value))
 472                         modbus_slave_error();
 473                 break;
 474         default:
 475                 ;
 476         }
 477 }
 478
 479 void modbus_ready_hook(void)
 480 {
 481         // Frame LED off
 482         gpio_set(GPIOB, GPIO1);
 483 }
 484
 485 void modbus_frame_start_hook(void)
 486 {
 487         // Frame LED on
 488         gpio_clear(GPIOB, GPIO1);
 489 }
 490
 491 const char * const modbus_id_strings[MODBUS_ID_MAX] = {
 492         [MODBUS_ID_VENDOR_NAME] = "United Computer Wizards",
 493         [MODBUS_ID_PRODUCT_CODE] = "42",
 494         [MODBUS_ID_MAJOR_MINOR_REVISION] = "1.0",
 495         [MODBUS_ID_VENDOR_URL] = "http://www.ucw.cz/",
 496         [MODBUS_ID_PRODUCT_NAME] = "Magic Gadget",
 497         [MODBUS_ID_USER_APP_NAME] = NULL,
 498 };