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