test-sinclair/main.c

   1 /*
   2  *      Testing Communication with Sinclair Air Conditioner
   3  *
   4  *      (c) 2023 Martin Mareš <mj@ucw.cz>
   5  */
   6
   7 #include "util.h"
   8
   9 #include <libopencm3/cm3/cortex.h>
  10 #include <libopencm3/cm3/nvic.h>
  11 #include <libopencm3/cm3/systick.h>
  12 #include <libopencm3/cm3/scb.h>
  13 #include <libopencm3/stm32/rcc.h>
  14 #include <libopencm3/stm32/desig.h>
  15 #include <libopencm3/stm32/gpio.h>
  16 #include <libopencm3/stm32/usart.h>
  17 #include <libopencm3/stm32/spi.h>
  18 #include <libopencm3/stm32/timer.h>
  19 #include <libopencm3/usb/dfu.h>
  20 #include <libopencm3/usb/usbd.h>
  21
  22 #include <string.h>
  23
  24 /*** Hardware init ***/
  25
  26 static void clock_init(void)
  27 {
  28         rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
  29
  30         rcc_periph_clock_enable(RCC_GPIOA);
  31         rcc_periph_clock_enable(RCC_GPIOB);
  32         rcc_periph_clock_enable(RCC_GPIOC);
  33         rcc_periph_clock_enable(RCC_SPI2);
  34         rcc_periph_clock_enable(RCC_USART1);
  35         rcc_periph_clock_enable(RCC_USB);
  36         rcc_periph_clock_enable(RCC_TIM3);
  37         rcc_periph_clock_enable(RCC_TIM4);
  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_SPI2);
  43         rcc_periph_reset_pulse(RST_USART1);
  44         rcc_periph_reset_pulse(RST_USB);
  45         rcc_periph_reset_pulse(RST_TIM3);
  46         rcc_periph_reset_pulse(RST_TIM4);
  47 }
  48
  49 static void gpio_init(void)
  50 {
  51         // PA9 = TXD1 for debugging console
  52         // PA10 = RXD1 for debugging console
  53         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
  54         gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO10);
  55
  56         // PC13 = BluePill LED
  57         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
  58         gpio_clear(GPIOC, GPIO13);
  59
  60         // PB13 = SCK2
  61         // PB15 = MOSI2
  62         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO13);
  63         gpio_set_mode(GPIOB, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO15);
  64
  65         // PA8 = IR remote control
  66         gpio_clear(GPIOA, GPIO8);
  67         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8);
  68 }
  69
  70 static void usart_init(void)
  71 {
  72         usart_set_baudrate(USART1, 115200);
  73         usart_set_databits(USART1, 8);
  74         usart_set_stopbits(USART1, USART_STOPBITS_1);
  75         usart_set_mode(USART1, USART_MODE_TX_RX);
  76         usart_set_parity(USART1, USART_PARITY_NONE);
  77         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
  78
  79         usart_enable(USART1);
  80 }
  81
  82 /*** System ticks ***/
  83
  84 static volatile u32 ms_ticks;
  85
  86 void sys_tick_handler(void)
  87 {
  88         ms_ticks++;
  89 }
  90
  91 static void tick_init(void)
  92 {
  93         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
  94         systick_counter_enable();
  95         systick_interrupt_enable();
  96 }
  97
  98 static void delay_ms(uint ms)
  99 {
 100         u32 start_ticks = ms_ticks;
 101         while (ms_ticks - start_ticks < ms)
 102                 ;
 103 }
 104
 105 /*** Emulated TM1618 LED Driver ***/
 106
 107 /*
 108  *  Theory of operation:
 109  *
 110  *  TM1618 communicates using a bi-directional SPI-like protocol.
 111  *  The AC unit is sending a stream of commands like this once per ca. 4 ms:
 112  *
 113  *      00 - set mode: 4 grids, 8 segments
 114  *      44 - will write to display memory, no auto-increment
 115  *      Cx - set memory address to x
 116  *      yy - data to write, two most-significant bits are always zero
 117  *      8B - display ON, duty cycle 10/16
 118  *
 119  *  No read commands are issued, so we can simulate TM1618 using a pure SPI slave.
 120  *
 121  *  Commands are delimited using the STB* (strobe) pin, but since our opto-couplers
 122  *  are negating, we cannot route this pin to SS (slave select) of our SPI.
 123  *  We tried triggering an external interrupt by this pin, but it turned out
 124  *  that the latency is too high.
 125  *
 126  *  Instead, we ignore STB* completely and implement a self-synchronizing receiver:
 127  *
 128  *    - The only byte which can have top 2 bits both set is the Cx command,
 129  *      so we can use this to find memory addresses and data in the stream.
 130  *      We can ignore all other commands.
 131  *
 132  *    - Whenever 1 ms passes since the last byte was received, we reset the SPI.
 133  *      This allows us to recover from misaligned bytes.
 134  */
 135
 136 static void tm_init(void)
 137 {
 138         // Configure SPI2 to receive
 139         spi_set_receive_only_mode(SPI2);
 140         spi_enable_software_slave_management(SPI2);
 141         spi_set_nss_low(SPI2);
 142         spi_send_lsb_first(SPI2);
 143         spi_set_clock_polarity_0(SPI2);
 144         spi_set_clock_phase_1(SPI2);
 145         spi_enable_rx_buffer_not_empty_interrupt(SPI2);
 146         nvic_enable_irq(NVIC_SPI2_IRQ);
 147         spi_enable(SPI2);
 148
 149         // TIM3 will handle receive timeout
 150         timer_set_prescaler(TIM3, CPU_CLOCK_MHZ-1);     // 1 tick = 1 μs
 151         timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
 152         timer_update_on_overflow(TIM3);
 153         timer_disable_preload(TIM3);
 154         timer_one_shot_mode(TIM3);
 155         timer_enable_irq(TIM3, TIM_DIER_UIE);
 156         nvic_enable_irq(NVIC_TIM3_IRQ);
 157 }
 158
 159 /*
 160  *  Data memory of TM1618:
 161  *
 162  *  [0]    .    .    .    -    -    -    -    -
 163  *  [1]    .    .    -    -    HEAT .    .    .
 164  *  [2]    .    .    .    DRY  -    SLP  MED  LOW
 165  *  [3]    .    .    HIGH AUTO COOL .    .    .
 166  *  [4]    .    .    .    B2   -    G2   D2   C2
 167  *  [5]    .    .    E2   F2   A2   .    .    .
 168  *  [6]    .    .    .    B1   -    G1   D1   C1
 169  *  [7]    .    .    E1   F1   A1   .    .    .
 170  *
 171  *  "." is an always-zero bit not defined by TM1618, "-" is defined, but not used by AC.
 172  */
 173 static volatile byte tm_data[8];
 174 static volatile uint tm_overruns;
 175
 176 static volatile byte tm_buffer[256];
 177 static volatile uint tm_len;
 178
 179 /*
 180  *
 181  *  Display segments:
 182  *
 183  *      +--A--+
 184  *      |     |
 185  *      F     B
 186  *      |     |
 187  *      +--G--+
 188  *      |     |
 189  *      E     C
 190  *      |     |
 191  *      +--D--+
 192  */
 193
 194 enum tm_seg {
 195         SEGa = 0x0800,
 196         SEGb = 0x0010,
 197         SEGc = 0x0001,
 198         SEGd = 0x0002,
 199         SEGe = 0x2000,
 200         SEGf = 0x1000,
 201         SEGg = 0x0004,
 202 };
 203
 204 static const u16 tm_digits[10] = {
 205         [0] = SEGa | SEGb | SEGc | SEGd | SEGe | SEGf,
 206         [1] = SEGb | SEGc,
 207         [2] = SEGa | SEGb | SEGd | SEGe | SEGg,
 208         [3] = SEGa | SEGb | SEGc | SEGd | SEGg,
 209         [4] = SEGb | SEGc | SEGf | SEGg,
 210         [5] = SEGa | SEGc | SEGd | SEGf | SEGg,
 211         [6] = SEGa | SEGc | SEGd | SEGe | SEGf | SEGg,
 212         [7] = SEGa | SEGb | SEGc,
 213         [8] = SEGa | SEGb | SEGc | SEGd | SEGe | SEGf | SEGg,
 214         [9] = SEGa | SEGb | SEGc | SEGd | SEGf | SEGg,
 215 };
 216
 217 static volatile uint tm_timeouts;
 218
 219 void spi2_isr(void)
 220 {
 221         if (SPI_SR(SPI2) & SPI_SR_OVR)
 222                 tm_overruns++;
 223         if (SPI_SR(SPI2) & SPI_SR_RXNE) {
 224                 byte x = SPI_DR(SPI2) ^ 0xff;
 225 #if 0
 226                 if (tm_len < ARRAY_SIZE(tm_buffer))
 227                         tm_buffer[tm_len++] = x;
 228 #endif
 229                 static byte tm_address;
 230                 if (tm_address) {
 231                         tm_data[tm_address & 7] = x;
 232                         tm_address = 0;
 233                 } else if ((x & 0xc0) == 0xc0) {
 234                         tm_address = x;
 235                 }
 236                 timer_set_period(TIM3, 999);
 237                 timer_generate_event(TIM3, TIM_EGR_UG);
 238                 timer_enable_counter(TIM3);
 239         }
 240 }
 241
 242 void tim3_isr(void)
 243 {
 244         if (TIM_SR(TIM3) & TIM_SR_UIF) {
 245                 TIM_SR(TIM3) &= ~TIM_SR_UIF;
 246                 tm_timeouts++;
 247                 spi_set_nss_high(SPI2);
 248                 spi_set_nss_low(SPI2);
 249         }
 250 }
 251
 252 static void tm_show(void)
 253 {
 254         debug_printf("TM:");
 255         for (uint i=0; i<8; i++)
 256                 debug_printf(" %02x", tm_data[i]);
 257         debug_printf(" o=%d t=%d", tm_overruns, tm_timeouts);
 258
 259         debug_printf(" =>");
 260         if (tm_data[1] & 0x08)
 261                 debug_printf(" HEAT");
 262         if (tm_data[2] & 0x10)
 263                 debug_printf(" DRY");
 264         if (tm_data[2] & 0x04)
 265                 debug_printf(" SLEEP");
 266         if (tm_data[2] & 0x02)
 267                 debug_printf(" MED");
 268         if (tm_data[2] & 0x01)
 269                 debug_printf(" LOW");
 270         if (tm_data[3] & 0x20)
 271                 debug_printf(" HIGH");
 272         if (tm_data[3] & 0x10)
 273                 debug_printf(" AUTO");
 274         if (tm_data[3] & 0x08)
 275                 debug_printf(" COOL");
 276
 277         debug_putc(' ');
 278         for (int i=0; i<2; i++) {
 279                 uint x = (tm_data[7-2*i] << 8) | tm_data[6-2*i];
 280                 uint j = 0;
 281                 while (j < 10 && tm_digits[j] != x)
 282                         j++;
 283                 if (j == 10)
 284                         debug_putc('?');
 285                 else
 286                         debug_putc('0' + j);
 287         }
 288
 289         debug_putc('\n');
 290
 291 #if 0
 292         static byte tm_dumped;
 293         if (!tm_dumped && tm_len == ARRAY_SIZE(tm_buffer)) {
 294                 for (uint i=0; i < tm_len; i++)
 295                         debug_printf("%02x ", tm_buffer[i]);
 296                 debug_putc('\n');
 297                 // tm_dumped = 1;
 298                 tm_len = 0;
 299         }
 300 #endif
 301 }
 302
 303 /*** Infra-red remote control simulator ***/
 304
 305 /*
 306  *  The AC unit expects demodulated IR signal. The RC sends 52-bit messages
 307  *  (plus leader and trailer). The last 4 bits are a complement of checksum
 308  *  of 4-bit nibbles.
 309  */
 310
 311 #define RC_POWER_OFF_HI         0b00000000000000000000
 312 #define RC_POWER_OFF_LO         0b00000000000000010000000010100100
 313
 314 #define RC_DEFAULT_HI           0b00000011000000000000
 315
 316 // Combines with a temperature setting (17-30)
 317 #define RC_COOL_AUTO            0b00000000000000010000000000000000
 318 #define RC_COOL_HI              0b00000000000000010000100000000000
 319 #define RC_COOL_MED             0b00000000000000010001000100000000
 320 #define RC_COOL_LO              0b00000000000000010010001000000000
 321
 322 static const u32 rc_cool_fan[4] = {
 323         RC_COOL_AUTO,
 324         RC_COOL_LO,
 325         RC_COOL_MED,
 326         RC_COOL_HI,
 327 };
 328
 329 // Combines with a temperature setting (15-25)
 330 #define RC_WARM                 0b00000000000000010000001100000000
 331
 332 // This is sent with temperature=17
 333 #define RC_DEHUMIDIFY           0b00000000000000010010010000000000
 334
 335 // This can be added to any command to enable sleep mode, but we do not issue these yet
 336 #define RC_SLEEP                0b00000000000010000000000000000000
 337
 338 enum rc_mode {
 339         MODE_OFF,
 340         MODE_COOL,
 341         MODE_WARM,
 342         MODE_DEHUMIDIFY,
 343 };
 344
 345 static byte rc_mode = MODE_COOL;        // MODE_xxx
 346 static byte rc_fan;                     // 0-3
 347 static byte rc_temp = 17;               // 15-30
 348
 349 static void rc_init(void)
 350 {
 351         // TIM4 runs at 1 MHz and it is used for timing of RC pulses
 352         timer_set_prescaler(TIM4, CPU_CLOCK_MHZ - 1);
 353         timer_set_mode(TIM4, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
 354         timer_update_on_overflow(TIM4);
 355         timer_disable_preload(TIM4);
 356         timer_one_shot_mode(TIM4);
 357         timer_enable_irq(TIM4, TIM_DIER_UIE);
 358         nvic_enable_irq(NVIC_TIM4_IRQ);
 359 }
 360
 361 static u32 rc_pattern[2];
 362 static uint rc_tick;
 363
 364 static void rc_encode(void)
 365 {
 366         if (rc_mode == MODE_OFF) {
 367                 rc_pattern[0] = RC_POWER_OFF_HI;
 368                 rc_pattern[1] = RC_POWER_OFF_LO;
 369                 return;
 370         }
 371
 372         rc_pattern[0] = RC_DEFAULT_HI;
 373         uint t = rc_temp;
 374
 375         if (rc_mode == MODE_COOL) {
 376                 rc_pattern[1] = rc_cool_fan[rc_fan];
 377                 if (t < 17)
 378                         t = 17;
 379                 if (t > 30)
 380                         t = 30;
 381         } else if (rc_mode == MODE_WARM) {
 382                 rc_pattern[1] = RC_WARM;
 383                 if (t < 15)
 384                         t = 15;
 385                 if (t > 25)
 386                         t = 25;
 387         } else {
 388                 rc_pattern[1] = RC_DEHUMIDIFY;
 389                 t = 17;
 390         }
 391
 392         // Encode temperature
 393         rc_pattern[1] |= (t - 15) << 4;
 394
 395         // Compute checksum
 396         uint sum = 0;
 397         for (uint i=0; i<2; i++)
 398                 for (uint j=0; j<32; j+=4)
 399                         sum += (rc_pattern[i] >> j) & 0x0f;
 400         rc_pattern[1] |= (sum & 0x0f) ^ 0x0f;
 401 }
 402
 403 void tim4_isr(void)
 404 {
 405         if (TIM_SR(TIM4) & TIM_SR_UIF) {
 406                 TIM_SR(TIM4) &= ~TIM_SR_UIF;
 407
 408                 bool val;       // 1=pulse, 0=break
 409                 uint duration;  // in μs
 410
 411                 switch (rc_tick) {
 412                         case 0:
 413                                 // Better be safe
 414                                 return;
 415                         case 2:
 416                         case 108:
 417                                 // Initial / final marker
 418                                 val = 0;
 419                                 duration = 3600;
 420                                 // debug_putc('#');
 421                                 break;
 422                         case 110:
 423                                 // Inter-packet gap
 424                                 val = 0;
 425                                 duration = 10000;
 426                                 // debug_putc('$');
 427                                 break;
 428                         case 111:
 429                                 // End of message
 430                                 rc_tick = 0;
 431                                 return;
 432                         default:
 433                                 if (rc_tick % 2) {
 434                                         val = 1;
 435                                         duration = 565;
 436                                         // debug_putc('*');
 437                                 } else {
 438                                         // Even ticks 4 to 106 transmit 52 bits of data
 439                                         uint i = 12 + (rc_tick - 4) / 2;
 440                                         val = 0;
 441                                         if (rc_pattern[i>>5] & (0x80000000 >> (i & 31))) {
 442                                                 duration = 1471;
 443                                                 // debug_putc('B');
 444                                         } else {
 445                                                 duration = 480;
 446                                                 // debug_putc('A');
 447                                         }
 448                                 }
 449                 }
 450
 451                 rc_tick++;
 452
 453                 if (val)
 454                         gpio_set(GPIOA, GPIO8);
 455                 else
 456                         gpio_clear(GPIOA, GPIO8);
 457
 458                 timer_set_period(TIM4, duration - 1);
 459                 timer_generate_event(TIM4, TIM_EGR_UG);
 460                 timer_enable_counter(TIM4);
 461         }
 462 }
 463
 464 static void rc_send(void)
 465 {
 466         if (rc_tick)
 467                 return;
 468
 469         rc_encode();
 470         debug_printf("RC sending: %05x %08x (mode=%d, fan=%d, temp=%d)\n",
 471                 (uint) rc_pattern[0], (uint) rc_pattern[1],
 472                 rc_mode, rc_fan, rc_temp);
 473         rc_tick = 1;
 474
 475         timer_set_period(TIM4, 1);
 476         timer_generate_event(TIM4, TIM_EGR_UG);
 477         timer_enable_counter(TIM4);
 478 }
 479
 480 static bool rc_key(char key)
 481 {
 482         if (key == 'o') {
 483                 rc_mode = MODE_OFF;
 484                 rc_send();
 485                 return true;
 486         } else if (key == 'c') {
 487                 rc_mode = MODE_COOL;
 488                 rc_send();
 489                 return true;
 490         } else if (key == 'w') {
 491                 rc_mode = MODE_WARM;
 492                 rc_send();
 493                 return true;
 494         } else if (key == 'd') {
 495                 rc_mode = MODE_DEHUMIDIFY;
 496                 rc_send();
 497                 return true;
 498         } else if (key == 'a') {
 499                 rc_fan = 0;
 500                 rc_send();
 501                 return true;
 502         } else if (key == 'l') {
 503                 rc_fan = 1;
 504                 rc_send();
 505                 return true;
 506         } else if (key == 'm') {
 507                 rc_fan = 2;
 508                 rc_send();
 509                 return true;
 510         } else if (key == 'h') {
 511                 rc_fan = 3;
 512                 rc_send();
 513                 return true;
 514         } else if (key >= '7' && key <= '9') {
 515                 rc_temp = key - '0' + 10;
 516                 rc_send();
 517                 return true;
 518         } else if (key >= '0' && key <= '6') {
 519                 rc_temp = key - '0' + 20;
 520                 rc_send();
 521                 return true;
 522         } else if (key == '&') {
 523                 rc_temp = 27;
 524                 rc_send();
 525                 return true;
 526         } else if (key == '*') {
 527                 rc_temp = 28;
 528                 rc_send();
 529                 return true;
 530         } else if (key == '(') {
 531                 rc_temp = 29;
 532                 rc_send();
 533                 return true;
 534         } else if (key == ')') {
 535                 rc_temp = 30;
 536                 rc_send();
 537                 return true;
 538         }
 539         return false;
 540 }
 541
 542 /*** USB ***/
 543
 544 static usbd_device *usbd_dev;
 545
 546 enum usb_string {
 547         STR_MANUFACTURER = 1,
 548         STR_PRODUCT,
 549         STR_SERIAL,
 550 };
 551
 552 static char usb_serial_number[13];
 553
 554 static const char *usb_strings[] = {
 555         "United Computer Wizards",
 556         "Sinclair Air Conditioner",
 557         usb_serial_number,
 558 };
 559
 560 static const struct usb_device_descriptor device = {
 561         .bLength = USB_DT_DEVICE_SIZE,
 562         .bDescriptorType = USB_DT_DEVICE,
 563         .bcdUSB = 0x0200,
 564         .bDeviceClass = 0xFF,
 565         .bDeviceSubClass = 0,
 566         .bDeviceProtocol = 0,
 567         .bMaxPacketSize0 = 64,
 568         .idVendor = 0x4242,
 569         .idProduct = 0x0007,
 570         .bcdDevice = 0x0000,
 571         .iManufacturer = STR_MANUFACTURER,
 572         .iProduct = STR_PRODUCT,
 573         .iSerialNumber = STR_SERIAL,
 574         .bNumConfigurations = 1,
 575 };
 576
 577 static const struct usb_endpoint_descriptor endpoints[] = {{
 578         // Bulk end-point for sending values to the display
 579         .bLength = USB_DT_ENDPOINT_SIZE,
 580         .bDescriptorType = USB_DT_ENDPOINT,
 581         .bEndpointAddress = 0x01,
 582         .bmAttributes = USB_ENDPOINT_ATTR_BULK,
 583         .wMaxPacketSize = 64,
 584         .bInterval = 1,
 585 }};
 586
 587 static const struct usb_interface_descriptor iface = {
 588         .bLength = USB_DT_INTERFACE_SIZE,
 589         .bDescriptorType = USB_DT_INTERFACE,
 590         .bInterfaceNumber = 0,
 591         .bAlternateSetting = 0,
 592         .bNumEndpoints = 1,
 593         .bInterfaceClass = 0xFF,
 594         .bInterfaceSubClass = 0,
 595         .bInterfaceProtocol = 0,
 596         .iInterface = 0,
 597         .endpoint = endpoints,
 598 };
 599
 600 static const struct usb_dfu_descriptor dfu_function = {
 601         .bLength = sizeof(struct usb_dfu_descriptor),
 602         .bDescriptorType = DFU_FUNCTIONAL,
 603         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
 604         .wDetachTimeout = 255,
 605         .wTransferSize = 1024,
 606         .bcdDFUVersion = 0x0100,
 607 };
 608
 609 static const struct usb_interface_descriptor dfu_iface = {
 610         .bLength = USB_DT_INTERFACE_SIZE,
 611         .bDescriptorType = USB_DT_INTERFACE,
 612         .bInterfaceNumber = 1,
 613         .bAlternateSetting = 0,
 614         .bNumEndpoints = 0,
 615         .bInterfaceClass = 0xFE,
 616         .bInterfaceSubClass = 1,
 617         .bInterfaceProtocol = 1,
 618         .iInterface = 0,
 619
 620         .extra = &dfu_function,
 621         .extralen = sizeof(dfu_function),
 622 };
 623
 624 static const struct usb_interface ifaces[] = {{
 625         .num_altsetting = 1,
 626         .altsetting = &iface,
 627 }, {
 628         .num_altsetting = 1,
 629         .altsetting = &dfu_iface,
 630 }};
 631
 632 static const struct usb_config_descriptor config = {
 633         .bLength = USB_DT_CONFIGURATION_SIZE,
 634         .bDescriptorType = USB_DT_CONFIGURATION,
 635         .wTotalLength = 0,
 636         .bNumInterfaces = 2,
 637         .bConfigurationValue = 1,
 638         .iConfiguration = 0,
 639         .bmAttributes = 0x80,
 640         .bMaxPower = 50,        // multiplied by 2 mA
 641         .interface = ifaces,
 642 };
 643
 644 static byte usb_configured;
 645 static uint8_t usbd_control_buffer[64];
 646
 647 static void dfu_detach_complete(usbd_device *dev UNUSED, struct usb_setup_data *req UNUSED)
 648 {
 649         // Reset to bootloader, which implements the rest of DFU
 650         debug_printf("Switching to DFU\n");
 651         debug_flush();
 652         scb_reset_core();
 653 }
 654
 655 static enum usbd_request_return_codes dfu_control_cb(usbd_device *dev UNUSED,
 656         struct usb_setup_data *req,
 657         uint8_t **buf UNUSED,
 658         uint16_t *len UNUSED,
 659         void (**complete)(usbd_device *dev, struct usb_setup_data *req))
 660 {
 661         if (req->bmRequestType != 0x21 || req->bRequest != DFU_DETACH)
 662                 return USBD_REQ_NOTSUPP;
 663
 664         *complete = dfu_detach_complete;
 665         return USBD_REQ_HANDLED;
 666 }
 667
 668 static void ep01_cb(usbd_device *dev, uint8_t ep UNUSED)
 669 {
 670         // We received a frame from the USB host
 671         byte buf[8];
 672         uint len = usbd_ep_read_packet(dev, 0x01, buf, 8);
 673         debug_printf("USB: Host sent %u bytes\n", len);
 674 }
 675
 676 static void set_config_cb(usbd_device *dev, uint16_t wValue UNUSED)
 677 {
 678         usbd_register_control_callback(
 679                 dev,
 680                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 681                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 682                 dfu_control_cb);
 683         usbd_ep_setup(dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64, ep01_cb);
 684         usb_configured = 1;
 685 }
 686
 687 static void reset_cb(void)
 688 {
 689         debug_printf("USB: Reset\n");
 690         usb_configured = 0;
 691 }
 692
 693 static volatile bool usb_event_pending;
 694
 695 void usb_lp_can_rx0_isr(void)
 696 {
 697         /*
 698          *  We handle USB in the main loop to avoid race conditions between
 699          *  USB interrupts and other code. However, we need an interrupt to
 700          *  up the main loop from sleep.
 701          *
 702          *  We set up only the low-priority ISR, because high-priority ISR handles
 703          *  only double-buffered bulk transfers and isochronous transfers.
 704          */
 705         nvic_disable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 706         usb_event_pending = 1;
 707 }
 708
 709 static void usb_init(void)
 710 {
 711         // Simulate USB disconnect
 712         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 713         gpio_clear(GPIOA, GPIO11 | GPIO12);
 714         delay_ms(100);
 715
 716         usbd_dev = usbd_init(
 717                 &st_usbfs_v1_usb_driver,
 718                 &device,
 719                 &config,
 720                 usb_strings,
 721                 ARRAY_SIZE(usb_strings),
 722                 usbd_control_buffer,
 723                 sizeof(usbd_control_buffer)
 724         );
 725         usbd_register_reset_callback(usbd_dev, reset_cb);
 726         usbd_register_set_config_callback(usbd_dev, set_config_cb);
 727         usb_event_pending = 1;
 728 }
 729
 730 /*** Main ***/
 731
 732 int main(void)
 733 {
 734         clock_init();
 735         gpio_init();
 736         usart_init();
 737
 738         tick_init();
 739         desig_get_unique_id_as_dfu(usb_serial_number);
 740
 741         debug_printf("Hello, world!\n");
 742
 743         tm_init();
 744         rc_init();
 745         usb_init();
 746
 747         u32 last_blink = 0;
 748
 749         for (;;) {
 750                 if (ms_ticks - last_blink >= 1000) {
 751                         debug_led_toggle();
 752                         last_blink = ms_ticks;
 753                         tm_show();
 754                 }
 755
 756                 if (usart_get_flag(USART1, USART_SR_RXNE)) {
 757                         uint ch = usart_recv(USART1);
 758 #if 0
 759                         if (ch == '1')
 760                                 gpio_set(GPIOA, GPIO8);
 761                         else if (ch == '0')
 762                                 gpio_clear(GPIOA, GPIO8);
 763 #else
 764                         if (rc_key(ch))
 765                                 ;
 766 #endif
 767                         else
 768                                 debug_putc(ch);
 769                 }
 770
 771                 if (usb_event_pending) {
 772                         usbd_poll(usbd_dev);
 773                         usb_event_pending = 0;
 774                         nvic_clear_pending_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 775                         nvic_enable_irq(NVIC_USB_LP_CAN_RX0_IRQ);
 776                 }
 777
 778                 wait_for_interrupt();
 779         }
 780
 781         return 0;
 782 }