#include "wokwi-api.h" #include #include #include #include #define PCA_BASE_ADDR 0x40 #define MODE1 0x00 #define PRE_SCALE 0xFE #define LED0_ON_L 0x06 #define CHANNELS 16 #define REG_COUNT 256 typedef struct { pin_t led[CHANNELS]; pin_t addrPins[6]; pin_t oePin; uint8_t regs[REG_COUNT]; uint8_t ptr; bool ptr_set; uint8_t address; } chip_state_t; static uint8_t get_addr(chip_state_t *chip) { uint8_t a = 0; for (int i = 0; i < 6; i++) { a |= (pin_read(chip->addrPins[i]) ? 1 : 0) << i; } return PCA_BASE_ADDR | a; } static void update_outputs(chip_state_t *chip) { bool oe = pin_read(chip->oePin); for (int ch = 0; ch < CHANNELS; ch++) { int base = LED0_ON_L + 4 * ch; uint16_t on = chip->regs[base] | ((chip->regs[base + 1] & 0x0F) << 8); uint16_t off = chip->regs[base + 2] | ((chip->regs[base + 3] & 0x0F) << 8); bool full_on = chip->regs[base + 1] & 0x10; bool full_off = chip->regs[base + 3] & 0x10; bool level = false; if (oe) { level = false; } else if (full_off) { level = false; } else if (full_on) { level = true; } else { uint16_t duty; if (off >= on) { duty = off - on; } else { duty = 4096 - on + off; } level = duty > 0; } pin_write(chip->led[ch], level); } } static bool on_i2c_connect(void *user_data, uint32_t address, bool read) { chip_state_t *chip = user_data; chip->address = get_addr(chip); if (address != chip->address) { return false; } if (!read) { chip->ptr_set = false; } return true; } static uint8_t on_i2c_read(void *user_data) { chip_state_t *chip = user_data; uint8_t value = chip->regs[chip->ptr]; chip->ptr++; return value; } static bool on_i2c_write(void *user_data, uint8_t data) { chip_state_t *chip = user_data; if (!chip->ptr_set) { chip->ptr = data; chip->ptr_set = true; return true; } chip->regs[chip->ptr] = data; chip->ptr++; update_outputs(chip); return true; } static void on_i2c_disconnect(void *user_data) { (void)user_data; } void chip_init() { chip_state_t *chip = calloc(1, sizeof(chip_state_t)); for (int i = 0; i < 6; i++) { char name[3]; snprintf(name, sizeof(name), "A%d", i); chip->addrPins[i] = pin_init(name, INPUT_PULLDOWN); } chip->oePin = pin_init("OE", INPUT_PULLDOWN); for (int i = 0; i < CHANNELS; i++) { char name[8]; snprintf(name, sizeof(name), "LED%d", i); chip->led[i] = pin_init(name, OUTPUT_LOW); } chip->regs[MODE1] = 0x20; chip->regs[PRE_SCALE] = 121; const i2c_config_t i2c = { .address = 0, .scl = pin_init("SCL", INPUT), .sda = pin_init("SDA", INPUT), .connect = on_i2c_connect, .read = on_i2c_read, .write = on_i2c_write, .disconnect = on_i2c_disconnect, .user_data = chip, }; i2c_init(&i2c); }