// Wokwi Custom Chip - For information and examples see: // https://link.wokwi.com/custom-chips-alpha // // SPDX-License-Identifier: MIT // Copyright (C) 2022 Uri Shaked / wokwi.com #include "wokwi-api.h" #include #include const int ADDRESS = 0x20; typedef struct { pin_t PIN_SDA; pin_t PIN_SCL; pin_t PIN_INT; pin_t PIN_A0; pin_t PIN_A1; pin_t PIN_A2; pin_t PIN_P0; pin_t PIN_P1; pin_t PIN_P2; pin_t PIN_P3; pin_t PIN_P4; pin_t PIN_P5; pin_t PIN_P6; pin_t PIN_P7; uint8_t counter; } chip_state_t; static bool on_i2c_connect(void *user_data, uint32_t address, bool connect); static uint8_t on_i2c_read(void *user_data); static bool on_i2c_write(void *user_data, uint8_t data); static void on_i2c_disconnect(void *user_data); void chip_init() { chip_state_t *chip = malloc(sizeof(chip_state_t)); chip->PIN_INT = pin_init("INT", INPUT); chip->PIN_A0 = pin_init("A0", INPUT); chip->PIN_A1 = pin_init("A1", INPUT); chip->PIN_A2 = pin_init("A2", INPUT); chip->PIN_P0 = pin_init("P0", OUTPUT); chip->PIN_P1 = pin_init("P1", OUTPUT); chip->PIN_P2 = pin_init("P2", OUTPUT); chip->PIN_P3 = pin_init("P3", OUTPUT); chip->PIN_P4 = pin_init("P4", OUTPUT); chip->PIN_P5 = pin_init("P5", OUTPUT); chip->PIN_P6 = pin_init("P6", OUTPUT); chip->PIN_P7 = pin_init("P7", OUTPUT); chip->counter = 0; const i2c_config_t i2c_config = { .user_data = chip, .address = ADDRESS, .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, // Optional }; i2c_init(&i2c_config); // The following message will appear in the browser's DevTools console: printf("Hello from custom chip!\n"); } static void update_pins(chip_state_t *chip) { for (uint8_t i = 0; i < 8; i++) { switch (i) { case 0: pin_write(chip->PIN_P0, chip->counter & (1 << i) ? HIGH : LOW); break; case 1: pin_write(chip->PIN_P1, chip->counter & (1 << i) ? HIGH : LOW); break; case 2: pin_write(chip->PIN_P2, chip->counter & (1 << i) ? HIGH : LOW); break; case 3: pin_write(chip->PIN_P3, chip->counter & (1 << i) ? HIGH : LOW); break; case 4: pin_write(chip->PIN_P4, chip->counter & (1 << i) ? HIGH : LOW); break; case 5: pin_write(chip->PIN_P5, chip->counter & (1 << i) ? HIGH : LOW); break; case 6: pin_write(chip->PIN_P6, chip->counter & (1 << i) ? HIGH : LOW); break; case 7: pin_write(chip->PIN_P7, chip->counter & (1 << i) ? HIGH : LOW); break; } } } bool on_i2c_connect(void *user_data, uint32_t address, bool connect) { return true; /* Ack */ } uint8_t on_i2c_read(void *user_data) { chip_state_t *chip = user_data; chip->counter = 0; chip->counter |= pin_read(chip->PIN_P7); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P6); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P5); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P4); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P3); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P2); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P1); chip->counter<<=1; chip->counter |= pin_read(chip->PIN_P0); return chip->counter; } bool on_i2c_write(void *user_data, uint8_t data) { chip_state_t *chip = user_data; chip->counter = data; update_pins(chip); return true; // Ack } void on_i2c_disconnect(void *user_data) { // Do nothing }