slik-dispenser/arduino/arduino.ino

#include <Arduino_MKRIoTCarrier.h>
#include <WiFiNINA.h>
#include <ArduinoMqttClient.h>
#include "motor.h"
#include "secrets.h"

#define INPUT_SIZE 4

enum state {
	STATE_CONNECTING,
	STATE_LOGGED_OUT,
	STATE_LOGGED_IN,
	STATE_INPUT_PASSCODE,
};

enum state current_state;
char input_code[INPUT_SIZE + 1];
int user_id;

MKRIoTCarrier carrier;
WiFiSSLClient wifi_client;
MqttClient mqtt_client(wifi_client);

// Motor control variables
int motor_count = 0;
int motor_count_max = 64;

uint32_t red_led_color = carrier.leds.Color(255, 0, 0);
uint32_t green_led_color = carrier.leds.Color(0, 255, 0);
uint32_t blue_led_color = carrier.leds.Color(0, 0, 255);

bool is_input_empty()
{
	for (int i = 0; i < INPUT_SIZE; i++) {
		if (input_code[i]) return false;
	}
	return true;
}

bool is_input_full()
{
	for (int i = 0; i < INPUT_SIZE; i++) {
		if (!input_code[i]) return false;
	}
	return true;
}

void change_state(enum state new_state)
{
	// Initialize state
	switch (new_state) {
		case STATE_INPUT_PASSCODE:
			input_code[0] = '\0';
			input_code[1] = '\0';
			input_code[2] = '\0';
			input_code[3] = '\0';
			input_code[4] = '\0';
			break;
	}

	current_state = new_state;
	draw_state();
}

void draw_state()
{
	// Reset
	carrier.display.fillScreen(0x000);
	carrier.leds.fill(0, 0, 5);
	carrier.leds.setBrightness(5);

	switch (current_state) {
		case STATE_CONNECTING:
			carrier.display.setCursor(20, 100);
			carrier.display.setTextSize(3);
			carrier.display.print("Connecting..");
			break;

		case STATE_LOGGED_OUT:
			carrier.display.setCursor(15, 100);
			carrier.display.setTextSize(2);
			carrier.display.print("Press Green Button");
			carrier.leds.fill(green_led_color, 2, 1);
			break;

		case STATE_INPUT_PASSCODE:
			if (is_input_empty()) {
				carrier.display.setCursor(50, 100);
				carrier.display.setTextSize(2);
				carrier.display.print("Please enter");
				carrier.display.setCursor(80, 120);
				carrier.display.print("passcode");
			} else {
				carrier.display.setCursor(50, 100);
				carrier.display.setTextSize(3);
				for (int i = 0; i < INPUT_SIZE; i++) {
					char ch = input_code[i];
					if (!ch) ch = '_';

					carrier.display.print(ch);
					carrier.display.print(' ');
				}
			}

			carrier.leds.fill(blue_led_color, 0, 2);
			carrier.leds.fill(red_led_color, 2, 1);
			carrier.leds.fill(blue_led_color, 3, 2);
			break;

		case STATE_LOGGED_IN:
			carrier.display.setCursor(40, 100);
			carrier.display.setTextSize(3);
			carrier.display.print("Logged in");
			carrier.leds.fill(green_led_color, 2, 1);
			carrier.leds.fill(red_led_color, 4, 1);
			break;
	}

	carrier.leds.show();
}

void setup()
{
	Serial.begin(9600);

	Serial.println("Started");

	carrier.noCase();
	carrier.begin();

	carrier.display.init(240, 240);

	motor_setup();

	pinMode(TFT_BACKLIGHT, OUTPUT);
	digitalWrite(TFT_BACKLIGHT, HIGH);

	change_state(STATE_CONNECTING);

	Serial.println("Connecting to WiFi...");

	if (wifi_enterprise) WiFi.beginEnterprise(wifi_ssid, wifi_username, wifi_password);
	else WiFi.begin(wifi_ssid, wifi_password);

	while (WiFi.status() != WL_CONNECTED) delay(1000);

	Serial.println("Connected to WiFi, connecting to MQTT...");

	mqtt_client.setUsernamePassword(mqtt_username, mqtt_password);
	if (!mqtt_client.connect(mqtt_server, 8883)) {
		Serial.print("MQTT connection failed with error code: ");
		Serial.println(mqtt_client.connectError());
		return;
	}

	Serial.println("Connected to MQTT");

	carrier.Buzzer.beep();

	mqtt_client.subscribe("dispense");
	mqtt_client.subscribe("login");

	change_state(STATE_LOGGED_OUT);
}

void loop()
{
	carrier.Buttons.update();

	// Rotate motor if needed
	if (motor_count) {
		motor_clockwise();
		motor_count--;
	}

	// Receive MQTT messages
	int message_size = mqtt_client.parseMessage();
	if (message_size) {
		String topic = mqtt_client.messageTopic();
		Serial.print("Got message with topic: ");
		Serial.println(topic);

		// Parse message
		char *message = (char *)malloc(message_size + 1);
		for (int i = 0; i < message_size && mqtt_client.available(); i++) {
			message[i] = (char)mqtt_client.read();
		}
		message[message_size] = '\0';

		Serial.print("and payload: ");
		Serial.println(message);

		// Check topic
		if (topic == "dispense") {
			Serial.println("Dispensing...");

			// Start rotating motor
			motor_count += motor_count_max;
		} else if (topic == "login") {
			Serial.println("Logged in");

			if (sscanf(message, "%d", &user_id) > 0) {
				change_state(STATE_LOGGED_IN);
			} else {
				change_state(STATE_INPUT_PASSCODE);
			}
		}

		free(message);
	}

	touchButtons buttons[] = { TOUCH0, TOUCH1, TOUCH3, TOUCH4 };
	char input_characters[] = "1234";

	switch (current_state) {
		case STATE_LOGGED_OUT:
			if (carrier.Buttons.onTouchDown(TOUCH2)) {
				change_state(STATE_INPUT_PASSCODE);
			}
			break;
		case STATE_INPUT_PASSCODE:
			if (carrier.Buttons.onTouchDown(TOUCH2)) {
				if (is_input_empty()) {
					change_state(STATE_LOGGED_OUT);
				} else {
					for (int i = INPUT_SIZE - 1; i >= 0; i--) {
						if (input_code[i]) {
							input_code[i] = '\0';
							draw_state();
							break;
						}
					}
				}
			}

			for (int i = 0; i < sizeof(buttons) / sizeof(buttons[0]); i++) {
				if (carrier.Buttons.onTouchDown(buttons[i])) {
					for (int j = 0; j < INPUT_SIZE; j++) {
						if (!input_code[j]) {
							input_code[j] = input_characters[i];
							break;
						}
					}

					if (is_input_full()) {
						mqtt_client.beginMessage("login_request");
						mqtt_client.print(input_code);
						mqtt_client.endMessage();
					}

					draw_state();

					break;
				}
			}

			break;
		case STATE_LOGGED_IN:
			if (carrier.Buttons.onTouchDown(TOUCH2)) {
				char *user_id_str = (char *)malloc(4);
				snprintf(user_id_str, 4, "%d", user_id);

				mqtt_client.beginMessage("dispense_request");
				mqtt_client.print(user_id_str);
				mqtt_client.endMessage();

				free(user_id_str);
			}

			if (carrier.Buttons.onTouchDown(TOUCH4)) {
				change_state(STATE_LOGGED_OUT);
			}
			break;
	}

	delay(2);
}