EasyBulider 滑桿Slider 數值0-180 透過MQTT 控制 WOKWI 伺服馬達
WOKWI程式
#include <ESP32Servo.h>
#include <HX711.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <WiFi.h>
#include <PubSubClient.h>
Adafruit_SSD1306 display(128, 64, &Wire, -1);
HX711 scale;
WiFiClient espClient;
PubSubClient client(espClient);
Servo myservo;
uint8_t angle = 0;
uint16_t weight = 0;
uint16_t weight1 = 0;
String message = "";
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "mqtt-dashboard.com";
char data1;
int j = 0;
char data2[4];
void setup_wifi() {
delay(10);
Serial.println();
Serial.print(F("Connecting to "));
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(F("."));
}
// randomSeed(micros());
Serial.println(F("WiFi connected"));
Serial.println(F("IP address: "));
Serial.println(WiFi.localIP());
}
void reconnect() {
while (!client.connected()) {
Serial.print(F("Attempting MQTT connection..."));
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
if (client.connect(clientId.c_str())) {
Serial.println(F("connected"));
client.subscribe("ebpro_wokwi/servo");
} else {
Serial.print(F("failed, rc="));
Serial.print(client.state());
Serial.println(F(" try again in 5 seconds"));
delay(5000);
}
}
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print(F("Message arrived ["));
Serial.print(topic);
Serial.print(F("] "));
for (int i = 0; i < length; i++) {
data1 = ((char)payload[i]);
if (data1 >= '0' && data1 <= '9') {
data2[j] = data1;
j++;
}
}
angle = atoi(data2);
j = 0;
memset(data2, 0, sizeof(data2));
myservo.write(angle);
Serial.println(angle);
tampil();
}
void setup() {
Serial.begin(115200);
myservo.attach(5);
scale.begin(19, 18);//DT,SCK
if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for (;;);
}
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
weight = round(scale.get_units() * 50 / 21); //gram
message = "{\"gram\":" + String(weight) + "}";
if (weight != weight1) {
Serial.print(F("Publish message: "));
Serial.println(message);
client.publish("wokwi_ebpro/weight", message.c_str());
tampil();
}
weight1 = weight;
}
void tampil() {
display.clearDisplay();
display.setTextSize(2);
display.setTextColor(WHITE);
display.setCursor(0, 0);
display.print("angle:");
display.print(angle);
display.print(char(247));
display.setCursor(0, 25);
display.print("Weight:");
display.setCursor(50, 45);
display.print(weight / 1000.0, 1);
display.print("kg");
display.display();
}
