怎么用5v的arduino控制12v的共阴rgb灯带，用9014三极管

Posted 2023-05-13

怎么用5v的arduino控制12v的共阴rgb灯带，用9014三极管大概如图，补全基极

因为LED有固定压降，你这种接法，在a点处的电压是固定4.3V，所以导致，每个LED上的分压根本不够，导致要不不亮，要不就是很微弱的亮。

建议把所有LED的阴极接到三极管的集电极，阳极接12V电源，取消电阻R，然后通过调整三极管基极处的电阻大小，来调节三极管Ic的电流就可以了，因为只要电流恒定在LED的工作电流上就可以正常工作，至于多出去的电压在哪，在三极管ce结上。

追问

灯改不了，是灯带，如果用pnp三极管或者mos可以吗？

追答

PNP可以，用P-mos也可以，不可以用NPN和N-mos

追问

能不能帮忙画个图

追答

借LED的三极管，基极需要串入一个电阻

电阻的大小你应该会算吧

追问

谢谢

追答

上面的电路有一个缺点，我把它修改以后的电路发给你

出现一种特殊情况会无法关断

这个图就不会出现无法关断的情况。

参考技术A 每个基极串电阻，电阻阻值Rb＝Vcc－Ube/（lc/β）

Arduino ESP32 Web网页控制RGB灯

Arduino ESP32 Web网页控制RGB灯

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ESP32 LED PWM控制器具有16个独立通道，可配置为生成具有不同属性的PWM信号。 我们可以使用ESP32的LED PWM控制器和零知开发工具对LED进行调光。

• 连线：
  1、红色引脚连接到ESP32的GPIO25
  2、绿色引脚连接到ESP32的GPIO26
  3、蓝色引脚连接到ESP32的GPIO27

实例代码

	#include <WiFi.h>
	// 填写wifi信息
	const char* ssid     = "";
	const char* password = "";
	// Set web server port number to 80
	WiFiServer server(80);
	// Decode HTTP GET value
	String redString = "0";
	String greenString = "0";
	String blueString = "0";
	int pos1 = 0;
	int pos2 = 0;
	int pos3 = 0;
	int pos4 = 0;
	// Variable to store the HTTP req  uest
	String header;
	// Red, green, and blue pins for PWM control
	const int redPin = 25;     // 13 corresponds to GPIO13
	const int greenPin = 26;   // 12 corresponds to GPIO12
	const int bluePin = 27;    // 14 corresponds to GPIO14
	// Setting PWM frequency, channels and bit resolution
	const int freq = 5000;
	const int redChannel = 0;
	const int greenChannel = 1;
	const int blueChannel = 2;
	// Bit resolution 2^8 = 256
	const int resolution = 8;
	// Current time
	unsigned long currentTime = millis();
	// Previous time
	unsigned long previousTime = 0;
	// Define timeout time in milliseconds (example: 2000ms = 2s)
	const long timeoutTime = 2000;
	void setup() {
	    Serial.begin(115200);
	    // configure LED PWM functionalitites
	    ledcSetup(redChannel, freq, resolution);
	    ledcSetup(greenChannel, freq, resolution);
	    ledcSetup(blueChannel, freq, resolution);
	    // attach the channel to the GPIO to be controlled
	    ledcAttachPin(redPin, redChannel);
	    ledcAttachPin(greenPin, greenChannel);
	    ledcAttachPin(bluePin, blueChannel);
	    // Connect to Wi-Fi network with SSID and password
	    Serial.println();
	    Serial.print("Connecting to ");
	    Serial.println(ssid);
	    WiFi.begin(ssid, password);
	    while (WiFi.status() != WL_CONNECTED) {
	        delay(500);
	        Serial.print(".");
	    }
	    // Print local IP address and start web server
	    Serial.println("");
	    Serial.println("WiFi connected.");
	    Serial.println("IP address: ");
	    Serial.println(WiFi.localIP());
	    server.begin();
	}
	void loop() {
	    WiFiClient client = server.available();   // Listen for incoming clients
	    if (client) {                             // If a new client connects,
	        currentTime = millis();
	        previousTime = currentTime;
	        Serial.println("New Client.");          // print a message out in the serial port
	        String currentLine = "";                // make a String to hold incoming data from the client
	        while (client.connected() && currentTime - previousTime <= timeoutTime) {            // loop while the client's connected
	            currentTime = millis();
	            if (client.available()) {             // if there's bytes to read from the client,
	                char c = client.read();             // read a byte, then
	                Serial.write(c);                    // print it out the serial monitor
	                header += c;
	                if (c == '\\n') {                    // if the byte is a newline character
	                    // if the current line is blank, you got two newline characters in a row.
	                    // that's the end of the client HTTP request, so send a response:
	                    if (currentLine.length() == 0) {
	                        // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
	                        // and a content-type so the client knows what's coming, then a blank line:
	                        client.println("HTTP/1.1 200 OK");
	                        client.println("Content-type:text/html");
	                        client.println("Connection: close");
	                        client.println();
	                        // Display the HTML web page
	                        client.println("<!DOCTYPE html><html>");
	                        client.println("<head><meta name=\\"viewport\\" content=\\"width=device-width, initial-scale=1\\">");
	                        client.println("<link rel=\\"icon\\" href=\\"data:,\\">");
	                        client.println("<link rel=\\"stylesheet\\" href=\\"https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css\\">");
	                        client.println("<script src=\\"https://cdnjs.cloudflare.com/ajax/libs/jscolor/2.0.4/jscolor.min.js\\"></script>");
	                        client.println("</head><body><div class=\\"container\\"><div class=\\"row\\"><h1>ESP Color Picker</h1></div>");
	                        client.println("<a class=\\"btn btn-primary btn-lg\\" href=\\"#\\" id=\\"change_color\\" role=\\"button\\">Change Color</a> ");
	                        client.println("<input class=\\"jscolor {onFineChange:'update(this)'}\\" id=\\"rgb\\"></div>");
	                        client.println("<script>function update(picker) {document.getElementById('rgb').innerHTML = Math.round(picker.rgb[0]) + ', ' +  Math.round(picker.rgb[1]) + ', ' + Math.round(picker.rgb[2]);");
	                        client.println("document.getElementById(\\"change_color\\").href=\\"?r\\" + Math.round(picker.rgb[0]) + \\"g\\" +  Math.round(picker.rgb[1]) + \\"b\\" + Math.round(picker.rgb[2]) + \\"&\\";}</script></body></html>");
	                        // The HTTP response ends with another blank line
	                        client.println();
	                        // Request sample: /?r201g32b255&
	                        // Red = 201 | Green = 32 | Blue = 255
	                        if (header.indexOf("GET /?r") >= 0) {
	                            pos1 = header.indexOf('r');
	                            pos2 = header.indexOf('g');
	                            pos3 = header.indexOf('b');
	                            pos4 = header.indexOf('&');
	                            redString = header.substring(pos1 + 1, pos2);
	                            greenString = header.substring(pos2 + 1, pos3);
	                            blueString = header.substring(pos3 + 1, pos4);
	                            /*Serial.println(redString.toInt());
	                            Serial.println(greenString.toInt());
	                            Serial.println(blueString.toInt());*/
	                            ledcWrite(redChannel, abs(255 - redString.toInt()));
	                            ledcWrite(greenChannel, abs(255 - greenString.toInt()));
	                            ledcWrite(blueChannel, abs(255 - blueString.toInt()));
	                        }
	                        // Break out of the while loop
	                        break;
	                    } else { // if you got a newline, then clear currentLine
	                        currentLine = "";
	                    }
	                } else if (c != '\\r') {  // if you got anything else but a carriage return character,
	                    currentLine += c;      // add it to the end of the currentLine
	                }
	            }
	        }
	        // Clear the header variable
	        header = "";
	        // Close the connection
	        client.stop();
	        Serial.println("Client disconnected.");
	        Serial.println("");
	    }
	}