เมื่ออัพโหลดโปรแกรมลงบอร์ดแล้ว ให้เปิด Serial Monitor ขึ้นมา ปรับเป็น 115200 แล้วกดปุ่ม Reset บนบอร์ด IOXESP32 1 ครั้ง หากสายแลนมีการเชื่อมต่ออยู่ และขอ IP จาก DHCP ได้ จะมีข้อความ ON ขึ้น (ดังรูป)
ทดสอบถอดสายแลนออก ผลที่ได้จะขึ้น OFF (ดังรูป)
การดึงค่าเวลาจากอินเตอร์เน็ต (NTP)
ใช้โค้ดโปรแกรมต่อไปนี้ในการทดสอบ
#include<SPI.h>#include<Ethernet.h>#include<EthernetUdp.h>// Enter a MAC address for your controller below.// Newer Ethernet shields have a MAC address printed on a sticker on the shieldbyte mac[] = {0xDE,0xAD,0xBE,0xEF,0xFE,0xED};unsignedint localPort =8888; // local port to listen for UDP packetsconstchar timeServer[] ="time.nist.gov"; // time.nist.gov NTP serverconstint NTP_PACKET_SIZE =48; // NTP time stamp is in the first 48 bytes of the messagebyte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets// A UDP instance to let us send and receive packets over UDPEthernetUDP Udp;voidsetup() {Ethernet.init(15); // IOXESP32 Ethernet shield // Open serial communications and wait for port to open:Serial.begin(115200); // start Ethernet and UDPif (Ethernet.begin(mac) ==0) {Serial.println("Failed to configure Ethernet using DHCP"); // Check for Ethernet hardware presentif (Ethernet.hardwareStatus() == EthernetNoHardware) {Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :("); } elseif (Ethernet.linkStatus() == LinkOFF) {Serial.println("Ethernet cable is not connected."); } // no point in carrying on, so do nothing forevermore:while (true) {delay(1); } }Udp.begin(localPort);}voidloop() {sendNTPpacket(timeServer); // send an NTP packet to a time server // wait to see if a reply is availabledelay(1000);if (Udp.parsePacket()) { // We've received a packet, read the data from itUdp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer // the timestamp starts at byte 40 of the received packet and is four bytes, // or two words, long. First, extract the two words:unsignedlong highWord =word(packetBuffer[40],packetBuffer[41]);unsignedlong lowWord =word(packetBuffer[42],packetBuffer[43]); // combine the four bytes (two words) into a long integer // this is NTP time (seconds since Jan 1 1900):unsignedlong secsSince1900 = highWord <<16| lowWord;Serial.print("Seconds since Jan 1 1900 = ");Serial.println(secsSince1900); // now convert NTP time into everyday time:Serial.print("Unix time = "); // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:constunsignedlong seventyYears =2208988800UL; // subtract seventy years:unsignedlong epoch = secsSince1900 - seventyYears; // print Unix time:Serial.println(epoch); // print the hour, minute and second:Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT)Serial.print((epoch %86400L) /3600); // print the hour (86400 equals secs per day)Serial.print(':');if (((epoch %3600) /60) <10) { // In the first 10 minutes of each hour, we'll want a leading '0'Serial.print('0'); }Serial.print((epoch %3600) /60); // print the minute (3600 equals secs per minute)Serial.print(':');if ((epoch %60) <10) { // In the first 10 seconds of each minute, we'll want a leading '0'Serial.print('0'); }Serial.println(epoch %60); // print the second } // wait ten seconds before asking for the time againdelay(10000);Ethernet.maintain();}// send an NTP request to the time server at the given addressvoidsendNTPpacket(constchar* address) { // set all bytes in the buffer to 0memset(packetBuffer,0, NTP_PACKET_SIZE); // Initialize values needed to form NTP request // (see URL above for details on the packets)packetBuffer[0] =0b11100011; // LI, Version, ModepacketBuffer[1] =0; // Stratum, or type of clockpacketBuffer[2] =6; // Polling IntervalpacketBuffer[3] =0xEC; // Peer Clock Precision // 8 bytes of zero for Root Delay & Root DispersionpacketBuffer[12] =49;packetBuffer[13] =0x4E;packetBuffer[14] =49;packetBuffer[15] =52; // all NTP fields have been given values, now // you can send a packet requesting a timestamp:Udp.beginPacket(address,123); // NTP requests are to port 123Udp.write(packetBuffer, NTP_PACKET_SIZE);Udp.endPacket();}
อัพโหลดโปรแกรมลงบอร์ด แล้วเปิด Serial Monitor ขึ้นมา ผลที่ได้ค่าเวลา UTC จะขึ้นมาแล้ว
#include<ArduinoHttpClient.h>#include<SPI.h>#include<Ethernet.h>// Enter a MAC address for your controller below.// Newer Ethernet shields have a MAC address printed on a sticker on the shieldbyte mac[] = {0xDE,0xAD,0xBE,0xEF,0xFE,0xED};char serverAddress[] ="www.google.com"; // server addressint port =80;EthernetClient ethClient;HttpClient client =HttpClient(ethClient, serverAddress, port);voidsetup() {Ethernet.init(15); // IOXESP32 Ethernet shieldSerial.begin(115200); // start Ethernet and UDPif (Ethernet.begin(mac) ==0) {Serial.println("Failed to configure Ethernet using DHCP"); // Check for Ethernet hardware presentif (Ethernet.hardwareStatus() == EthernetNoHardware) {Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :("); } elseif (Ethernet.linkStatus() == LinkOFF) {Serial.println("Ethernet cable is not connected."); } // no point in carrying on, so do nothing forevermore:while (true) {delay(1); } }}voidloop() {Serial.println("making GET request");client.get("/"); // read the status code and body of the responseint statusCode =client.responseStatusCode(); String response =client.responseBody();Serial.print("Status code: ");Serial.println(statusCode);Serial.print("Response: ");Serial.println(response);Serial.println("Wait five seconds");delay(5000);}
ผลที่ได้ ข้อมูลจาก google.com แสดงขึ้นมาบน Serial Monitor แล้ว
#include<ArduinoHttpClient.h>#include<SPI.h>#include<Ethernet.h>#include<ESP_SSLClient.h>// Enter a MAC address for your controller below.// Newer Ethernet shields have a MAC address printed on a sticker on the shieldbyte mac[] = {0xDE,0xAD,0xBE,0xEF,0xFE,0xED};char serverAddress[] ="api.chnwt.dev"; // server addressint port =443;EthernetClient basic_client;ESP_SSLClient ssl_client;HttpClient client =HttpClient(ssl_client, serverAddress, port);voidsetup() {Ethernet.init(15); // IOXESP32 Ethernet shieldSerial.begin(115200); // start Ethernet and UDPif (Ethernet.begin(mac) ==0) {Serial.println("Failed to configure Ethernet using DHCP"); // Check for Ethernet hardware presentif (Ethernet.hardwareStatus() == EthernetNoHardware) {Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :("); } elseif (Ethernet.linkStatus() == LinkOFF) {Serial.println("Ethernet cable is not connected."); } // no point in carrying on, so do nothing forevermore:while (true) {delay(1); } } // ignore server ssl certificate verificationssl_client.setInsecure(); // Set the receive and transmit buffers size in bytes for memory allocation (512 to 16384).ssl_client.setBufferSizes(1024 /* rx */,512 /* tx */); // Assign the basic client // Due to the basic_client pointer is assigned, to avoid dangling pointer, basic_client should be existed // as long as it was used by ssl_client for transportation.ssl_client.setClient(&basic_client);}voidloop() {Serial.println("making GET request");client.get("/thai-gold-api/latest"); // read the status code and body of the responseint statusCode =client.responseStatusCode(); String response =client.responseBody();Serial.print("Status code: ");Serial.println(statusCode);Serial.print("Response: ");Serial.println(response);Serial.println("Wait five seconds");delay(5000);}
ผลที่ได้ ราคาทองคำวันนี้ที่ดึงมาจาก API จะแสดงขึ้นมาบน Serial Monitor แล้ว
การรับ-ส่งข้อมูลผ่าน MQTT
MQTT คืออะไร? (ตอบโดย ChatGPT)
MQTT (Message Queuing Telemetry Transport) คือโปรโตคอลการสื่อสารที่มีน้ำหนักเบาและมีประสิทธิภาพสูง ออกแบบมาเพื่อการส่งข้อมูลระหว่างอุปกรณ์ที่มีการเชื่อมต่อผ่านเครือข่ายที่มีความเสถียรต่ำหรือแบนด์วิดท์จำกัด MQTT ถูกพัฒนาโดย IBM และปัจจุบันเป็นมาตรฐานเปิดที่ได้รับการดูแลโดย OASIS (Organization for the Advancement of Structured Information Standards)
#include<SPI.h>#include<Ethernet.h>#include<PubSubClient.h>// Update these with values suitable for your network.byte mac[] = { 0xDE,0xED,0xBA,0xFE,0xFE,0xED };constchar* server ="broker.emqx.io";voidcallback(char* topic,byte* payload,unsignedint length) {Serial.print("Message arrived [");Serial.print(topic);Serial.print("] ");for (int i=0;i<length;i++) {Serial.print((char)payload[i]); }Serial.println();}EthernetClient ethClient;PubSubClientclient(ethClient);voidreconnect() { // Loop until we're reconnectedwhile (!client.connected()) {Serial.print("Attempting MQTT connection..."); // Attempt to connectif (client.connect("MyIOXESP32")) {Serial.println("connected"); // Once connected, publish an announcement...client.publish("/IOXESP32-Ethernet-Test","hello world"); // ... and resubscribeclient.subscribe("/IOXESP32-Ethernet-Test"); } else {Serial.print("failed, rc=");Serial.print(client.state());Serial.println(" try again in 5 seconds"); // Wait 5 seconds before retryingdelay(5000); } }}voidsetup(){Ethernet.init(15); // IOXESP32 Ethernet shieldSerial.begin(115200);client.setServer(server,1883);client.setCallback(callback); // start Ethernet and UDPif (Ethernet.begin(mac) ==0) {Serial.println("Failed to configure Ethernet using DHCP"); // Check for Ethernet hardware presentif (Ethernet.hardwareStatus() == EthernetNoHardware) {Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :("); } elseif (Ethernet.linkStatus() == LinkOFF) {Serial.println("Ethernet cable is not connected."); } // no point in carrying on, so do nothing forevermore:while (true) {delay(1); } }}voidloop(){if (!client.connected()) {reconnect(); }client.loop();}
