#include <SPI.h>
#include <Ethernet.h>
void setup() {
Ethernet.init(15); // IOXESP32 Ethernet shield
Serial.begin(115200);
}
void loop() {
auto link = Ethernet.linkStatus();
Serial.print("Link status: ");
switch (link) {
case Unknown:
Serial.println("Unknown");
break;
case LinkON:
Serial.println("ON");
break;
case LinkOFF:
Serial.println("OFF");
break;
}
delay(1000);
}
เลือกบอร์ด เลือกพอร์ต แล้วอัพโหลดโปรแกรมลงบอร์ด
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 shield
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
unsigned int localPort = 8888; // local port to listen for UDP packets
const char timeServer[] = "time.nist.gov"; // time.nist.gov NTP server
const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message
byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets
// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
void setup() {
Ethernet.init(15); // IOXESP32 Ethernet shield
// Open serial communications and wait for port to open:
Serial.begin(115200);
// start Ethernet and UDP
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// Check for Ethernet hardware present
if (Ethernet.hardwareStatus() == EthernetNoHardware) {
Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :(");
} else if (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);
}
void loop() {
sendNTPpacket(timeServer); // send an NTP packet to a time server
// wait to see if a reply is available
delay(1000);
if (Udp.parsePacket()) {
// We've received a packet, read the data from it
Udp.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:
unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
unsigned long 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):
unsigned long 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:
const unsigned long seventyYears = 2208988800UL;
// subtract seventy years:
unsigned long 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 again
delay(10000);
Ethernet.maintain();
}
// send an NTP request to the time server at the given address
void sendNTPpacket(const char * address) {
// set all bytes in the buffer to 0
memset(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, Mode
packetBuffer[1] = 0; // Stratum, or type of clock
packetBuffer[2] = 6; // Polling Interval
packetBuffer[3] = 0xEC; // Peer Clock Precision
// 8 bytes of zero for Root Delay & Root Dispersion
packetBuffer[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 123
Udp.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 shield
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
char serverAddress[] = "www.google.com"; // server address
int port = 80;
EthernetClient ethClient;
HttpClient client = HttpClient(ethClient, serverAddress, port);
void setup() {
Ethernet.init(15); // IOXESP32 Ethernet shield
Serial.begin(115200);
// start Ethernet and UDP
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// Check for Ethernet hardware present
if (Ethernet.hardwareStatus() == EthernetNoHardware) {
Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :(");
} else if (Ethernet.linkStatus() == LinkOFF) {
Serial.println("Ethernet cable is not connected.");
}
// no point in carrying on, so do nothing forevermore:
while (true) {
delay(1);
}
}
}
void loop() {
Serial.println("making GET request");
client.get("/");
// read the status code and body of the response
int 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 shield
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
char serverAddress[] = "api.chnwt.dev"; // server address
int port = 443;
EthernetClient basic_client;
ESP_SSLClient ssl_client;
HttpClient client = HttpClient(ssl_client, serverAddress, port);
void setup() {
Ethernet.init(15); // IOXESP32 Ethernet shield
Serial.begin(115200);
// start Ethernet and UDP
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// Check for Ethernet hardware present
if (Ethernet.hardwareStatus() == EthernetNoHardware) {
Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :(");
} else if (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 verification
ssl_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);
}
void loop() {
Serial.println("making GET request");
client.get("/thai-gold-api/latest");
// read the status code and body of the response
int 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)
