Tasmota/lib/ArduinoJson-5.11.2/examples/JsonHttpClient/JsonHttpClient.ino

185 lines
4.9 KiB
Arduino
Raw Normal View History

// Sample Arduino Json Web Client
// Downloads and parse http://jsonplaceholder.typicode.com/users/1
//
// Copyright Benoit Blanchon 2014-2017
// MIT License
//
// Arduino JSON library
// https://bblanchon.github.io/ArduinoJson/
// If you like this project, please add a star!
#include <ArduinoJson.h>
#include <Ethernet.h>
#include <SPI.h>
EthernetClient client;
const char* server = "jsonplaceholder.typicode.com"; // server's address
const char* resource = "/users/1"; // http resource
const unsigned long BAUD_RATE = 9600; // serial connection speed
const unsigned long HTTP_TIMEOUT = 10000; // max respone time from server
const size_t MAX_CONTENT_SIZE = 512; // max size of the HTTP response
// The type of data that we want to extract from the page
struct UserData {
char name[32];
char company[32];
};
// ARDUINO entry point #1: runs once when you press reset or power the board
void setup() {
initSerial();
initEthernet();
}
// ARDUINO entry point #2: runs over and over again forever
void loop() {
if (connect(server)) {
if (sendRequest(server, resource) && skipResponseHeaders()) {
UserData userData;
if (readReponseContent(&userData)) {
printUserData(&userData);
}
}
}
disconnect();
wait();
}
// Initialize Serial port
void initSerial() {
Serial.begin(BAUD_RATE);
while (!Serial) {
; // wait for serial port to initialize
}
Serial.println("Serial ready");
}
// Initialize Ethernet library
void initEthernet() {
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
if (!Ethernet.begin(mac)) {
Serial.println("Failed to configure Ethernet");
return;
}
Serial.println("Ethernet ready");
delay(1000);
}
// Open connection to the HTTP server
bool connect(const char* hostName) {
Serial.print("Connect to ");
Serial.println(hostName);
bool ok = client.connect(hostName, 80);
Serial.println(ok ? "Connected" : "Connection Failed!");
return ok;
}
// Send the HTTP GET request to the server
bool sendRequest(const char* host, const char* resource) {
Serial.print("GET ");
Serial.println(resource);
client.print("GET ");
client.print(resource);
client.println(" HTTP/1.0");
client.print("Host: ");
client.println(host);
client.println("Connection: close");
client.println();
return true;
}
// Skip HTTP headers so that we are at the beginning of the response's body
bool skipResponseHeaders() {
// HTTP headers end with an empty line
char endOfHeaders[] = "\r\n\r\n";
client.setTimeout(HTTP_TIMEOUT);
bool ok = client.find(endOfHeaders);
if (!ok) {
Serial.println("No response or invalid response!");
}
return ok;
}
// Parse the JSON from the input string and extract the interesting values
// Here is the JSON we need to parse
// {
// "id": 1,
// "name": "Leanne Graham",
// "username": "Bret",
// "email": "Sincere@april.biz",
// "address": {
// "street": "Kulas Light",
// "suite": "Apt. 556",
// "city": "Gwenborough",
// "zipcode": "92998-3874",
// "geo": {
// "lat": "-37.3159",
// "lng": "81.1496"
// }
// },
// "phone": "1-770-736-8031 x56442",
// "website": "hildegard.org",
// "company": {
// "name": "Romaguera-Crona",
// "catchPhrase": "Multi-layered client-server neural-net",
// "bs": "harness real-time e-markets"
// }
// }
bool readReponseContent(struct UserData* userData) {
// Compute optimal size of the JSON buffer according to what we need to parse.
// See https://bblanchon.github.io/ArduinoJson/assistant/
const size_t BUFFER_SIZE =
JSON_OBJECT_SIZE(8) // the root object has 8 elements
+ JSON_OBJECT_SIZE(5) // the "address" object has 5 elements
+ JSON_OBJECT_SIZE(2) // the "geo" object has 2 elements
+ JSON_OBJECT_SIZE(3) // the "company" object has 3 elements
+ MAX_CONTENT_SIZE; // additional space for strings
// Allocate a temporary memory pool
DynamicJsonBuffer jsonBuffer(BUFFER_SIZE);
JsonObject& root = jsonBuffer.parseObject(client);
if (!root.success()) {
Serial.println("JSON parsing failed!");
return false;
}
// Here were copy the strings we're interested in
strcpy(userData->name, root["name"]);
strcpy(userData->company, root["company"]["name"]);
// It's not mandatory to make a copy, you could just use the pointers
// Since, they are pointing inside the "content" buffer, so you need to make
// sure it's still in memory when you read the string
return true;
}
// Print the data extracted from the JSON
void printUserData(const struct UserData* userData) {
Serial.print("Name = ");
Serial.println(userData->name);
Serial.print("Company = ");
Serial.println(userData->company);
}
// Close the connection with the HTTP server
void disconnect() {
Serial.println("Disconnect");
client.stop();
}
// Pause for a 1 minute
void wait() {
Serial.println("Wait 60 seconds");
delay(60000);
}