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127 lines
3.3 KiB
C++
127 lines
3.3 KiB
C++
// ArduinoJson - https://arduinojson.org
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// Copyright Benoit Blanchon 2014-2021
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// MIT License
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//
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// This example shows how to parse a JSON document in an HTTP response.
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// It uses the Ethernet library, but can be easily adapted for Wifi.
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//
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// It performs a GET resquest on https://arduinojson.org/example.json
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// Here is the expected response:
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// {
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// "sensor": "gps",
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// "time": 1351824120,
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// "data": [
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// 48.756080,
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// 2.302038
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// ]
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// }
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//
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// https://arduinojson.org/v6/example/http-client/
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#include <ArduinoJson.h>
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#include <Ethernet.h>
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#include <SPI.h>
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void setup() {
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// Initialize Serial port
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Serial.begin(9600);
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while (!Serial) continue;
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// Initialize Ethernet library
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byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
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if (!Ethernet.begin(mac)) {
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Serial.println(F("Failed to configure Ethernet"));
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return;
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}
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delay(1000);
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Serial.println(F("Connecting..."));
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// Connect to HTTP server
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EthernetClient client;
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client.setTimeout(10000);
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if (!client.connect("arduinojson.org", 80)) {
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Serial.println(F("Connection failed"));
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return;
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}
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Serial.println(F("Connected!"));
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// Send HTTP request
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client.println(F("GET /example.json HTTP/1.0"));
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client.println(F("Host: arduinojson.org"));
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client.println(F("Connection: close"));
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if (client.println() == 0) {
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Serial.println(F("Failed to send request"));
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client.stop();
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return;
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}
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// Check HTTP status
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char status[32] = {0};
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client.readBytesUntil('\r', status, sizeof(status));
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// It should be "HTTP/1.0 200 OK" or "HTTP/1.1 200 OK"
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if (strcmp(status + 9, "200 OK") != 0) {
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Serial.print(F("Unexpected response: "));
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Serial.println(status);
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client.stop();
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return;
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}
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// Skip HTTP headers
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char endOfHeaders[] = "\r\n\r\n";
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if (!client.find(endOfHeaders)) {
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Serial.println(F("Invalid response"));
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client.stop();
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return;
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}
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// Allocate the JSON document
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// Use https://arduinojson.org/v6/assistant to compute the capacity.
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const size_t capacity = JSON_OBJECT_SIZE(3) + JSON_ARRAY_SIZE(2) + 60;
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DynamicJsonDocument doc(capacity);
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// Parse JSON object
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DeserializationError error = deserializeJson(doc, client);
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if (error) {
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Serial.print(F("deserializeJson() failed: "));
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Serial.println(error.f_str());
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client.stop();
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return;
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}
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// Extract values
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Serial.println(F("Response:"));
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Serial.println(doc["sensor"].as<const char*>());
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Serial.println(doc["time"].as<long>());
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Serial.println(doc["data"][0].as<float>(), 6);
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Serial.println(doc["data"][1].as<float>(), 6);
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// Disconnect
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client.stop();
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}
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void loop() {
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// not used in this example
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}
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// Performance issue?
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// ------------------
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//
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// EthernetClient is an unbuffered stream, which is not optimal for ArduinoJson.
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// See: https://arduinojson.org/v6/how-to/improve-speed/
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// See also
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// --------
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//
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// https://arduinojson.org/ contains the documentation for all the functions
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// used above. It also includes an FAQ that will help you solve any
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// serialization problem.
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//
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// The book "Mastering ArduinoJson" contains a tutorial on deserialization
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// showing how to parse the response from GitHub's API. In the last chapter,
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// it shows how to parse the huge documents from OpenWeatherMap
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// and Reddit.
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// Learn more at https://arduinojson.org/book/
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// Use the coupon code TWENTY for a 20% discount ❤❤❤❤❤
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