Add webserver including calibration API endpoint

include/WebServer.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <Adafruit_SCD30.h>
+
+#include <HTTPRequest.hpp>
+#include <HTTPResponse.hpp>
+#include <HTTPServer.hpp>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+class WebServer
+{
+    public:
+        bool start(Adafruit_SCD30 *scd30);
+
+        static WebServer &instance(void)
+        {
+            static WebServer theInstance;
+            return theInstance;
+        }
+
+    private:
+        httpsserver::HTTPServer *m_server;
+
+        Adafruit_SCD30  *m_scd30;
+
+        WebServer(void);
+
+        static void serverTask(void *arg);
+
+        static bool serveFile(String filename, httpsserver::HTTPResponse *res);
+
+        // handlers
+        static void handleRoot(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res);
+        static void handleCalibrate(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res);
+        static void handleStatic(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res);
+};

platformio.ini

@@ -22,6 +22,7 @@ lib_deps =
 	SPI
 	Wire
 	NTPClient
+  esp32_https_server @ 1.0.0
 
 #esp32_https_server
 

src/WebServer.cpp

@@ -0,0 +1,155 @@
+/* HTTP Server setup and handler functions */
+
+#include <LittleFS.h>
+#include <mbedtls/sha256.h>
+
+#include "WebServer.h"
+
+#include "Config.h"
+
+WebServer::WebServer(void)
+{
+    m_server = new httpsserver::HTTPServer();
+}
+
+bool WebServer::serveFile(String filename, httpsserver::HTTPResponse *res)
+{
+    uint8_t buf[1024];
+
+    bool exists = LittleFS.exists(filename);
+
+    if(!exists) {
+        return false;
+    }
+
+    File f = LittleFS.open(filename.c_str(), "r");
+
+    if(!f) {
+        return false;
+    }
+
+    res->setHeader("Content-Length", httpsserver::intToString(f.size()));
+
+    size_t nread = 1;
+    while(nread > 0) {
+        nread = f.readBytes(reinterpret_cast<char*>(buf), 1024);
+
+        if(nread <= 0) {
+            break;
+        }
+
+        res->write(buf, nread);
+    }
+
+    f.close();
+
+    return true;
+}
+
+void WebServer::handleRoot(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res)
+{
+    serveFile("/htdocs/index.html", res);
+    res->setHeader("Content-Type", "text/html");
+}
+
+static void error400(httpsserver::HTTPResponse *res, const std::string &reason)
+{
+    res->println("Error 400: Bad Request");
+    res->println(reason.c_str());
+
+    res->setStatusCode(400);
+}
+
+void WebServer::handleCalibrate(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res)
+{
+    res->setHeader("Content-Type", "text/plain");
+
+    httpsserver::ResourceParameters * params = req->getParams();
+
+    std::string ppmstr;
+    if(!params->getQueryParameter("ppm", ppmstr)) {
+        error400(res, "Parameter 'ppm' not set.");
+        return;
+    }
+
+    int ppmvalue = String(ppmstr.c_str()).toInt();
+    if(ppmvalue < 0 || ppmvalue > 65535) {
+        error400(res, "Parameter 'ppm' out of range [0 .. 65535].");
+        return;
+    }
+
+    res->setStatusCode(200);
+    res->print("Recalibrating SCD30 to ");
+    res->print(ppmvalue);
+    res->println(" ppm");
+
+    WebServer::instance().m_scd30->forceRecalibrationWithReference((uint16_t)ppmvalue);
+}
+
+void WebServer::handleStatic(httpsserver::HTTPRequest *req, httpsserver::HTTPResponse *res)
+{
+    std::string filename = "/htdocs" + req->getRequestString();
+
+    if(*(filename.end()-1) == '/') {
+        // looks like a directory name, so append 'index.html'
+        filename.append("index.html");
+    }
+
+    if(!serveFile(filename.c_str(), res)) {
+        req->discardRequestBody();
+
+        res->setStatusCode(404);
+        res->setHeader("Content-Type", "text/plain");
+
+        res->println("Error 404: Not found");
+    }
+}
+
+void WebServer::serverTask(void *arg)
+{
+    httpsserver::ResourceNode *nodeRoot =
+        new httpsserver::ResourceNode("/", "GET", WebServer::handleRoot);
+    httpsserver::ResourceNode *nodeAPICalibrate =
+        new httpsserver::ResourceNode("/api/calibrate", "GET", WebServer::handleCalibrate);
+
+    // handle all remaining requests by trying to serve static files. If no file is found, 404 is generated.
+    httpsserver::ResourceNode *nodeStatic =
+        new httpsserver::ResourceNode("", "GET", WebServer::handleStatic);
+
+    WebServer &server = WebServer::instance();
+
+    server.m_server->registerNode(nodeRoot);
+    server.m_server->registerNode(nodeAPICalibrate);
+    server.m_server->setDefaultNode(nodeStatic);
+
+    Serial.println("[server] Starting HTTP Server...");
+    server.m_server->start();
+    if (server.m_server->isRunning())
+    {
+        Serial.println("[server] Server ready.");
+
+        while (true)
+        {
+            server.m_server->loop();
+            delay(10);
+        }
+    }
+
+    Serial.println("[server] Server died?! This should never happen.");
+}
+
+bool WebServer::start(Adafruit_SCD30 *scd30)
+{
+    m_scd30 = scd30;
+
+    xTaskCreatePinnedToCore(
+        WebServer::serverTask, /* Task function. */
+        "HTTP Server Task",     /* name of task. */
+        6144,                   /* Stack size of task */
+        NULL,                   /* parameter of the task */
+        1,                      /* priority of the task */
+        NULL,                   /* Task handle to keep track of created task */
+        1);
+
+    return true;
+}

src/main.cpp

@@ -13,6 +13,7 @@
 #include <Fonts/FreeSans12pt7b.h>
 #include <Fonts/FreeSansBold12pt7b.h>
 
+#include "WebServer.h"
 #include "Config.h"
 
 #include <epaper.h>
@@ -215,6 +216,7 @@ void setup(void)
 
 	epaper_draw_and_hibernate(draw_epaper_initial_callback, false);
 
+	WebServer::instance().start(&scd30);
 }
 
 
@@ -341,6 +343,7 @@ void loop(void)
 {
 	static bool first_scd30_readout = true;
 	static uint32_t lastEPaperRefresh = 0;
+	static uint32_t lastUpload = 0;
 	uint32_t now = millis();
 
 	wiFiMulti.run(); // maintain the WiFi connection
@@ -372,18 +375,6 @@ void loop(void)
 		Serial.println(" %");
 		Serial.println("");
 
-		Serial.println("\nUploading...");
-		upload_data();
-
-		if((now - lastEPaperRefresh) >= 60000) {
-			Serial.println("Rendering display...");
-			lastEPaperRefresh = now;
-			epaper_draw_and_hibernate(draw_epaper_callback, false);
-			Serial.println("Display updated.");
-
-			timeseries_prune(&ts_scd30_humidity, 3600); // keep the last hour
-		}
-
 		/*
 		if(!calibrationDone && now >= 300000) {
 			uint16_t calValue = scd30.getForcedCalibrationReference();
@@ -400,5 +391,20 @@ void loop(void)
 		*/
 	}
 
+	if(!first_scd30_readout && (now - lastUpload) >= 30000) {
+		lastUpload = now;
+		Serial.println("\nUploading...");
+		upload_data();
+	}
+
+	if((now - lastEPaperRefresh) >= 60000) {
+		Serial.println("Rendering display...");
+		lastEPaperRefresh = now;
+		epaper_draw_and_hibernate(draw_epaper_callback, false);
+		Serial.println("Display updated.");
+
+		timeseries_prune(&ts_scd30_humidity, 3600); // keep the last hour
+	}
+
 	delay(1000);
 }