Adds rfid example code.

device/main/CMakeLists.txt

@@ -1,2 +1,2 @@
-idf_component_register(SRCS "Networking.cpp" "main.cpp" "WebInterface.cpp"
+idf_component_register(SRCS "Networking.cpp" "main.cpp" "WebInterface.cpp" "RFIDInterface.cpp"
     INCLUDE_DIRS ".")

device/main/RFIDInterface.cpp

@@ -0,0 +1,26 @@
+#include "RFIDInterface.hpp"
+
+#include <esp_log.h>
+
+static const char* TAG = "rfid";
+
+void tag_handler(uint8_t* sn) { // serial number is always 5 bytes long
+    ESP_LOGI(TAG, "Tag: %#x %#x %#x %#x %#x",
+        sn[0], sn[1], sn[2], sn[3], sn[4]
+    );
+}
+
+RFIDInterface::RFIDInterface() {
+	startConfig = (rc522_start_args_t){
+        .miso_io     = 26,
+        .mosi_io     = 25,
+		.sck_io      = 23,
+        .sda_io      = 5,
+        .callback    = &tag_handler
+	};
+}
+
+void RFIDInterface::start() {
+	rc522_start(startConfig);
+}
+

device/main/RFIDInterface.hpp

@@ -0,0 +1,14 @@
+#ifndef _RFID_INTERFACE_HPP
+#define _RFID_INTERFACE_HPP
+
+#include <rc522.h>
+
+class RFIDInterface {
+	rc522_start_args_t startConfig;
+
+	public:
+		RFIDInterface();
+		void start();
+};
+
+#endif

device/main/main.cpp

@@ -4,6 +4,7 @@
 
 #include "Networking.hpp"
 #include "WebInterface.hpp"
+#include "RFIDInterface.hpp"
 
 extern "C" {
     void app_main();
@@ -11,6 +12,7 @@ extern "C" {
 
 Networking networking;
 WebInterface webInterface;
+RFIDInterface rfid;
 
 void app_main(void) {
     initArduino();
@@ -18,6 +20,6 @@ void app_main(void) {
     Serial.begin(115200);
 
     networking.connectWifi();
-
     webInterface.start();
+    rfid.start();
 }