Added basic speed limiter

src/main.cpp

@@ -5,6 +5,9 @@
 // For reading FIFO
 #include <fcntl.h>
 #include <unistd.h>
+// For sleep
+#include <chrono>
+#include <thread>
 
 // Local files
 #include "utility/bitmap.hpp"
@@ -78,28 +81,41 @@ int main(int argc, char *argv[]) {
 	Dox.connect_loop();
 
 
+	// Frame rate limiter
+	std::chrono::time_point<
+		std::chrono::steady_clock,
+		std::chrono::nanoseconds
+	> t = std::chrono::steady_clock::now();
+	//t += std::chrono::milliseconds(30);
+	//this_thread::sleep_until(t);
+
+
 	while (1) {
 
 		if (Dox.is_connected()) {
-			if (Dox.get_animation_mode() == 0x02) {
-				buf.update();
-				fft.update(buf);
+			if (std::chrono::steady_clock::now() > t + std::chrono::milliseconds(30)) {
+				if (Dox.get_animation_mode() == 0x02) {
+					buf.update();
+					fft.update(buf);
 
-				hid_buf[0] = CMD_ANIM_DATA_fft;
-				for (size_t i = 0; i < 10; i++) {
-					// Get height from fft, apply bottom_skip
-					ssize_t h = fft.get_output()[i] - BOTTOM_SKIP;
+					hid_buf[0] = CMD_ANIM_DATA_fft;
+					for (size_t i = 0; i < 10; i++) {
+						// Get height from fft, apply bottom_skip
+						ssize_t h = fft.get_output()[i] - BOTTOM_SKIP;
 
-					// Enforce max and min
-					// max implicitly enforces top_skip
-					h = h>KB_RESOLUTION ? KB_RESOLUTION : h;
-					h = h<0 ? 0 : h;
+						// Enforce max and min
+						// max implicitly enforces top_skip
+						h = h>KB_RESOLUTION ? KB_RESOLUTION : h;
+						h = h<0 ? 0 : h;
 
-					hid_buf[i + 1] = h;
+						hid_buf[i + 1] = h;
+					}
 				}
-			}
 
-			Dox.write(CMD_ANIM_DATA, hid_buf, Dox.packet_size);
+				Dox.write(CMD_ANIM_DATA, hid_buf, Dox.packet_size);
+
+				t = std::chrono::steady_clock::now();
+			}
 
 			// Dox.write might detect that we've been disconnected,
 			// and Dox.read will fail if we are.