Refact json response and fixed piezo tone

test/serial/piezo.ts

@@ -0,0 +1,24 @@
+import { Board, Piezo } from "johnny-five";
+
+const board = new Board({
+    port: '/dev/ttyUSB0',
+    repl: false
+});
+
+board.on('ready', () => {
+    const piezo = new Piezo(11);
+    
+    let ins = 0;
+    
+    board.loop(500, async () => {
+        piezo.play({
+            song: "C4",
+            beats: 1/2,
+            tempo: 100
+        })
+        await new Promise(resolve => setTimeout(resolve, 100));
+        piezo.note("C4", 100);
+        await new Promise(resolve => setTimeout(resolve, 100));
+        piezo.tone(262 * 7.3, 100);
+    })
+})