add midi example and i2c test

libs/calliope-midi/midi.ts

@@ -0,0 +1,23 @@
+serial.redirect(
+    SerialPin.P0,
+    SerialPin.P1,
+    31250
+);
+
+basic.forever(() => {
+    for (let note = 0; note <= 90 - 1; note++) {
+        // Note on channel 1 (0x90), some note value (note),
+        // middle velocity (0x45):
+        serial.writeString(String.fromCharCode(144));
+        serial.writeString(String.fromCharCode(note));
+        serial.writeString(String.fromCharCode(69));
+        basic.pause(100);
+        // Note on channel 1 (0x90), some note value (note),
+        // silent velocity (0x00):
+        serial.writeString(String.fromCharCode(144));
+        serial.writeString(String.fromCharCode(note));
+        serial.writeString("\0");
+        basic.pause(100);
+        basic.pause(1000);
+    }
+});

libs/calliope-midi/pxt.json

@@ -0,0 +1,11 @@
+{
+    "name": "midi",
+    "description": "MIDI Example via Serial",
+    "files": [
+        "midi.ts"
+    ],
+    "public": true,
+    "dependencies": {
+        "core": "file:../core"
+    }
+}