Demo of boot protocol working

This adds serial debugging output showing when a boot protocol HID report is sent (and
when an NKRO protocol report is sent, too), and the contents of that report. It also
changes the variable used to decide which type of report to send to the host, without
changing the `getDescriptor()` and `setup()` methods, which still do whatever they do with
the `protocol` variable, and `UEDATX`.

I don't understand why this works, but it seems to allow proper switching between boot
protocol and report protocol on macOS & Linux (the two machines I have access to).

src/BootKeyboard/BootKeyboard.cpp

@@ -196,15 +196,29 @@ uint8_t BootKeyboard_::getLeds(void) {
 }
 
 uint8_t BootKeyboard_::getProtocol(void) {
-  return protocol;
+  if (boot_protocol_) {
+    return HID_BOOT_PROTOCOL;
+  } else {
+    return HID_REPORT_PROTOCOL;
+  }
 }
 
 void BootKeyboard_::setProtocol(uint8_t protocol) {
-  this->protocol = protocol;
+  if (protocol == HID_BOOT_PROTOCOL) {
+    boot_protocol_ = true;
+  } else {
+    boot_protocol_ = false;
+  }
 }
 
 int BootKeyboard_::sendReport(void) {
   if (memcmp(&_lastKeyReport, &_keyReport, sizeof(_keyReport))) {
+    Serial.print(F("sending boot report: "));
+    for (byte i{0}; i < 8; ++i) {
+      Serial.print(F(" "));
+      Serial.print(int(_keyReport.bytes[i]));
+    }
+    Serial.println();
     // if the two reports are different, send a report
     int returnCode = USB_Send(pluggedEndpoint | TRANSFER_RELEASE, &_keyReport, sizeof(_keyReport));
     memcpy(&_lastKeyReport, &_keyReport, sizeof(_keyReport));

src/BootKeyboard/BootKeyboard.h

@@ -78,6 +78,7 @@ class BootKeyboard_ : public PluggableUSBModule {
 
   uint8_t epType[1];
   uint8_t protocol;
+  bool boot_protocol_{false};
   uint8_t idle;
 
   uint8_t leds;

src/MultiReport/Keyboard.cpp

@@ -98,6 +98,12 @@ void Keyboard_::end(void) {
 }
 
 int Keyboard_::sendReportUnchecked(void) {
+  Serial.print(F("sending nkro report:"));
+  for (byte i{0}; i < 29; ++i) {
+    Serial.print(F(" "));
+    Serial.print(int(keyReport.allkeys[i]));
+  }
+  Serial.println();
     return HID().SendReport(HID_REPORTID_NKRO_KEYBOARD, &keyReport, sizeof(keyReport));
 }