diff --git a/Example_Keyboards/Logitech_K120/Logitech_K120.ino b/Example_Keyboards/Logitech_K120/Logitech_K120.ino
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+++ b/Example_Keyboards/Logitech_K120/Logitech_K120.ino
@@ -0,0 +1,413 @@
+/* Copyright 2021 Frank Adams
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+       http://www.apache.org/licenses/LICENSE-2.0
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+// This software implements a Logitech K120 Keyboard Controller using a Teensy 4.1 wired to the 2 FPC cables, 
+// (there is no circuit board). The standard USB keyboard code would sometimes miss a key press when scanning 
+// at 30 msec. Changing the scan rate to under 1 msec allowed all key presses to be seen but sometimes 
+// two presses would be seen. A debounce/noise filter function called “read_key” has been added to the 
+// code. This function will read a key 5 times in a row with a fixed delay between reads. The function 
+// returns a key-down or key-up result by majority voting.
+//
+// Revision History
+// Initial Release Oct 15, 2021 - Added debounce/noise filter when reading the keyboard
+//
+#define MODIFIERKEY_FN 0x8f   // give Fn key a HID code
+#define CAPS_LED 13 // Teensy LED shows Caps-Lock
+//
+const byte rows_max = 18; // sets the number of rows in the matrix
+const byte cols_max = 8; // sets the number of columns in the matrix
+//
+// Load the normal key matrix with the Teensyduino key names described at www.pjrc.com/teensy/td_keyboard.html
+// A zero indicates no normal key at that location.
+//
+int normal[rows_max][cols_max] = {
+  {0,0,0,0,0,0,0,0},
+  {KEY_C,KEY_X,KEY_DELETE,0,KEY_BACKSLASH,KEYPAD_PERIOD,KEYPAD_9,KEY_SPACE},
+  {KEY_SLASH,KEY_O,KEY_P,KEYPAD_1,KEY_D,KEY_QUOTE,KEY_RIGHT,KEY_PAUSE},
+  {0,0,0,0,0,0,0,0},
+  {KEY_HOME,KEY_Y,KEY_T,KEY_R,KEY_6,KEY_5,KEYPAD_PLUS,KEY_BACKSPACE},
+  {KEY_9,KEY_8,KEY_M,KEY_EQUAL,KEYPAD_3,KEY_COMMA,KEY_7,KEY_V},
+  {KEY_SLASH,KEY_PAGE_DOWN,KEY_ENTER,KEY_NUM_LOCK,KEY_CAPS_LOCK,KEYPAD_0,KEY_END,0x65},
+  {KEY_MINUS,KEY_TAB,KEY_H,KEY_Q,KEY_G,KEY_4,KEY_3,0},
+  {0,0,0,0,0,0,0,0},
+  {KEY_0,KEY_F,KEY_N,KEY_MINUS,KEY_F2,KEY_SEMICOLON,KEYPAD_2,KEY_Z},
+  {0,KEY_F5,KEY_J,KEY_L,KEY_LEFT_BRACE,KEY_K,KEY_PERIOD,KEY_BACKSLASH},
+  {KEY_F7,0,KEY_LEFT,KEY_A,0,KEYPAD_5,KEY_F6,KEYPAD_7},
+  {KEYPAD_4,KEY_I,KEY_E,KEY_F11,KEY_U,KEY_UP,KEY_F12,KEY_INSERT},
+  {0,0,0,0,0,0,0,0},
+  {KEYPAD_ASTERIX,KEY_1,KEY_RIGHT_BRACE,KEY_PAGE_UP,KEY_B,KEY_TILDE,KEY_2,KEY_SCROLL_LOCK},
+  {0,0,KEYPAD_6,KEY_DOWN,KEY_F3,KEY_F4,KEY_S,KEY_PRINTSCREEN},
+  {KEY_F8,KEYPAD_8,KEY_ESC,KEY_F10,KEY_F1,KEY_W,KEY_F9,KEYPAD_ENTER},
+  {0,0,0,0,0,0,0,0}
+};
+// Load the modifier key matrix with key names at the correct row-column location.
+// A zero indicates no modifier key at that location.
+int modifier[rows_max][cols_max] = {
+  {0,0,MODIFIERKEY_RIGHT_SHIFT,0,0,MODIFIERKEY_SHIFT,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,MODIFIERKEY_RIGHT_GUI},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {MODIFIERKEY_GUI,0,0,0,0,0,0,0},   
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},   
+  {0,0,0,MODIFIERKEY_CTRL,0,0,MODIFIERKEY_RIGHT_CTRL,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,MODIFIERKEY_RIGHT_ALT,0,0,MODIFIERKEY_ALT,0,0,0}
+};
+// Load the media key matrix with Fn key names at the correct row-column location.
+// A zero indicates no media key at that location.
+int media[rows_max][cols_max] = {
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},   
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,KEY_SYSTEM_SLEEP,0,0,0,0,0,0},   
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,KEY_SCROLL_LOCK,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0},
+  {0,0,0,0,0,0,0,0}
+};
+// Initialize the old_key matrix with one's.
+// 1 = key not pressed, 0 = key is pressed
+boolean old_key[rows_max][cols_max] = {
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1},
+  {1,1,1,1,1,1,1,1}, 
+  {1,1,1,1,1,1,1,1}
+};
+//
+// Define the Teensy 4.1 I/O numbers (translated from the FPC pin #)
+// Row FPC pin # 02,03,04,05,06,07,08,09,10,11,12,13,14,15,16,17,18
+// Teensy I/O  # 00,22,01,21,02,20,03,19,04,18,05,17,06,29,07,31,08
+//int Row_IO[rows_max] = {0,22,1,21,2,20,3,19,4,18,5,17,6,29,7,31,8}; // Teensy 4.0 I/O numbers for rows
+int Row_IO[rows_max] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 17, 24, 25, 26}; // Teensy 4.0 I/O numbers for rows
+//
+// Column FPC pin # 19,20,21,22,23,24,25,26
+// Teensy I/O     # 33,09,32,10,30,11,28,12
+//int Col_IO[cols_max] = {33,9,32,10,30,11,28,12};  // Teensy 4.1 I/O numbers for columns
+int Col_IO[cols_max] = {27, 28, 29, 30, 31, 32, 14, 15};  // Teensy 4.1 I/O numbers for columns
+
+// Declare variables that will be used by functions
+boolean slots_full = LOW; // Goes high when slots 1 thru 6 contain normal keys
+// slot 1 thru slot 6 hold the normal key values to be sent over USB.
+int slot1 = 0; //value of 0 means the slot is empty and can be used. 
+int slot2 = 0;
+int slot3 = 0;
+int slot4 = 0;
+int slot5 = 0;
+int slot6 = 0;
+//
+int mod_shift_l = 0; // These variables are sent over USB as modifier keys.
+int mod_shift_r = 0; // Each is either set to 0 or MODIFIER_ ...
+int mod_ctrl_l = 0;   
+int mod_ctrl_r = 0;
+int mod_alt_l = 0;
+int mod_alt_r = 0;
+int mod_gui = 0;
+//
+// Function to load the key name into the first available slot
+void load_slot(int key) {
+  if (!slot1)  {
+    slot1 = key;
+  }
+  else if (!slot2) {
+    slot2 = key;
+  }
+  else if (!slot3) {
+    slot3 = key;
+  }
+  else if (!slot4) {
+    slot4 = key;
+  }
+  else if (!slot5) {
+    slot5 = key;
+  }
+  else if (!slot6) {
+    slot6 = key;
+  }
+  if (!slot1 || !slot2 || !slot3 || !slot4 || !slot5 || !slot6)  {
+    slots_full = LOW; // slots are not full
+  }
+  else {
+    slots_full = HIGH; // slots are full
+  }
+}
+//
+// Function to clear the slot that contains the key name
+void clear_slot(int key) {
+  if (slot1 == key) {
+    slot1 = 0;
+  }
+  else if (slot2 == key) {
+    slot2 = 0;
+  }
+  else if (slot3 == key) {
+    slot3 = 0;
+  }
+  else if (slot4 == key) {
+    slot4 = 0;
+  }
+  else if (slot5 == key) {
+    slot5 = 0;
+  }
+  else if (slot6 == key) {
+    slot6 = 0;
+  }
+  if (!slot1 || !slot2 || !slot3 || !slot4 || !slot5 || !slot6)  {
+    slots_full = LOW; // slots are not full
+  }
+  else {
+    slots_full = HIGH; // slots are full
+  }
+}
+//
+// Function to load the modifier key name into the appropriate mod variable
+void load_mod(int m_key) {
+  if (m_key == MODIFIERKEY_LEFT_SHIFT)  {
+    mod_shift_l = m_key;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_SHIFT)  {
+    mod_shift_r = m_key;
+  }
+  else if (m_key == MODIFIERKEY_LEFT_CTRL)  {
+    mod_ctrl_l = m_key;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_CTRL)  {
+    mod_ctrl_r = m_key;
+  }
+  else if (m_key == MODIFIERKEY_LEFT_ALT)  {
+    mod_alt_l = m_key;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_ALT)  {
+    mod_alt_r = m_key;
+  }
+  else if (m_key == MODIFIERKEY_GUI)  {
+    mod_gui = m_key;
+  }
+}
+//
+// Function to load 0 into the appropriate mod variable
+void clear_mod(int m_key) {
+  if (m_key == MODIFIERKEY_LEFT_SHIFT)  {
+    mod_shift_l = 0;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_SHIFT)  {
+    mod_shift_r = 0;
+  }
+  else if (m_key == MODIFIERKEY_LEFT_CTRL)  {
+    mod_ctrl_l = 0;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_CTRL)  {
+    mod_ctrl_r = 0;
+  }
+  else if (m_key == MODIFIERKEY_LEFT_ALT)  {
+    mod_alt_l = 0;
+  }
+  else if (m_key == MODIFIERKEY_RIGHT_ALT)  {
+    mod_alt_r = 0;
+  }
+  else if (m_key == MODIFIERKEY_GUI)  {
+    mod_gui = 0;
+  }
+}
+//
+// Function to send the modifier keys over usb
+void send_mod() {
+  Keyboard.set_modifier(mod_shift_l | mod_shift_r | mod_ctrl_l | mod_ctrl_r | mod_alt_l | mod_alt_r | mod_gui);
+  Keyboard.send_now();
+}
+//
+// Function to send the normal keys in the 6 slots over usb
+void send_normals() {
+  Keyboard.set_key1(slot1);
+  Keyboard.set_key2(slot2);
+  Keyboard.set_key3(slot3);
+  Keyboard.set_key4(slot4);
+  Keyboard.set_key5(slot5);
+  Keyboard.set_key6(slot6);
+  Keyboard.send_now();
+}
+//
+// Function to set a pin to high impedance (acts like open drain output)
+void go_z(int pin)
+{
+  pinMode(pin, INPUT);
+  digitalWrite(pin, HIGH);
+}
+//
+// Function to set a pin as an input with a pullup
+void go_pu(int pin)
+{
+  pinMode(pin, INPUT_PULLUP);
+  digitalWrite(pin, HIGH);
+}
+//
+// Function to send a pin to a logic low
+void go_0(int pin)
+{
+  pinMode(pin, OUTPUT);
+  digitalWrite(pin, LOW);
+}
+//
+// Function to send a pin to a logic high
+void go_1(int pin)
+{
+  pinMode(pin, OUTPUT);
+  digitalWrite(pin, HIGH);
+}
+//
+// Function to read a key multiple times and vote to filter any noise/debounce
+int read_key(int y) {
+  int read1 = digitalRead(Col_IO[y]);
+  delayMicroseconds(2); // increase delay between reads if necessary to filter noise or key bounce
+  int read2 = digitalRead(Col_IO[y]);
+  delayMicroseconds(2);
+  int read3 = digitalRead(Col_IO[y]);
+  delayMicroseconds(2);
+  int read4 = digitalRead(Col_IO[y]);
+  delayMicroseconds(2);
+  int read5 = digitalRead(Col_IO[y]);
+  int readsum = read1 + read2 + read3 + read4 + read5; // count how many 1's were read
+  if (readsum <= 2) { // 0, 1, or 2 means there are more low reads than high reads
+    return 0; // key is pressed
+  }
+  else {
+    return 1; // key is not pressed
+  }
+}
+//
+//----------------------------------Setup-------------------------------------------
+void setup() {
+  for (int a = 0; a < cols_max; a++) {  // loop thru all column pins
+    go_pu(Col_IO[a]); // set each column pin as an input with a pullup
+  }
+//
+  for (int b = 0; b < rows_max; b++) {  // loop thru all row pins
+    go_z(Row_IO[b]); // set each row pin as a floating output
+  } 
+}
+//
+boolean Fn_pressed = HIGH; // Initialize Fn key to HIGH = "not pressed"
+extern volatile uint8_t keyboard_leds; // 8 bits sent from Host to Teensy that give keyboard LED status. Caps lock is bit D1.
+//
+//---------------------------------Main Loop---------------------------------------------
+//
+void loop() {   
+// Scan keyboard matrix with an outer loop that drives each row low and an inner loop that reads every column (with pull ups).
+// The routine looks at each key's present state (by reading the column input pin) and also the previous state from the last scan
+// that was 30msec ago. The status of a key that was just pressed or just released is sent over USB and the state is saved in the old_key matrix.
+// The keyboard keys will read as logic low if they are pressed (negative logic).
+// The old_key matrix also uses negative logic (low=pressed).
+//
+  for (int x = 0; x < rows_max; x++) {   // loop thru the rows
+    go_0(Row_IO[x]); // Activate Row (send it low)
+    delayMicroseconds(15); // give the row time to go low and settle out
+    for (int y = 0; y < cols_max; y++) {   // loop thru the columns
+// **********Modifier keys including the Fn special case
+      if (modifier[x][y] != 0) {  // check if modifier key exists at this location in the array (a non-zero value)
+        if (!read_key(y) && (old_key[x][y])) {  // Read column to see if key is low (pressed) and was previously not pressed
+          if (modifier[x][y] != MODIFIERKEY_FN) {   // Exclude Fn modifier key 
+            load_mod(modifier[x][y]); // function reads which modifier key is pressed and loads it into the appropriate mod_... variable   
+            send_mod(); // function sends the state of all modifier keys over usb including the one that just got pressed
+            old_key[x][y] = LOW; // Save state of key as "pressed"
+          }
+          else {   
+            Fn_pressed = LOW; // Fn status variable is active low
+            old_key[x][y] = LOW; // old_key state is "pressed" (active low)
+          }
+        }
+        else if (read_key(y) && (!old_key[x][y])) {  //check if key is not pressed and was previously pressed
+          if (modifier[x][y] != MODIFIERKEY_FN) { // Exclude Fn modifier key
+            clear_mod(modifier[x][y]); // function reads which modifier key was released and loads 0 into the appropriate mod_... variable
+            send_mod(); // function sends all mod's over usb including the one that just released
+            old_key[x][y] = HIGH; // Save state of key as "not pressed"
+          }
+          else {
+            Fn_pressed = HIGH; // Fn is no longer active
+            old_key[x][y] = HIGH; // old_key state is "not pressed"
+          }
+        }
+      }
+// ***********end of modifier section
+//
+// ***********Normal keys and media keys in this section
+      else if ((normal[x][y] != 0) || (media[x][y] != 0)) {  // check if normal or media key exists at this location in the array
+        if (!read_key(y) && (old_key[x][y]) && (!slots_full)) { // check if key is pressed and was not previously pressed and slots not full
+          old_key[x][y] = LOW; // Save state of key as "pressed"
+          if (Fn_pressed) {  // Fn_pressed is active low so it is not pressed and normal key needs to be sent
+            load_slot(normal[x][y]); //update first available slot with normal key name
+            send_normals(); // send all slots over USB including the key that just got pressed
+          }
+          else if (media[x][y] != 0) { // Fn is pressed so send media if a key exists in the matrix
+            Keyboard.press(media[x][y]); // media key is sent using keyboard press function per PJRC   
+            //delay(5); // delay 5 milliseconds before releasing to make sure it gets sent over USB
+            delayMicroseconds(300);
+            Keyboard.release(media[x][y]); // send media key release
+          }
+        }         
+        else if (read_key(y) && (!old_key[x][y])) { //check if key is not pressed, but was previously pressed
+          old_key[x][y] = HIGH; // Save state of key as "not pressed"
+          if (Fn_pressed) {  // Fn is not pressed
+            clear_slot(normal[x][y]); //clear the slot that contains the normal key name
+            send_normals(); // send all slots over USB including the key that was just released
+          }
+        }
+      }
+// **************end of normal and media key section
+//
+    }
+    go_z(Row_IO[x]); // De-activate Row (send it to hi-z)
+  }
+//
+// **********keyboard scan complete
+//
+// Turn on the LED on the Teensy for Caps Lock based on bit 1 in the keyboard_leds variable controlled by the USB host computer
+//
+  if (keyboard_leds & 1<<1) {  // mask off all bits but D1 and test if set
+    go_1(CAPS_LED); // turn on the LED
+  }
+  else {
+    go_0(CAPS_LED); // turn off the LED
+  }
+//
+  delayMicroseconds(50); // The overall keyboard scanning rate is about 30ms
+}