writing speed is detected, and the model mayhem sets backlight according to

speed

firmware/modelsuntype5.c

@@ -93,6 +93,10 @@ void printMatrix(void) {
     sendString("\n");
 }
 
+void setSpeed(uint8_t speed) {
+    // not used in this model/version
+}
+
 void setLeds(uint8_t LEDstate) {
     if (LEDstate & LED_NUM) { // light up num lock
         PORTLEDS &= ~(1 << LEDNUM);