Frank - using my K66 PROTO and MSFT wireless I don't see it with the sketch below when PC OFF and powered up on hub (or batterypack)?
Using IDE 1.8.3 and TD_1.38b4 on my windows machine with powered hub ( tried two ) { note both hubs are getting USB power even when hub power is unplugged on this machine with machine off}
This is the USBHost TEST sketch with midi removed - left in other bits as shown - whatever they do. Does it repro your scenario/issue?
T_3.6 starts - turns on LED_BUILTIN:
> No USB in 1st 4 seconds :: waits 4 seconds in setup() before blink
> With USB before 4 secs :: it blinks on the second
> If blinking - a keystroke toggles the LED.
[ tested F_CPU=240/F_BUS=120 ]
Code:
// Simple test of USB Host
// https://forum.pjrc.com/threads/46011-Teensyduino-1-38-Beta-4?p=151921&viewfull=1#post151921
// This example is in the public domain
#include "USBHost_t36.h"
USBHost myusb;
USBHub hub1(myusb);
USBHub hub2(myusb);
USBHub hub3(myusb);
KeyboardController keyboard1(myusb);
KeyboardController keyboard2(myusb);
void setup()
{
pinMode( LED_BUILTIN, OUTPUT );
digitalWriteFast( LED_BUILTIN, 1 );
while (!Serial && millis() < 4000) ; // wait for Arduino Serial Monitor
Serial.println("USB Host Testing");
myusb.begin();
keyboard1.attachPress(OnPress);
keyboard2.attachPress(OnPress);
}
elapsedMillis tBlink;
bool tState = true;
void loop()
{
myusb.Task();
if ( tBlink > 1000) {
tBlink -= 1000;
digitalWriteFast( LED_BUILTIN, tState = !tState );
}
}
void OnPress(int key)
{
digitalWriteFast( LED_BUILTIN, tState = !tState );
Serial.print("key '");
Serial.print((char)key);
Serial.print("' ");
Serial.println(key);
}