Connecting Teensy 3.1 to computer requires a button press?

[Key_Clacker]

I'm interested in leaving my teensy in an enclosure, but it seems that everytime I plug in the teensy, I've got to press the reboot button in order to get my program to load. Is this a common problem, or is my particular application to blame?

I currently have a USB host shield attached to it (with extra capacitance across the 5V rail), and an i2c character LCD running at 5v.

Thanks for any tips...

 

[pictographer]

Usually when you apply power, whatever program was previously loaded just starts running. You shouldn't need to press the button. Maybe the host shield code changes this?

 

[stevech]

If the program previously stored in Flash was faulty in certain ways, a button push is needed to force a bootload of some stable code.

 

[Key_Clacker]

Thanks, I'll try adding a delay because I do notice that there is a bit of code where it checks if USB has been established:

if (Usb.Init() == -1)
Serial.println("OSC did not start.");