I've been having this problem on a sketch I'm working on but to remove all extraneous information I can recreate the problem with blink.
Today I did some testing where I compiled using different options using Arduino 1.8.19 and Teensy 1.56. The hardware has the trace cut between VUSB and VIN. I feed power to each via a diode.
It failed unless I dropped the clock speed down to 48 MHz and then only when compiled with Faster or Fastest option. Fast worked but only when I had Serial+MIDI but not when No USB was selected. How can I diagnose why this Fails (or Works)? I don't like leaving this process to chance depending on clock speed, code length or how it was linked together. I need the teensy to work reliably on both battery (with step up regulator) or USB.
Code:
/*-+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain.
*/
// Pin 13 has an LED connected on most Arduino boards.
// Pin 11 has the LED on Teensy 2.0
// Pin 6 has the LED on Teensy++ 2.0
// Pin 13 has the LED on Teensy 3.0
// give it a name:
int led = 13;
// the setup routine runs once when you press reset:
void setup() {
// initialize the digital pin as an output.
pinMode(led, OUTPUT);
}
// the loop routine runs over and over again forever:
void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(led, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second
}
Today I did some testing where I compiled using different options using Arduino 1.8.19 and Teensy 1.56. The hardware has the trace cut between VUSB and VIN. I feed power to each via a diode.
It failed unless I dropped the clock speed down to 48 MHz and then only when compiled with Faster or Fastest option. Fast worked but only when I had Serial+MIDI but not when No USB was selected. How can I diagnose why this Fails (or Works)? I don't like leaving this process to chance depending on clock speed, code length or how it was linked together. I need the teensy to work reliably on both battery (with step up regulator) or USB.