A-Star Micro Arduino Serial takes half-second to initialize?

Hi! Not a complaint, just curious.

Using Arduino 1.6.9 Serial.print in a loop, it takes over 500-1500 msec for Serial to be “ready”, and text to appear on the serial monitor.

Is that the Arduino code? or the 32U4? or the USB controller on the A-Star?

Other AVRs and ESP-12s print immediately. No biggy, just curious.


Hello, Doug.

The bootloader on our A-Star 32U4 boards waits 750ms for inputs from the RST line to put it in bootloader mode before running the uploaded program. You can read more about the difference between our bootloader and the Caterina bootloader used on the Arduino Leonardo, Arduino Micro and several other ATmega32U4 boards in the “The A-Star 32U4 Bootloader” section of the A-Star 32U4 user’s guide.