This device is not recognised by widows unless
method1. Keep the BOOT button pressed and then connect to the computer via the data cable. Release the BOOT button after connecting to the computer.
method2. When you press and hold the BOOT key while powering up and then press the Reset key once, you can also enter BootLoader mode.
In a real world application this is not really practical as the buttons are not easily accessable. Why is this happening is the a solution like adding a capacitor to reset or boot if accessible.
After some investigation it appears to be code related to trying to use Serial1.
void setup() {
Serial.begin(115200);
Serial1.begin(115200);
}
This causes windows to not recognise usb port. If the port is connected then it will compile and upload and
Leaving…Hard resetting via RTS pin…
but the port disconnects
Port monitor error: command ‘open’ failed: Invalid serial port. Could not connect to COM9 serial port.
In summary leave out Serial1 and all is fine. Does any one have any thoughts / ideas to solve this