Hi there,
I have started from scratch and built an Arduino on a breadboard as per - https://www.arduino.cc/en/Main/Standalone
I have successfully boot-loaded an ATMEGA328P - PU chip. I did this using the offline IDE v1.8.13. For some reason my Mac, which runs OS Catalina 10.15.6, does not recognise either the Breakout board USB nor the USBtinyISP USB connections. Despite this, by choosing not to select a Port, I am still able to successfully boatload (screenshot attached - so by not choosing either the bluetooth option or cu.URT0 I am still able to upload).
The issue then happens when I try to upload a sketch e.g blink_led. When I try offline, I get the message ''Serial Port Not Selected'' with only the previously mention ports to choose from. Both do not work. (Attachment 2)
I then tried uploading using the online IDE with the Arduino Create plugin, it fails to recognise the board and I get an ''Error Uploading, check if the selected board is currently unavailable''. (Attachment 3)
Please could you advise me on what I need to do?
Best,
Timi