jurs:
It should be no problem to upload 250K sketches from the Arduino IDE to the MEGA2560 by using the USB cable.But to do so, the MEGA2560 needs to have the MEGA2560 bootloader installed.
If you destroyed the bootloader on your MEGA and now want it back, you can do either way:
- use an ISP to install the bootloader on your board
- use an Arduino "UNO as ISP" to install the bootloader on your board
Ater the bootloader is back on the board, you can use the USB cable for uploading sketches.
That is good news! So I need to purchase either an "UNO" or a dedicated programmer to install a new bootloader. It seems I might as well buy a new UNO, which is less expensive than a programmer.
Does it seem that when I replaced the bootloader on my MEGA 2560 with my USBTinyISP and IDE, that either the bootloader was put at the wrong address or perhaps the wrong bootloader was installed? I ask because my MEGA 2560 works fine except for its apparent memory limitation.
Thank you for your expertise and time.
Frank