I was contemplating on the difference between the original ATmega2560 board (shown in blue in the diagram) and the main controller board that comes part of APM-1 (which is in red). I see this this APM-1 red board DOES NOT have a USB cable attached, whilst the blue one has a USB serial socket.
Original Arduino ATMega2560:
My APM-1 controller board: (This one is different)
The pins are also different in both. Can someone show me why is it so, and the difference.
Thank you very much.
Did you find the answer?
Both you the same chip ATMega2560. The difference b/w them is that APM is made specifically to interface it with ArduIMU (IMU board) and additional functions like telemetry. It is basically another product using the same AVR chip.
The Arduino ATMega250 is a kit for using it to work with the chip (supposedly lesser functionalities than APM board.
This is what I could see from my working with the APM board. Any comments are welcome.