I am not sure if this question has been asked before but here's what I wanted to do.
I have a Arduino Nano, which I need to update with a new sketch. The plan is to be able to use another Arduino (maybe a Nano again), with an SD card reader and a sketch loaded as HEX file on it. Then connect both using a 4 pin RX/TX/5V/GND and upload the sketch from the transmitter to the receiver. Is it possible?
I am not sure how to do this; I know I can use one Arduino as an ISP to update other, but I am thinking of streaming the hex file to the other. Has anyone done this, any hints would be extremely helpful.