I'm developing a board for use with the Raspberry Pi. It has an atmega 328 installed with the Arduino boot loader already loaded. I want to test the arduino side before I install anything else.
I have no usb access on the dev board. Only rs232 (ttl levels). I think it should be possible to load a sketch on to another Arduino and use that to mimic a "programmer". Plug that in to the computer and use it to program the "dev" 328 via the serial pins and the standard boot loader.
Sounds odd I know, but this is just a hack to get me going while I wait for more parts.
I have found loads of info on writing a new boot loader with a second Arduino, but nothing on this.
If you could offer me any pointers on this it would be much appreciated. If what I have said makes no sense let me know and I'll try to explain it a bit better.
Another way is to put a row of 6 male headers on the board to allow programming direct from the Arduino IDE via an FTDI breakout or cable.
The Programming a Sketch section on Nick Gammon's guide How to make an Arduino-compatible minimal board is the reference I typically run to for this. Any standalone project I make now includes a permanently mounted set of headers, and the cap to make this possible.
It does mean an FTDI cable or breakout is needed, but that's a small additional cost for the convenience imo.
I do intend to pick up an FTDI break out board and cable but at the moment I don't have one, and with Christmas on the door step it will be a little while before I can get my hands on one. I was hoping to get a hack going until I can get the rest of the hardware for the project and do it properly. I am also going to be running the chip at 3.3v so would like to test this side of things as well, but would be happy to run at 5V for now and just get it flashing the obligatory led
Did you include a 6-pin ICSP header on your atmega328p design? If so, forget about using the bootloader and program the mcu via ICSP instead, using your Arduino as the programmer.
