I am thinking about using a Arduino mini pro in a project. I would like to upload a AVR hex file unto the Arduino's ATmega 328P and use the as I would in a nerd kit. I don't want to make use of any Arduino libraries or features. I only require access to the CPU and the pin connections on the Arduino board. I am looking for a good way to program and run the CPU on the Arduino as if it was on a nerdkit board.

I have a couple of USBASP programmers around. I also have some FT232RL FT232 USB to Serial adapter module USB TO 232 For Arduino pro mini.

Does anyone know if it is possible to upload a C code derived hex file to this Arduino using the Arduino boatloader that comes on the CPU by using the USB serial adapter? Could I connect the USBASP programmer to the appropriate pins on the Arduino board and upload a hex file to the CPU just as if it where on a nerdkit board?

I used a USBASP programmer. I have the CPU on the Arduino programmed now.

Short answer YES!! I believe the crystal is different on a Arduino than a NerdKit but it is just a Atmel 328P you do not have to use a bootloader.

BTW, you don't have to program an arduino with an ISP programmer if you don't want to use the processing development platform. I programmed them with standard C most of the time. All you have to have is a USB/Serial adapter that has DTR connections, and change your makefile to support the arduino bootloader (basically have to change avr109 to arduino and maybe the baud) Its been a while...

When I found a compiled .hex file for arduino I am using following steps to get the hex file into the ATMega328P:

1) Connect the USBasp programmer to myMultiProg Board

2) Place the ATMega328 in the myMultiProg Board

3) Run Burnomat Software to burn the hex file on the ATMega328P.

Thanks lnino

actually I was trying to burn the ATMega328P that comes mounted on a arduino mini pro board with a .hex file. I compiled the .hex file from code I wrote in C code using programmers notepad.

I ended up just skipping the arduino bootloader by using a USBASP programmer and Khazama AVR Programmer software, it has work fine.