Programming Atmega with serial port

Question

Hey people, I need to program the ATmega8 chips via serial. I understand that for doing that I would need to install a bootloader on the chip. And to install a bootloader, I would need a parallel port programmer. Am I right? Or can I just hookup the chip with an MAX232 to make a programmer? I am really confused right now. The best answer here would be a circuit.

UPDATE

He people I just found this http://www.qubbeks.puslapiai.lt/images/articles/AVR_programmer/avr_programatorius_schema.jpg. Do you think this is the kind of circuit which won't require any bootloading?

• Louis Davis: Here is another good source of information about different ways to program AVRs: elm-chan.org/works/avrx/report_e.html

Answer 1

No need for bootloader.

http://forum.cxem.net/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=77070

Then use uniprof program to flash your AVR. I personally used that.

• Rick_2047: Any way I can avoid those diodes and resistors? MAX232 does what this is trying to achieve right? BTW, what are the arrows on the left indicating?
• BarsMonster: Yes, it is possible to do that using max232, but I don't have scheme nearby. This particular scheme does very rough voltage level conversion, max232 is much better.
• Rick_2047: Also, what is uniprof? Couldn't find anything about it. See the schematic I posted in my update. That good enough?
• BarsMonster: getchip.net/wp-content/plugins/download-monitor/…

Answer 2

First, initial programming of AVR chips can not be done with RS232 serial RX/TX. This means that every chip with boot loader in it was either pre-programmed in the factory, or someone else has used some other way of programming to do it (SPI, JTAG, PDI).

My suggestion is to build a cheap 1$ parallel programmer with just few resistors, and then program some boot loader into the chip with RS232 or FTDI driver. That way programmer is not needed any more.

• avra: Sure. Read again OP's message. He understands the chicken and egg problem. If you have empty AVR chip, you need a programmer. Simple RX/TX serial cable is just not enough since it is not supported initially. Once you use some programmer to put bootloader you can use serial, but you can not use serial cable on an empty chip. bit.ly/10qdNzs
• Standard Sandun: so it could be done with serial port, but not with the RT/TX with directly. SI prog works with bitbagging.
• avra: OP wanted to programm AVR similar like it can be done from Arduino IDE - via serial using preprogrammed on board bootloader. He didn't want to use COM port on PC side, some circuit in the middle, and for example SPI on AVR side. He understood well that bootloader is needed for what he wanted, and I explained what is needed to achieve that. Any AVR datasheet holds info on ways available for initial programming, which is also an answer to your question "are you serious?". You are free to interpret OP whatever you like, but it is good that we can all check original message when needed.
• Standard Sandun: The answer to the question "Does this kind of circuit need bootloading?" is YES.At last he realized it. But OP never mentioned about Arduino IDE at all.
• Standard Sandun: But for the question , "Do I need parallel port programer for bootloader uploading?" is NO , that's where I have a clue.