Author Topic: Axon bootloader vs. programmer.. Whats the difference?  (Read 1245 times)

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Offline tranzparencyTopic starter

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Axon bootloader vs. programmer.. Whats the difference?
« on: December 10, 2010, 06:32:56 AM »
Still a bit hazy on the difference between the 2.  One is hardware, the other software?

The Axon has a programmer built in so this is what is confusing me.  Since I don't need to purchase a "programmer" (supposedly), I looked through the axon Makefile and saw it was using avrisp (through avrdude).  So I setup a makefile in X-Code (since I'm a mac guy) that ran through avr-gcc and avr-objcopy.  Zero problems.

Using Crosspack on OSX, I assumed that if the Axon used avrisp through avrdude on windows.. And Crosspack suported avrisp, then it should recognize that the programer exists.  "Device not found".

So using Crosspack with the Axon on OS X.  Which "-c programID" should I use since avrisp doesn't work? Yet it does through avrdude on windows. 

Thanks for you time.  Love even a hint of insight not only the difference between programmers and bootloaders, but avrdude in general.  Is one (windows) official, and the Crosspack implementation different and non supported?  Objecive doesn't even have a forum for it.


Offline garrettg84

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Re: Axon bootloader vs. programmer.. Whats the difference?
« Reply #1 on: December 10, 2010, 09:16:34 AM »
Some dev/robot boards do not come with usb-serial/ttl converters (to save on cost). For boards built like this, a programmer is required.

I build most of my own boards now and for me, a programmer is necessary. Even if I build a board with a usb-serial/ttl converter, I still require a programmer to load the boot loader.

Programmers are also useful for setting the fuses on AVR chips.

All AVR chips that include hardware usb functionality come with usb bootloaders from the factory now.

I'm not sure how to answer the questions about Crosspack. I run OS X too, but always use AVR Studio in a VM. Good luck.

Offline Admin

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Re: Axon bootloader vs. programmer.. Whats the difference?
« Reply #2 on: December 10, 2010, 11:51:01 AM »
I wouldn't be able to help you with OS X, as I'm an XP guy . . .

A hardware programmer is an external device that writes to the memory of the ATmega chip. It's an absolute must when writing to a blank chip. These devices have many features, such as writing to fuses, and are really fast, but a quality one costs between $20 and $40.

A bootloader is software that was already uploaded by a hardware programmer. The software lets a program be read in by UART (ie USB), and will place it into the program space. This way you no longer need a hardware programmer to upload future programs. It has some limits however, including slower programming speeds and not being able to change fuse settings.

The Axon has a bootloader pre-installed so you do not need to purchase a hardware programmer. You can still use one, if you want. Personally, I prefer hardware programmers.


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