Removing the Arduino Bootloader

Hello All

I've been trying to figure this out for a couple of days now, and I think it's mostly because I don't really know what to look for.

I want to remove the Arduino bootloader on my mega board so that I can write standard AVR C code and upload it through the USB connection.

Is it possible to do this without buying a programmer? I read somewhere that I can use another Arduino as a programmer (have a spare Uno lying around), but how do I go about doing the whole thing?

The Arduino language & IDE has a bunch of annoying bugs and I'd like to just code it in plain old C. I have some experience with PIC mcus, but they're just rubbish :d

Thanks in advance

The Arduino language is C++.

If you eliminate the bootloader, then you have to use a programmer. You can use another Arduino for that.

sTrider_7:
I read somewhere that I can use another Arduino as a programmer (have a spare Uno lying around), but how do I go about doing the whole thing?

If you are going to use a programmer regularly, just buy a USBasp off ebay for $5 or so. The "Uno as a programmer" is a good party trick, but a bit Rube Goldberg-ish for regular use. The USBasp will also have useful features like a slow clock generator.

sTrider_7:
The Arduino language & IDE has a bunch of annoying bugs and I'd like to just code it in plain old C. I have some experience with PIC mcus, but they're just rubbish :d

Lots of people program Arduinos without using the Arduino IDE. I myself use Emacs + makefiles, others use things like Eclipse + one of the plugins for Arduino. There are also several projects current where people are having their own crack at writing a better IDE. The thing is, it's the gnu compiler + avrdude sitting under the IDE that's really doing all the work -- the IDE just provides a simple editor and a certain amount of preprocessing of your "sketch" code into something that (hopefully) will be acceptable to the gcc compiler. What the IDE preprocessor really does isn't really that much (and it doesn't do it very well anyway, IMHO), so it's no great loss to work without it. Many (like me) see it a definite advantage, in fact.

I see, thanks for the advice.

If I were to erase the Arduino bootloader, is there a way to do it without purchasing another programmer?

I'll definitely get a programmer in the near future, it's just a question of finding a decent one since availability is very limited in my country.

You don't need to remove the bootloader in order to upload Arduino-less code.

tim7:
You don't need to remove the bootloader in order to upload Arduino-less code.

Wait what?

sTrider_7:
I'll definitely get a programmer in the near future, it's just a question of finding a decent one since availability is very limited in my country.

I got mine on eBay.

sTrider_7:
I want to remove the Arduino bootloader on my mega board so that I can write standard AVR C code and upload it through the USB connection.

Arduino IDE puts the compiled hex file in a directory like this:
C:\Users\Victor\AppData\Local\Temp\build1325897986179133197.tmp\Blink.cpp.hex

You have to remove that "Blink.cpp.hex" from there and replace it with the code compiled by you using another IDE, ex. Avr Studio, and then load the program into your Arduino Mega using Arduino IDE.

sTrider_7:

tim7:
You don't need to remove the bootloader in order to upload Arduino-less code.

Wait what?

The bootloader is just a piece of software that is loaded in the AVR that allows
a tool (avrdude in this case) to upload code to the AVR. The bootloader itself
is totally independent of anything Arduino.

As shipped the AVR fuses are set to create two sections in the FLASH. Bootloader and application.
The "Arduino" bootloader is small piece of code in the AVR that uses the serial port to update the flash
with the user application (code/program/sketch).
The bootloader runs at reset/powerup if there is no attempt to upload anything, the bootloader
will start the application code.
The application code can be written using any toolset you prefer. The Arduino tools are just one option.

avrdude is a tool that is used upload code into the flash.
avrdude can be used with an ISP programmer to upload code to the flash
avrdude can also use other mechanisms like a serial port that talks to a serial based programmer or to a bootloader.
The Arduino IDE uses avrdude to talk over a serial port to a pre-installed bootloader in the AVR chip.
The newer IDE can also use an ISP progammer to upload code. When an ISP programmer is used,
a bootloader is not used so the flash space used by the bootloader code frees up and can be used
by the application code.

If you don't want to use a bootloader, you will need some sort of ISP programmer.
Like Pico, I recommend getting a USBasp programmer off ebay.
I like the USBasp kk multicopter programmers (about $5-$10 USD) because they come with a 6 pin ISP
cable instead of 10 pin so no adapter is needed.

--- bill

sTrider_7:
If I were to erase the Arduino bootloader, is there a way to do it without purchasing another programmer?

I'll definitely get a programmer in the near future, it's just a question of finding a decent one since availability is very limited in my country.

You need a programmer if you aren't going to use the bootloader. You can use an Arduino as a programmer as I describe here:

Also the "Arduino as ISP" method lets you upload from the IDE using another Arduino.

I'd like to just code it in plain old C ...

As I said in my earlier response you can code in "plain old C" if you want to. Make a tab in the IDE called xxxx.c and put your code into it.

pico:
The "Uno as a programmer" is a good party trick, but a bit Rube Goldberg-ish for regular use.

Works well for me. Despite owning a Pololu AVR Programmer (which is a very nice programmer; currently only $10!) I've only used an Uno or Teensy for the last several months.

The USBasp will also have useful features like a slow clock generator.

Also available with an Uno / Teensy programmer.

$10 for the pololu programmer is a bargain.
Particularly since it comes with the 6 pin header and can also work as a serial port.

Coding..., out of curiosity why would you resort to using an Uno when you have a pololu programmer?
Teensy I understand as it should be faster because of the native USB support, but why use Uno?

--- bill

bperrybap:
$10 for the pololu programmer is a bargain.

Got that right!

Coding..., out of curiosity why would you resort to using an Uno when you have a pololu programmer?
Teensy I understand as it should be faster because of the native USB support, but why use Uno?

Upload performance from fastest to slowest...

• Uno with a 250K baud bootloader

• Pololu (very close to the same speed as above)

• Teensy running TinyISP

• Uno running TinyISP

• Teensy running ArduinoISP

• Uno running ArduinoISP (very slow)

The first two are very close to the programming time listed in the Atmel datasheet and are essentially the fastest possible method using SPI. (Again, I highly recommend the Pololu AVR Programmer. It was worth the $20 I paid for it (now just $10).)

TinyISP on either hardware is not as fast by a noticeable amount but is still fast enough to fall within the "two second" rule1.

ArduinoISP is just abysmal.

I use the Uno or Teensy because of the amenities that I've added to the Arduino ISP sketch (TinyISP is available here). It makes a "good enough" programmer with some very basic debugging tools.

I like the Teensy because, inserted in a breadboard, it makes a very nice "project board". Breadboard + programmer + basic debugging for ~$30. What's not to like?

I like the Uno because it's easier to move from one project to another. Getting the Teensy out of a breadboard is a little annoying.

1 Humans perceive a computer response within two seconds to be reasonable. At five seconds, humans tend to get impatient and annoyed. At ten seconds, they tend to get angry. Past that, the monitor gets a fist, a boot, or a bullet.

why would you resort to using an Uno when you have a pololu programmer?

It's possible to fix the programmer-side firmware when it doesn't work :slight_smile:

@Coding Badly: What are the actual speeds you get? (roughly)

I'm working on a project where I have to upload via ISP (not bootloader) and I am uploading a sketch of 9308 bytes (program memory) or 26208 bytes (hex file size) in 11 seconds, using the Arduino via SD card system I devised.

I don't feel particularly annoyed at waiting that long. That time includes reading the file from SD and checking its integrity, uploading and then verifying the upload. There is an additional overhead of a few seconds to move the SD card from the Mac to the card reader.

Arduino 1.0.1-rc2
avrdude 5.11

Times are reported by avrdude. Rate is bytes per second for a write then verify.

Breadboard Uno running 250K baud Optiboot 4.4 with the Pololu programmer as the USB-to-serial converter: 5313.9

Pololu to an ATmega328P running at 16MHz (2M SPI): 4573.5

Teensy 1 running TinyISP to an ATtiny85: 1628.6

Uno running TinyISP to an ATtiny85: 1481.4

Uno running the stock ArduinoISP to an ATtiny85: 352.4

I'm working on a project where I have to upload via ISP (not bootloader) and I am uploading a sketch of 9308 bytes (program memory) or 26208 bytes (hex file size) in 11 seconds, using the Arduino via SD card system I devised.

846.2 bytes per second.

Gammon Forum : Electronics : Microprocessors : Atmega chip stand-alone programmer to upload .hex files

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

I don't feel particularly annoyed at waiting that long. That time includes reading the file from SD and checking its integrity, uploading and then verifying the upload. There is an additional overhead of a few seconds to move the SD card from the Mac to the card reader.

Dude. You need a programmer. :wink:

OK, well I plugged in my USBtinyISP into the board under test. It has an Atmega32U4 on it, although it isn't a Leonardo. Since that is the same chip as the Leonardo I selected Leonardo in the Boards menu. (It's actually uploading using ICSP not the bootloader / USB interface).

My time to upload and verify was 45 seconds, compared to 11 seconds using my programmer. Maybe the configuration (in boards.txt) can be improved, but so far that is a lot slower. Using USBtinyISP that was only 215 bytes per second uploaded, whereas with my Uno as a programmer it was 879 bytes per second.

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

Are you suggesting a fixed delay?

[quote author=Nick Gammon link=topic=134247.msg1010857#msg1010857 date=1353987137]

pollUntilReady ... that and fixing heartbeat makes the biggest difference to ArduinoISP.

Are you suggesting a fixed delay?[/quote]

No no. The fixed delay is horrible. The Atmel specification calls for a very conservative (read that as "way too long") delay. Polling (when the target supports it) is most definitely the way to go.

ArduinoISP uses a fixed delay which is one of the reasons it's so slow.

[quote author=Nick Gammon link=topic=134247.msg1010857#msg1010857 date=1353987137]

My time to upload and verify was 45 seconds... Using USBtinyISP that was only 215 bytes per second uploaded...[/quote]

Ouch! Dude. You need a better programmer. :smiley:

bperrybap:

sTrider_7:

tim7:
You don't need to remove the bootloader in order to upload Arduino-less code.

Wait what?

The bootloader is just a piece of software that is loaded in the AVR that allows
a tool (avrdude in this case) to upload code to the AVR. The bootloader itself
is totally independent of anything Arduino.

As shipped the AVR fuses are set to create two sections in the FLASH. Bootloader and application.
The "Arduino" bootloader is small piece of code in the AVR that uses the serial port to update the flash
with the user application (code/program/sketch).
The bootloader runs at reset/powerup if there is no attempt to upload anything, the bootloader
will start the application code.
The application code can be written using any toolset you prefer. The Arduino tools are just one option.

avrdude is a tool that is used upload code into the flash.
avrdude can be used with an ISP programmer to upload code to the flash
avrdude can also use other mechanisms like a serial port that talks to a serial based programmer or to a bootloader.
The Arduino IDE uses avrdude to talk over a serial port to a pre-installed bootloader in the AVR chip.
The newer IDE can also use an ISP progammer to upload code. When an ISP programmer is used,
a bootloader is not used so the flash space used by the bootloader code frees up and can be used
by the application code.

If you don't want to use a bootloader, you will need some sort of ISP programmer.
Like Pico, I recommend getting a USBasp programmer off ebay.
I like the USBasp kk multicopter programmers (about $5-$10 USD) because they come with a 6 pin ISP
cable instead of 10 pin so no adapter is needed.

--- bill

This cleared up a lot of things, thank you Bill.