Which bootloader is on MEGA 2560 R3?

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1

I'm trying to flash a MEGA 2560 with the bootloader of MEGA 2560 R3. I wonder where this bootloader is. I looked in the folders of arduino ide 1.0.x and they all say V2. I have a MEGA 1280 too, any comparable version for this board too? Thanks.

The reason I wanted to upgrade was that using the R3 and arduino official wifi shield I didn't see "SD card not present" error while I regularly see it with the MEGA 1280 and sometimes with MEGA 2560. It's annoying. I had to remove and reinsert the sd card. This is difficult since the sd card points towards the side that is inside my project boxes. I had to open the box to do this.

2

I think the "V2" in the bootloader name is part of STK500V2 (the updated protocol necessary for the larger chips) and not part of "MEGA 2560 Rev2".

The boards.txt file says what bootloader to install and where to find it:

mega2560.name=Arduino Mega 2560 or Mega ADK
mega2560.bootloader.path=stk500v2
mega2560.bootloader.file=stk500boot_v2_mega2560.hex

On my Mac that translates to:
/Applications/Arduino 1.0.5.app/Contents/Resources/Java/hardware/arduino/bootloaders/stk500v2/stk500boot_v2_mega2560.hex

3

Thanks John! Really wish Arduino team implemented better version numbers than v2. The few different v2 firmwares coming with different 1.0.x all have different dates so I can only guess that they are the same due to the v2 designation? Could you recommend a tutorial for flashing the bootloader? I have been using westfw's optiloader for ATMEGA328P-PU and forgot everything I learned about bootloading (I didn't learn much anyway).

4

liudr:
tutorial for flashing the bootloader?

  1. Connect an ISP device to your computer. I recommend the USBasp which you can buy via eBay for less than $4, including shipping! It usually comes with a 10-pin ISP connector and cable. You need to either change one end of the cable to a 6-pin connector or get a 10-pin to 6-pin adapter, also about $4 via eBay. You can't use ArduinoISP for a MEGA because it only does the STK500V1 protocol and the ATmega2560 requires the newer STK500V2 protocol.

  2. Connect the ISP device to the ICSP header on your Arduino board. The header on the board should have a marker for Pin 1. The cable usually has a read stripe on the edge connected to Pin 1.

  3. Select your board in Tools->Boards

  4. Select your ISP device in Tools->Programmers

  5. Select Tools->Burn Bootloader

5

Thanks John! More shopping to do then :slight_smile: