Bootloader

All Round 2 electonics should already have a bootloader loaded, so don't worry about that section unless you are having problems uploading the firmware.

Firmware

Loading the Firmware - the direct way, using pre-compiled firmware

In order to load the firmware, you will need to have power to your OMC board and connect your electronics to your computer using the USB FTDI cable. For instructions on wiring up your electronics, look for the 'Electronics Wiring' page corresponding to the version of your electronics on the 'TVPrusa Design' page.

1. Download and install the Arduino IDE software - use version 0022 from http://arduino.cc/en/Main/Software under 'Previous IDE Versions'
2. Download the Marlin-TVRRUG-v1.2-20130125.hex file at the bottom of this page (right click on it, 'Save target as...'). This is Barnaby's, which should be correct for Round 2, from Google group discussion
3. You upload this to the electronics using the following avrdude command, typed into a Command Prompt (Windows) or Terminal window (Linux/Mac) - avrdude should be in the hardware/tools/ folder of the Arduino IDE software:

   Windows: You'll need to look up what COM port the electronics are attached to in the Device Manager. For example, if it's on COM5:
   avrdude -c wiring -P com5 -p m644 -b 115200 -v -U flash:w:Marlin-TVRRUG-v1.2-20130125.hex

   Ubuntu and Mac: the port may not be 'ttyUSB0'. Change to the correct port if it isn't.
   avrdude -c wiring -P /dev/ttyUSB0 -p m644 -b 115200 -v -U flash:w:Marlin-TVRRUG-v1.2-20130125.hex

4. You may need to put a jumper on the auto reset headers; the ARST jumper (J1) is next to c14 which is adjacent to the coms connector where you attach the serial/usb ftdi cable.
5. You should then be able to connect to the printer at baud rate 115200 with pronterface.

(These instructions need checking, they may be subject to change)

Loading the Firmware - Using Arduino IDE, so you can change the configuration

Setup

In order to load the firmware, you will need to have power to your OMC board and connect your electronics to your computer using the USB FTDI cable. For instructions on wiring up your electronics, look for the 'Electronics Wiring' page corresponding to the version of your electronics on the 'TVPrusa Design' page.

Using the Arduino IDE (Integrated Development Environment, or software!)

Install Arduino 0022

If you do not already have Arduino 0022 installed (you might be able to use v0023, but I had problems with it under Ubuntu, others have reported issues under Windows; use 0022):

1. Download Arduino 0022 from the Arduino website. Do NOT download v1 or later, as this will not work with Marlin firmware.
2. Extract the files.
3. Check Arduino works by running the arduino-0022/arduino file.

Set up Arduino for OMC

Arduino doesn't include the details for the OMC board by default, so we must add them:

1. Download the OMC board definition and extract it to either:
   • arduino-0022/hardware
   • <sketchbook>/hardware - the location of your sketchbook folder is given in the File > Preferences menu within the Arduino application
2. Restart Arduino. Check for the entry 'OMC with Atmega644 at 20MHz' under the Tools > Board menu

Editing and Uploading Marlin

1. You need to download the Marlin firmware. The TVRRUG-modified Marlin source is available at BusError's firmware repository.
2. Open the Marlin.pde file from the downloaded Marlin source files in the Arduino software.
3. Select "OMC with Atmega644 at 20MHz" from the Tools > Board menu.
4. Choose the right port from the Tools > Serial Port menu (in Ubuntu it's usually ttyUSB0, just try USB1 etc. if it's not working).
5. Go to the Configuration.h tab and make any changes you need to, for example if you are calibrating the extruder.
   Round 2 changes: There are 2 changes you need to make to configuration.h for Round 2:
   1. line 35: change the MOTHERBOARD value to 91 - #define MOTHERBOARD 91
   2. line 184: change steps per mm for X and Y axis to 71.1 - #define DEFAULT_AXIS_STEPS_PER_UNIT {71.1, 71.1, 2560, 599.14} // Michel TVRR
6. Verify your changes by hitting the 'Verify' icon (looks like a play sign), or choosing Sketch > Verify/Compile from the menu. Any problems will appear in the console at the bottom of the window - there shouldn't be any
7. Upload firmware to the board:
   1. Put a jumper on the auto reset headers; the ARST jumper (J1) is next to c14 which is adjacent to the coms connector where you attach the serial/usb ftdi cable.
   2. Press the 'Upload' icon, (or choose it from the File menu). Arduino will compile the firmware and then attempt to upload it to the board.
   3. Remove the jumper after successful upload if you plan to print using the SD card. Otherwise the board will reset when you remove the USB lead.

   OR

   1. Hold down the 'Reset' button on the board.
   2. Press the 'Upload' icon, (or choose it from the File menu). Arduino will compile the firmware and then attempt to upload it to the board.
   3. Release the 'Reset' button immediately after the "Binary sketch size:...." message appears in the console, usually a few seconds. If the motors are connected to your board, they will make a 'thud' sound as the board resets, release the button after you hear this sound.

8. You should then be able to connect to the printer at baud rate 115200 with pronterface.

PLEASE NOTE: If you're having issues, restarting the Arduino IDE and re-opening the file to try again is sometimes necessary. Additionally, while calibrating and re-compiling, make sure Printrun/Pronterface or whichever program you're using to control the printer isn't connected and communicating with the electronics while you try to re-upload the firmware, as this seems to inhibit the upload (you'll get an endless number of avrdude timeouts and other errors). Best of all is to just close that program while updating the firmware.