How to Flash A Bootloader and Firmware on Ender 3 Motherboard 1.1.4

The latest Ender 3 3D Printers are being shipped with the version 1.1.4 Motherboard, and the instructions online for flashing the bootloader have the wrong ISP pin diagrams. I have decided to write my own how-to and inform you guys how to get the ISP header pins lined up correctly with your Arduino.

Tools Required to Flash Bootloader & Firmware

  1. Arduino Uno or Clone
  2. Male to Female Dupont Jumper Pins
  3. Mini-USB to USB Cable (I recommend the one with Ferrite Core to avoid noise, see link)
  4. Marlin 1.1.9 Bugfix or TH3D Firmware
  5. Window’s Arduino IDE (Click to download pre-configured portable version) Alternate Mirrors:

First, you will need to get your Arduino IDE opened up, and open the firmware you will be using (Marlin or TH3D) if you have chose our pre-configured Marlin you only need to open it by finding the folder you extracted and opening the file “Marlin.ino”. If you have chose to install the TH3D firmware, you need to open “TH3DUF_R2.ino” and un-comment the printer you will be using (Ender 3 in this case). Don’t forget to choose the Sanguino 1284p board in the Tools drop-down menu on Arduino IDE, and then choose to Verify/Compile the firmware under Sketch menu to ensure you haven’t made any errors.

Next you will need to open up the motherboard cover on your Ender 3, there are 3 metric allen screws in the top. Once the 3 screws are loose, be careful because your fan is attached to the cover and there are wires hooked onto the motherboard. Then you need to attach your Male to Female Jumper Pins from the ISP header on the Arduino to the Control Board. The easiest way to line this up is to look at the Arduino, and find the ISP text on it, and find the ISP writing on your Ender control board; Then you will put the Arduino into the same orientation so that both boards ISP font is facing the same way, and align the jumpers pin to pin. The only pin that doesn’t line up directly is the RESET pin, or the bottom left pin on the control board; It should be routed to your Arduino Digital PIN 10.

Once your pins are connected, you will look in the Arduino IDE under Tools for “Burn Bootloader” and you will need to verify that “Arduino as ISP” is chosen. Click on the Burn Bootloader button, and wait for it to finish. If you get an error; verify that all your pins are on correctly and try again. Once the bootloader is burned, you can disconnect the pins from the motherboard and remove the USB cable from your PC. You will now need to hook up the USB to Mini-USB from your PC to your Printer.

Now that you have burned the bootloader onto the firmware, you can verify that you have chose the “Sanguino 1284p” board under Tools > Board. You will also verify that the correct Port is chosen for the USB to Mini-USB, and then choose the “Upload” button under Sketch menu.

The firmware should upload within a few moments, and you should see the “done” status in the bottom command prompt. The printer will reboot, and you will now have your new firmware installed. Now you can enjoy the Manual Mesh leveling if you chose our Pre-configured Marlin or you can use TH3D’s options as well. Have questions or issues? Leave a comment or send us an email for help.

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thanks. Your choice of red font in the ISP pin photo is just bad

Bryan Hearn

I upgraded the motherboard and it does not a bootloader, yet I can not get Marlin to program it. Any thoughts???

Bryan Hearn

Does not NEED a bootloader.

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