a5:bootloader

Flashing a new bootloader on the A5/A3S

In some circumstances, a firmware flash may fail half way, which will cause the motherboard to “lose” its bootloader. The bootloader is a part of the firmware that allows the motherboard to be upgraded over USB. Without the bootloader, the firmware must be flashed using the ICSP programming port.

The bootloader can be reinstalled using either a USB programmer device, or using an arduino device.

Flashing bootloader using USB Programmer

The simplest process.

  1. Connect programmer to computer
  2. Connect programmer to motherboard
  3. Open Arduino IDE
  4. Select the programmer you use in the Tools → Programmer menu
  5. Choose “Burn Bootloader” in the tools menu
  6. Go back to normal life, flashing via USB cable direct to your 3D printer.

PLAN A: Flashing bootloader using Arduino UNO or Arduino MEGA - Method 1

Don't have a USB programmer lying around? Feeling like you would like to buy an arduino for future projects anyway? Read on…

You can use an Arduino as a USB programmer fairly easily!

Download and flash this awesome arduino bootloader flasher by Nick Gammon.

All your pins on the MKS Gen L should be connected to the ICSP port (see first image below).

  1. Connect pin 10 on the uno to the RST on the MKS Gen L ICSP port (see image #2 for pinout)
  2. Connect MISO, MOSI, SCK, VCC, GND to the matching pins on both MKS ICSP and uno ICSP headers.
  3. Flash the bootloader sketch.
  4. Open the arduino serial monitor.
  5. You may need to choose the correct baud rate to see text correctly.
  6. Follow the prompts in the serial monitor.

PLAN B: Flashing bootloader using Arduino UNO or Arduino MEGA - Method 2

Don't have a USB programmer lying around? Feeling like you would like to buy an arduino for future projects anyway? Read on…

You can use an Arduino as a USB programmer fairly easily!

Please read this article first for the main guide. We need to do three things:

  1. Install the bootloader flashing sketch onto the arduino device you will be using, using USB cable from computer to arduino
  2. Connect the cables between arduino and the MKS motherboard in the A5
  3. Flash the bootloader using the Arduino IDE software.

For step 1, you need to flash the programming sketch to the arduino. See “Load the sketch” at the link above.

For step 2, you need to wire up the device. See the link above if you have an arduino uno, or nano. If you have an arduino MEGA, the pins are different - use the wiring here]

You may have to connect a jumper from ground to reset on the arduino, to prevent it being reset during flashing.

for step 3, make sure to cross your fingers and toes.

Once you have flashed the bootloader, you can flash the firmware using your usb cable directly to the printer. Don't forget to follow all the instructions!

a5/bootloader.txt · Last modified: 2018/10/18 23:08 by samuelpinches