Installing a bootloader on a BIGTREETECH SKR v1.3

I have seen a few requests for this info but no answers. So I thought I would document it here (since I just needed to do this)

It is identical to flashing a boot loader on a smootheboard but with different pins and a additional switch, see smootheboard docs here

You need a device to act as a USB to logic levels serial converter.
The serial pins on the SKR 1.3 are listed as being 5v tolerant but I used a 3.3v capable FTDI converter, just to be safe.

You also need something to act as a normally open switch .
Connect the two leads of the switch to the two pins of the BOOT Jumper on the SKR 1.3 (under the ZUART pins)

Connect the following FTDI pins to the SKR 1.3 (you can use the TFT connector or the AUX-1 for this, I used AUX-1)

FTDI GND   ->  AUX-1 pin 4 GND  
FTDI RX    ->  AUX-1 pin 6 TX
FTDI TX    ->  AUX-1 pin 8 RX

If your confused about which pins are what, they are labeled on the bottom of the PCB.

Now perform the following Incantation

Power on the SKR 1.3 (I have the power jumper for 5v set to USB, so all I needed to do was plug in the USB cable)
Press and hold the RESET button
Press and hold the BOOT button (the switch you added)
Release the RESET button
Release the BOOT button (the switch you added)

The controller is now waiting for data over the serial port

Plug the FTDI into your computer and identify what serial port is come up as. (I'm using Linux and its shows as /dev/ttyUSB0)

Now you will need some software. See [smoothieware.org] for what you need for your operating system.
You also need a bootloader from the above link.

Since I'm using Linux I used the command: "lpc21isp -wipe DFU-Bootloader.hex /dev/ttyUSB0 230400 12000"
The output was

lpc21isp version 1.97
File DFU-Bootloader.hex:
	loaded...
Start Address = 0x000000CD
	converted to binary format...
	image size : 13944
Image size : 13944
Synchronizing (ESC to abort). OK
Read bootcode version: 2
4
Read part ID: LPC1768, 512 kiB FLASH / 64 kiB SRAM (0x26013F37)
Will start programming at Sector 1 if possible, and conclude with Sector 0 to ensure that checksum is written last.
Wiping Device. OK 
Sector 1: ..............................................................................................
Sector 2: ..............................................................................................
Sector 3: ..........................................
Sector 0: ..............................................................................................
Download Finished... taking 7 seconds
Now launching the brand new code

Reset the controller to make sure its running new bootloader.

The bootloader has been reinstalled.

Then you drop a firmware.bin on the SD card to install the firmware like normal.

Edited 2 time(s). Last edit at 11/30/2019 10:05AM by Dust.

Thanks for posting this, hopefully I'll never need to install a bootloader but good to know how if the need arises.

A word of warning.

Without a running firmware the controller doesn't work as a usb/sd card reader/writer. The operating system will not see the SD card or the usb serial port.

You need to upload the firmware.bin to the sd card via some other method.

Hi
Where on SKR 1.4 can i find BOOT Jumper ?

The 1.4 circuit diagram shows the pin is tied to 3.3v via a 10k resistor R28... It look like you would need to remove this resistor.
One side of the resistor is 3.3v, the other is the boot pin.
Its above to top right corner of the lcp1768/9

I don't have a actual 1.4 board to confirm this

Edited 1 time(s). Last edit at 05/12/2020 04:52AM by Dust.

Thank you very much! My SKR v1.3 was a brick in cyclic restart

I have started a repo of all BIGTREETECH bootloaders. I have ripped them from the boards I own. If I do not have the board I will get one in. But while I wait for boards I have found bootloaders on the web.

I hope this resource is helpful:
[github.com]

I have also provided manual on how to backup and restore bootloader/Marlin firmware:

This PDF will describe all the bootloaders I am trying to place in the repository and where the bootloader resides on each BTT board: [github.com]

GUIDE for UART flashing the LPC17xx Processor using the BTT writer:
[github.com]

Another GUIDE for UART flashing LPC17xx Processor that uses the USB to TTL serial cable/adapter:
[github.com]

GUIDE to UART Flashing the SKR E3 TURBO board (LPC1769) with a new compiled bootloader:
[github.com]

GUIDE for STM32 processor with ST-LINK:
[github.com]


Maybe this can help others with the problem.