EZBoard V2 – Bootloader & Pinout Information

This information is provided for people wishing to use 3rd party firmware on the EZBoard V2.

This information is provided as-is with no guarantees or warranty. Do so at your own risk.

If you brick your board by trying to load 3rd party firmware (aka not our Unified 2 Firmware) then it is on you to bail it out, which is usually done with a bootloader re-flash with an STLink programmer.

Bootloader Information

The EZBoard V2 uses an open-source bootloader. This is based on the OpenBLT bootloader code and the source code can be found here: th3dstudio/EZBoardV2-OpenBLT (

There is a 4 pin programming header next to the EXP1 LCD header on the board, this is where the programmer connects to. A simple STLink type programmer can be used to re-program the CPU in the event that you overwrite the bootloader.

Bootloader Offset

The offset for the bootloader is 0xC000. The firmware starts at 0x0800C000.

Bootloader Behavior

If an SD card is present the bootloader will check for a file named firmware.bin. If this file exists it will try to flash it to the CPU and then rename it to firmware.cur.

If the bootloader tries to flash the file it will always rename it whether it was successful or not.

The bootloader only supports flashing from a MicroSD card and not over USB. Firmware like Kilpper has a setting that will send over the firmware.bin to the SD card on the board and then reset the board to flash after it is copied to the SD card. This requires you to leave a small SD card in the slot.

CPU Pin Assignments/Pinouts

Below are pinouts for core parts of our EZBoard V2 from our internal schematic file that would be needed for making configurations.

We do not share the full schematic to make it more difficult for other companies to try and clone our products as we have had this happen in the past by companies in China.

CPU Notes

Our EZBoard V2 uses a 12mhz external crystal.

Header Notes

Neopixel header – This is a simple 3 pin JST-XH header with 5V, GND, and Signal on it. There is no pull-up or pull-down on the signal pin.

Servo header – This is a simple 3 pin JST-XH header with 5V, GND, and Signal on it. There is no pull-up or pull-down on the signal pin.

Endstops (XYZ) – These are simple 2 pin JST-XH headers with GND and signal on them. There are 1K pullup resistors on the signal pins. Pin1 is the Signal pin an Pin2 is the GND pin.

Schematic Pictures

Click on an image to view the enlarged size.

Previous DIY Firmware | EZBoard V2.X Board
Next EZBoard V2 – Installation Guide
Table of Contents