Mi Scooter Pro 2 downgrade firmware

Disclaimer These instructions do not purport to cover all required preconditions, necessary downgrading steps and do not claim to provide for every possible contingency met during downgrade process. Should further information be desired or should particular problems arise which are not covered sufficiently for you, the matter should be referred to here and here

Intro

I had updated a firmware on my Mi Electric Scooter Pro 2 via Mi Home app. Then I found out that this update blocked possibility to install any custom firmware via bluetooth. That’s why I need to do downgrade process first.

Scooter info

First of all I gathered hardware and firmware version info to understand whether it is possible to downgrade and decide which tools to use.

• Mi Home¹
  • Firmware version: V2.4.8 (1.1.0_248_157_141)
  • Production date: 12/04/2021
• Scooter hacking utility (SHU)²
  • Model: Mi Electric Scooter Pro 2
  • BLE: 1.5.7
  • DRV: 2.4.8
  • BMS: 1.4.1
  • UUID: FF**********************
• Dashboard
  • SCO_BLE_V3.3
  • CD.00.0011.90

I carefully read several forums (two of them already mentioned in disclaimer) to be sure that my scooter fits and chose ST-LINK/V2 programmer with MiDu-Flasher³ tool for Windows pc.

Scooter preparation

Scooter must be fully charged and switched off. Remove dashboard cover and solder three male-female jumper wires to the points on the board shown in the figure.

Switch on the scooter and lock it via bluetooth app.

Software preparation

Download and unzip MiDu-Flasher. Install driver .\Driver\ST-LINK_USB_V2_1_Driver\stlink_winusb_install.bat, plug in ST-Link programmer and upgrade its firmware with .\Driver\ST-LINK_FirmwareUpgrade_V2.J37.S7\ST-LinkUpgrade.exe

Downgrade

*************************************************************************
 *                       ____________________________                    *
 *                      /                           /\                   *
 *                     /       MiDu-Flasher        / /\                  *
 *                    /  Mi Downgrade & Unbrick   / /\                   *
 *                   /       ST-Link Utility     / /\                    *
 *                  /___________________________/ /\                     *
 *                  \___________________________\/\                      *
 *                   \ \ \ \ \ \ \ \ \ \ \ \ \ \ \                       *
 *                                                                       *
 *                      powered by OpenOCD                               *
 *                      created by VooDooShamane                         *
 *                      support Rollerplausch.com                        *
 *                                                                v1.0.5 *
 *************************************************************************
 -------------------------------------------------------------------------
 | Target=Dashboard  | Action=Downgrade   | Scooter=Pro2 | Chip=N51822x  |
 -------------------------------------------------------------------------

spoof new BLE to 157 ? (recommended)
Press [y] to spoof and [n] to leave BLE untouched

Launch MiDu-Flasher, select these four settings

• Target = Dashboard
• Action = Downgrade
• Scooter = Mi Pro2
• Chip = NRF51822QFAC (32kb RAM)

The program will complain that it cannot find the necessary files and will offer to download them. Agree. The last question is about spoofing BLE version. Answer NO to be able flashing with SHU app later.

From now there are 40 seconds to connect soldered wires to ST-Link.

MiDu-Flasher will establish a connection and start downgrade. Keep calm until the process is complete.

That’s all! It’s possible now to cook custom firmware here: https://mi.cfw.sh/ and flash via bluetooth with SHU app.

Speed limit unlock example

Footnotes

1. Mi Home - Xiaomi Smart Home App Store ↩

2. ScooterHacking Utility Google Play ↩

3. MiDu-Flasher GitHub ↩