Sologear G3-15 Electric Unicycle reverse engineering to reuse motherboard with custom firmware. Schematics of other generic cheaper electric unicycles (monowheels) should be same/similar. Let us know in the issues.
Install Platform IO extension in VS Code. Open firmware folder in VS Code Connect programmer (without connecting 3.3V) Switch monowheel on
Monowheel folder contains KiCad files for the monowheel.
| Pin | Marking | Comment |
|---|---|---|
| 1 | 5V | |
| 2 | Not connected | |
| 3 | SPK |
Connected in parallel with buzzer
| Pin | Marking | Comment |
|---|---|---|
| 1 | 5V | |
| 2 | ||
| 3 |
| STM32F103C8T6 | Hall sensor | Color | Comment |
|---|---|---|---|
| 1 | Black | GND | |
| PA0 | 2 | Blue | |
| PA1 | 3 | Yellow | |
| PA2 | 4 | Green | |
| 5 | Red | 5V |
From switch to charging connector: 1 - 4
| STM32F103C8T6 | P4 Battery Indicator | Color | Comment |
|---|---|---|---|
| PA15 | 1 | Black | Via resistor R1 |
| PB4 | 2 | Blue | Via resistor R2 |
| PB5 | 3 | Yellow | Via resistor R3 |
| PB8 | 4 | Green | Via resistor R4 |
| 5 | Red | +5V |
| Pin | Marking | Comment |
|---|---|---|
| 1 | PA4 via R6 10k resistor | |
| 2 | GND |
| Pin | Marking | Comment |
|---|---|---|
| 1 | +60V | |
| 2 | To board |
| STM32F103C8T6 | SWD |
|---|---|
| PA14 | SWC |
| PA13 | SWD |
| 3V3 | |
| GND |
| Step | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| High | A | B | B | C | C | A |
| Low | C | C | A | A | B | B |
| H1L3 | H2L3 | H2L1 | H3L1 | H3L2 | H1L2 |
https://www.digikey.be/nl/articles/what-is-the-most-effective-way-to-commutate-a-bldc-motor https://www.digikey.nl/en/blog/using-bldc-hall-sensors-as-position-encoders-part-1
| U | V | W | Step | |
|---|---|---|---|---|
| 1 | + | - | off | 6 |
| 2 | + | off | - | 1 |
| 3 | off | + | - | 2 |
| 4 | - | + | off | 3 |
| 5 | - | off | + | 4 |
| 6 | off | - | + | 5 |
| A | B | C |
| STM32F103C8T6 | MPU 6050 | Comment |
|---|---|---|
| PB7 | SDA | Via resistor R31 |
| PB6 | SCL | Via resistor R33 |
Half-Bridge Driver connections
| STM32F103C8T6 | IRS2108 |
|---|---|
| PB10 | HIN1 |
| PB09 | HIN2 |
| PB08 | HIN3 |
| PB15 | LIN1 |
| PB14 | LIN2 |
| PB13 | LIN3 |
Existing firmware was unprotected and could be read using STM-Link V2. Soldering headers was a bit difficult as pin holes were already filled with solder.
STM32F103C8T6
InvenSense MPU 6050
6 MOSFET ST P75NF75&
IRS2108 Half-bridge Driver 8-Lead SOIC
59.2V/4.4Ah 260Wh SAMSUNG/22PM
Hy-LYX-1602B-22PM-144900042
CST e-BIKE PRO Li-ion Electronic
14AMK1512615052
XINAOMA
STM32 ST-LINK Utility
Ghidra with SVD-Loader
| Marking on board | Connections | Connected |
|---|---|---|
| P2 | 2 | 5v SPK Unpopulated |
| P3 | 3 | 2p connected to switch LED |
| P4 | 5 | 2mm: battery level |
| P5 | 5 | 2.5mm: hall effect sensor |
| P6 | 2 | Disconnected |
| P7 | 2 | Switch |
| Marking on board | Color | Switch |
|---|---|---|
| P3 | Red | |
| P3 | Black | |
| P7 | Red | |
| P7 | White | Center |
Red Black Connected to battery
| Color | Marking on board |
|---|---|
| Yellow | Y? |
| Green | V |
| Blue | W |
??? GND 3.3V