GeekIMU/1.Hardware/GeekIMU-Wireless/README.md

# Marzipan

![sample](./assets/sample.jpg)

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  English | <a href="./README_CN.md">简体中文</a>
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A compact and easy soldering modular Smol Slimes / nRFSlime solution with dimensions of 40x28x17mm!

If you'd like to learn more about Smol Slimes / nRFSlime, feel free to read the [Smol Slime - SlimeVR Docs](https://docs.slimevr.dev/diy/smol-slime.html).

>[!CAUTION]
>The current version (1.1) has the following issues:
>
>- When using the ICM-45686 module from LWKJ, the sensor cannot be detected upon powering up the switch; you’ll need to press the button again to start it properly.
>- The button's functionality does not behave as expected.
>
>Pull Requests are welcome to help fix these issues!

## Description

### PCB

The PCB is designed using the **EasyEDA** Pro version, and the repository provides the source files for further modification.

For different pre-made sensor modules, I’ve created the following PCBs for different types. However, due to time constraints, only the `VGGALXI` version has been verified. The others should theoretically work.

- **`VGGALXI`**: Pin order from bottom to top is `VCC GND GND SDA SCL X INT` (**verified**)
- **`VGLAXXI`**: Pin order from bottom to top is `VCC GND SCL SDA X X INT` (**not verified**)
- **`KOUNO'S_ICM45`**: Designed for KOUNO's module (**not verified**)

### Case

For the case, two versions are provided:

- **`Case_v5.stl`**, which requires M2 heat insert nuts.
- **`Case_v5_No_Heat_Insert_Nut.stl`**, where screws can be directly fastened into the case.

The version with heat insert nuts is more durable.

For Bambu Lab printers, pre-configured printing settings are provided here.

**https://makerworld.com/zh/models/966982**

The case files in the repository are designed to fit **25mm-wide straps** and are also compatible with ReboCap’s quick-release system.

If you prefer wider straps, feel free to modify the `.step` source files.

### Firmware

The pin positions of this PCB match the default layout in the original project (`SDA-006`, `SCL-008`, `INT-017`), so you can directly flash the firmware provided on the [Smol Slime Docs](https://docs.slimevr.dev/diy/smol-slime.html) without additional changes.

## BOM

### PCB and Assembly

The table below shows the components needed for **one tracker**. Note that you’ll also need to purchase one **nRF52840 SuperMini/Dongle** as a receiver. For more details, refer to the Smol Slime page.

According to the Discord community, one receiver can pair with approximately **20 trackers** (this hasn’t been fully tested, but it should work for at least 6).

|         Component         |  Qty  |               Notes                |
| :-----------------------: |  :--: | :--------------------------------: |
| nRF52840 SuperMini Board |    1   |                                    |
| MSK-12D19 Slide Switch |   1   |     A legacy switch; other switches may also work     |
|  3*6*4.3 Tactile Switch (Side)  |   1   |     Other side tactile switches can also be used     |
| 401230 / 501230 Battery |   1   | 501230 is recommended; smaller batteries are also fine |
| Double-sided tape for battery |   1   |                |
|   Sensor Module |    1   |                                    |
|        M2*14 Screws        |   2   |            Used to secure the case            |
|    M2*4.5*3 Heat Insert Nut    |   2   | Not needed for the screw-only case version |
| 25mm-wide strap | 1 | You can modify the case files for other straps |

### 3D Printing

For 3D printing, PETG is recommended, but PLA is also fine.

|    Component    | Qty  |                            Notes                             |
| :-------------: | :--: | :----------------------------------------------------------: |
|     Lid_v5      |  1   |                           The lid                            |
|     Case_v5     |  1   | Case body that requires heat insert nuts; use `Case_v5_No_Heat_Insert_Nut` if not needed |
|  Button_Cap_v5  |  1   |               Button cap for extending buttons               |
|  Switch_Cap_v5  |  1   |              Switch cap for extending switches               |
| Screw_Holder_v5 |  2   |   Screw support pillars; optional but increases durability   |

## Assembly Instructions

### Soldering and Assembly

- (Optional) Use a probe or other tools to check if the SuperMini, sensor module, etc., are functioning properly.

- **Solder the sensor module first**:
  - Make sure the sensor’s pin order matches the PCB.
  - Align the pins and secure them by melting solder from the back of the PCB. After soldering, use a multimeter to ensure the circuit is properly connected.

- Solder the switch and button.

- Make sure the switch is in the OFF position, then solder the battery.

- Finally, solder the SuperMini module.

- After confirming normal functionality, stick the battery to the back of the PCB using double-sided tape in the designated rectangular area.
- Embed the heat insert nut into the Case.

- Install the button and switch caps into the case, align the holes, and insert the main body into the case.

- Insert the screw support pillars, attach the lid, and fasten the screws.

### Flashing Firmware

- Refer to the [Smol Slime Docs](https://docs.slimevr.dev/diy/smol-slime.html) for instructions on flashing firmware.
  - When using **LWKJ's ICM-45686 module + `VGGALXI` layout**, the firmware configuration `Tracker SuperMini Disabled Disabled` works properly.


## Links

- **SlimeVR nRF Receiver Firmware:** https://github.com/SlimeVR/SlimeVR-Tracker-nRF-Receiver

- **SlimeVR nRF Tracker Firmware:** https://github.com/SlimeVR/SlimeVR-Tracker-nRF

- **Scawanf's PCB R3 on Github:** https://github.com/SlimeVR/SlimeVR-Tracker-nRF-PCB

- **Scawanf's PCB R3 on OSHWLab:** https://oshwlab.com/sctanf/slimenrf3

- **SlimeVR Discord:** https://discord.gg/SlimeVR

- **Smol Slime Docs:** https://docs.slimevr.dev/diy/smol-slime.html