Smol Hardware
📡 Receiver Hardware
It is essential you use boards equipped with high-quality antennas to ensure signal integrity and range. Hardware that features a PCB antenna is generally the best option for use as a receiver.
📡 Receiver Options Ordered By Signal Strength
Nordic Semiconductor nRF52840 Dongle, Seeed Studio XIAO nRF52840 are not included due to lack of data.
- HolyIOT-21017: Reported to have significantly higher signal strength than other options due to included amplifier.
- SuperMini nRF52840 with wire antenna mod
- eByte Dongle (E104-BT5040U): Starts to have issues on distance of 3m, especially when interfered by body parts.
- SuperMini nRF52840
📡 USB Dongles
These dongles have a fairly optimized PCB antenna. If you have issues with signal integrity, it is recommended to use a USB extension cable.
| Dongle | Description | Links | Obtaining |
|---|---|---|---|
| eByte Dongle (E104-BT5040U) |
Cheapest option with a PCB antenna. - E104-BT5040U is the correct model to use. It is fully compatible with the Nordic Semiconductor nRF52840 Dongle. - E104-BT5040UA is not compatible. It is only capable of capturing BLE4.2 and BLE5.0 protocol packets. |
||
| Nordic Semiconductor nRF52840 Dongle (PCA10059) | Official Nordic development hardware. | ||
| HolyIOT-21017 aka HOLYIOT-21017-nRF52840 | Has a FEM (Front End Module), specifically an RFX2401C radio booster. |
📡 Microcontrollers Modified Into USB Dongles
If you plan to use a microcontroller as receiver you can modify it to improve signal strength, replacing the built-in antenna with a 31.2 mm wire. This creates a basic monopole antenna.
| Board | Description | Obtaining |
|---|---|---|
| SuperMini nRF52840 | A clone of the nice!nano board. Cheapest option overall. |
|
| Seeed Studio XIAO nRF52840 | Compact board. |
🏃 Trackers
Before you start, decide on how many trackers you may need.
Trackers are required to have a battery and an inertial measurement unit (IMU). A magnetometer is optional.
Buttons and slide switches are recommended but not required. Buttons can be added to control the tracker, and a slide switch can be used to physically disconnect a tracker's battery.
📻 Microcontroller Boards
| Board | Description | Obtaining |
|---|---|---|
| SuperMini nRF52840 |
A clone of the nice!nano board. Cheapest option overall.
Signal strength can be improved with antenna mod. |
Available on AliExpress with compatible with nice!nano or Pro Micro branding.
|
| Seeed Studio XIAO nRF52840 | Compact board. |
🧭 Inertial Measurement Units
Some of the supported sensor modules are described on the IMU Comparison page.
- BMI270
- ICM-42688-P
- ICM-42688-V
- ICM-45686
- ISM330BX
- ISM330DHCX
- ISM330DLC
- LSM6DS3
- LSM6DS3TR-C
- LSM6DSL
- LSM6DSM
- LSM6DSO
- LSM6DSR
- LSM6DSV
- LSM6DSV16B
🧲 Magnetometers
- AK09940
- BMM150 Sensor driver has not been tested.
- BMM350 Sensor driver has not been tested.
- IIS2MDC
- IST8306
- IST8308
- LIS2MDL
- LIS3MDL Sensor driver has not been tested.
- MMC5983MA
🟩 Sensor Modules with IMU and Magnetometer
Meia IMU + Magnetometer Modules
Meia, a member of the SlimeVR Discord, produces and sells IMUs with an onboard magnetometer suitable for stacked builds.
| IMU + Magnetometer | Product Page |
|---|---|
| ICM-45686 + IST8306 | store.kouno.xyz |
| LSM6DSR + IST8306 | store.kouno.xyz |
🖲️ Buttons
Push buttons and momentary switches are utilized to control the tracker. The functions of this button—Reset, Calibration, Pairing, Deep Sleep, and entering DFU Mode—depends on the number of press combinations. A tracker can be equipped with either a reset button, a user-specified (SW0) button, or both.
The reset button is designed to support all functionalities. If an user-specified button (SW0) is defined, it will be utilized instead.
If a button is unavailable, tweezers can be used to short the pins for the initial tracker setup.
🕹️ Switches
A slide switch can be used to physically disconnect a battery. Some boards have a high standby power draw and will require a switch.
If a switch is not utilized, a tracker can enter Deep Sleep mode by pressing and holding down the user-specified button (SW0).
🔋 Batteries
Safe battery charging rates (C) are correlated to their rated capacity (mAh). A 100mAh battery charging at 100mA is 1C, and a 200mAh battery charging at 100mA is 0.5C. Charging at lower rates near 0.5C is recommended to reduce battery stress and extend lifespan.
| Board | Default charge rate | Minimum battery capacity | Recommended battery capacity |
|---|---|---|---|
| Seeed Studio XIAO nRF52840 | 50mA | 50mAh | 80-300mAh |
| SuperMini nRF52840 | 100mA | 100mAh | 180-300mAh |