This DIY device is for vibrotactile stimulation and consists of 8 vibration modules and a NodeMCU controller. The frequency, vibration duration, and other settings can be adjusted using a web browser through WIFI. It can be built for less than $20 (access to a 3D printer required).
This device does not have a specific designated use, so it can be used for any purpose of your choice. The initial settings are set to zero, and you will need to adjust them through a graphical interface to your own values.
Please note that this device was built by a hobbyist for personal use only and has not been tested to meet any safety standards or requirements. The code running on the controller may also contain bugs.
The software is likely to be more valuable since it can work with a variety of similar devices. In contrast, the hardware was assembled using whatever materials were available and may require a significant amount of effort to put together, including soldering and gluing. Additionally, the parts used may not be ideal, and I provide some suggestions for improvement throughout the document.
The repository will be updated with more information in the future. If you find it helpful for your own projects, please consider starring the repository. You can contact me at hackydev@gmail.com
The device generates a WIFI network named "vtstim". The default password is 12345678. Upon connecting to this network, you can access the device's settings page by entering "192.168.1.1" in your browser's address bar. From there, you can make various adjustments and update the device in real-time.
The controller utilizes a NodeMCU, which is compatible with Arduino and allows for the reuse of code in your Arduino projects with some modifications. The board in Arduino IDE is NodeMCU 1.0 (ESP-12E Module).
The system is composed of a NodeMCU unit, 8 220 Ohm resistors, 8 DIY vibrotactile modules, 8 1N4007 diodes, and 8 IRF1406 MOSFET transistors, as shown in the schematics below.
I initially utilized BJT transistors, but they resulted in the NodeMCU being unable to boot up. This was due to these transistors grounding certain controller pins, which prevents the NodeMCU from starting up. To address this issue, MOSFET transistors are required.
I haven't included *.stl files for the controller cover because it's unlikely that they will fit your specific controller hardware. However, I have provided a Blender file, so you can make edits and customize it according to your requirements.
The vibration module consists of 3D printed parts, a small 10x10x1 permanent neodymium magnet, and a magnetic coil extracted from a power relay. Assembly can be quite time-consuming. For future versions, I would consider using an audio exciter such as this one
When you print a spring, the printer will pause in the middle of the print to allow you to insert the magnet into the designated hole. Once you have done this, you can resume printing, and the magnet will be securely held inside the spring, eliminating the need for any gluing
The latch on top of the finger module is designed for relatively small fingers. You may need to adjust its height in the provided Blender file. Alternatively, you can place a shim below this part to achieve the desired fit
