OpenAR-M

OpenAR-M glasses.

Welcome to the world of OpenAR-M!

OpenAR-M started as a spin-off of the mainline OpenAR glasses. We wanted to make a more compact sized version of OpenAR glasses that are worn like regular eyeglasses. To do so we had to get rid of all the extra weight of the glasses. As a result, OpenAR-M reflects the image on single eye instead of the previous two eyes.

To minimize the weight resting on the user’s nose, we had to place components to the sides of the head rather than front. This design philosophy brings us back to the OpenAR 1.0 which featured an optical setup with an OLED display and lens on the right side, complemented by a mirror and two reflective glasses at the front. We only made slight modifications by removing one reflective glass and changing the placement of the lens. When the lens is located between the mirror and the reflective glass, we can shorten the distance between the screen and the mirror, so the size of the optics case becomes more compact.

For this version we wanted to come up with some new functionality, so we decided to add a humidity and temperature sensor to the glasses. The sensor reads the temperature and humidity every few seconds and displays the data on an OLED display. The image from the display is optically directed into the user’s right eye, allowing the information to appear within their field of view.

Checking the humidity and temperature of the UEF 3D-printing room with OpenAR-M glasses.

How does it work?

This time we want to reflect light only to a single eye rather than both. The method to do so is the following:

1. Reflect the light emitted by the OLED display by 90° with a first surface mirror.
2. Collimate the reflected light with a lens.
3. Reflect the collimated light again by 90° by using a small rectangular piece of glass.
4. The reflected collimated light now reaches the user’s right eye.

This setup is the most compact because the display and the lens distance must be equal to focal length of the lens. If the lens was between the display and the mirror, the display must be moved further away from the mirror and the size of the optics case increases.

OpenAR-M optical diagram, which is a simplified version of the OpenAR 1.0 optical diagram.

More background information is provided here. Notice that it refers to OpenAR 1.0, but most of it applies to OpenAR-M as well.

How to make it?

To build the OpenAR-M glasses, we used the components listed below. Notice that these are just examples of components that can be used, and it is not mandatory to use the same components. The following links will help you find the components so you can order them or substitute them with other components.

  • The display we used is a 128×64 OLED display.
  • The reflective glass is cut from a thin large plate of clear glass (possibly flint glass) using a glass cutting tool.
  • The lens is a 50 mm focal length lens.
  • The mirror is cut from a rectangular makeup mirror that was bought from our local hardware store. We removed the reflective coating from the back of the mirror to create a first surface mirror, but true first surface mirrors are also available for purchase.
  • The developer board (CPU) we use is an Arduino Pro Mini 3V3 development board which is programmed using Arduino IDE.
  • The battery is a rechargeable 3.7 V 500 mAh LiPo battery.
  • USB-C battery charger LiPo Amigo to charge the battery.
  • Humidity and temperature sensor AM2320.
  • Small parts: For example, M2 bolts x 23 (10 mm), M2 nuts x 5, thin electrical wire, FTDI USB to serial converter etc. Complete list of items and tools are provided in the documentation.

Rest of the OpenAR-M parts, including the frame and the electronics and optics cases, are 3D-printed using black PLA filament. These components may require modifications to ensure a comfortable fit or to accommodate the specific optics and electronics components you are using. 3D-models are provided in the documentation folder as a f3d and stl files. Guide for 3D-printed parts is also included so you can get a brief description of all 3D-printed parts used in OpenAR-M.

If you are not familiar with Arduino programming, there are plenty of tutorials on the internet. We have also created our own Arduino tutorial for version 1.0 glasses, but the principle is the same for OpenAR-M.

Downloads

You can download the OpenAR-M documentation and files here.

Licenses

The OpenAR 3D model files provided in this documentation are under the following license:

OpenAR © 2025 by University of Eastern Finland is licensed under CC BY-NC 4.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc/4.0/

The OpenAR demo programs provided in this documentation are licensed under the Apache License, Version 2.0:

Copyright 2025 University of Eastern Finland

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS ” BASIS , WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.