OpenAR 2.1

Built upon the OpenAR 2.0 platform, OpenAR 2.1 aka “thermal glasses” enhance the user’s vision by detecting infrared radiation. Live video feed of heat sources in front of the thermal camera is reflected onto the user’s eyes, effectively broadening the electromagnetic spectrum visible to humans.

*OpenAR 2.1 closely resembles its predecessor*.

New and upgraded 3D models, a more powerful CPU, a thermal camera, and a fresh new paint job. OpenAR 2.1 is a prime example of how small changes to electronics, and the 3D models can change the functionality of the OpenAR platform. Previously, we only had a demo-program that showcased the augmented reality effect. Now we have actual functionality! You can use the 2.1-glasses to find heat sources around you as a fun experiment.

*Thermal camera image of a hand captured with a phone camera. The user experience is much more immersive!*

OpenAR 2.1 has the same optics and overall design as the 2.0 version. Changes were made mainly to the electronics to run the thermal camera live feed. New 3D models were also made and printed to fit these new electronics onto the optical and headband setup. The cool thing (no pun intended) about the thermal camera C++ program (written with VS code) we provide, is that you can easily change the minimum and maximum temperature that is drawn onto to the LCD display. In the thermal image above, you can see how the sunlight coming through the windows warms the air in the room. Changing the minimum value by a few degrees would clean up the image.

*The same optical setup as in OpenAR 2.0 with the added thermal camera.*

How it works

The optics are the same as in OpenAR 2.0. We simply added the thermal camera on top of the optical setup and programmed an ESP32 FeatherS3 development board to show the live feed on the LCD display.

*A top-down look at the optical path light takes from the display to the user’s eyes*.

The LCD display we use is a 240×240 1.3-inch LCD display.
The two reflective glasses are cut from a thin large plate of clear glass (possibly flint glass) using a glass cutting tool.
The lens is a +3.5-diopter lens taken from a pair of reading glasses that were bought from our local hardware store.
The mirror is cut from a rectangular makeup mirror that also was bought from our local hardware store.
The developer board (CPU) is an ESP32 FeatherS3 which is programmed using Visual Code. We replaced the STM32 Blue Pill with the FeatherS3 as the thermal camera requires a bit more processing power. Great thing is that FeatherS3 has an in-built charger and voltage regulator, so overall we need less components for OpenAR 2.1.
The thermal camera is a Grove Thermal Imaging Camera MLX90640. The compact design of the camera fits perfectly with the OpenAR platform, as we only needed to 3D model a casing and a mount for the camera. The camera has a resolution of 32×24 px with a field-of-view of 55° x 35°.
The battery is a rechargeable 3.7 V 1500 mAh LiPo battery with an integrated Protection Circuit Module (PCM) bought from a hardware store. The battery can be charged through the FeatherS3 board.

The circuit diagram is included in the OpenAR 2.1 documentation. Note that the optical and headband setup are almost identical to OpenAR 2.0. For this reason, the written documentation only contains what is new in OpenAR 2.1 and OpenAR 2.0 documentation is still the go-to for full assembly instructions. Click to view and download the OpenAR 2.0 documentation.

All the 3D models, f3d files, and the thermal camera program for OpenAR 2.1 can be downloaded below.

Downloads

You can download the OpenAR 2.1 documentation and files here.

Licenses

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

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

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 http://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.