Category: Rebecca’s Status Reports

Report

• I have researched & decided upon specific devices for use in the project. I will need two microcontrollers, a microdisplay, a small camera, and a battery, all of which combined are reasonable to mount to a lightweight headset.
  • The microcontroller I will use for the display is the ESP32-WROVER-E (datasheet linked), via the development kit ESP32-DevKitC-VE. I will additionally use an ESP32-Cam module for the camera and controller.
    • I considered a number of modules and development boards. I decided that it was necessary to purchase a development board rather than just the module as it is both less expensive and will save me time interfacing with the controller as the development board comes with a micro USB port for loading instructions from the computer as well as easily-accessible pinouts.
    • The datasheet for the ESP32-Cam notes that the 5V power supply is recommended, however it is possible to power on the 3.3V supply.
    • The ESP32-Cam module does not have a USB port on the board, so I will also need to use an ESP-32-CAM-MB Adapter. As this is always required, these are usually sold in conjunction with the camera board.
  • The display I will use is a 0.2″ FLCoS display, which comes with an optics module so the image can be reflected from the display onto a lens.
  • The camera I will use is an OV2640 camera as part of the ESP32-Cam module.
  • The battery I will use is a 3.3V rechargeable battery. Likely a Li-PO or LiFePO4 battery, but I need to nail down current draw requirements for the rest of my devices before I finalize exactly which power supply I’ll use.
• I have found an ESP32 library for generating composite video, which is the input that the microdisplay takes. The github is here.
• I have set up & have begun to get used to a ESP32-IDF environment (works on VSCode). I also have used the Arduino IDE before, which seems to be the older preferred environment for programming ESP32s.
• I have begun to draft the CAD for the 3D-printed headset.

Progress Schedule

• Progress is on schedule. Our schedule’s deadlines do not begin until next week.
• I’m worried about the lead time on the FLCoS display. I couldn’t find anyone selling a comparable device with a quicker lead time (though I could find several displays that were much larger and cost several hundred dollars). The very small size (0.2″) seems to be fairly unusual. I may have to reshuffle some tasks around if it does not arrive before the end of February/spring break. This could delay the finalization of our hardware.

Next Week’s Deliverables

• By the end of the weekend (Sunday) I plan to have submitted the purchasing forms for the microcontrollers, camera, and display, so that I can talk to my TA Monday for approval, and the orders can go out on Tuesday. In the time between now and Tuesday, I’ll finalize my battery choice so it can hopefully go through on Thursday, or early the following week.
• By the end of next week I plan to have the CAD for the 3D printed headset near-complete, with specific exception of the precise dimensions for the device mounting points, which I expect to need physical measurements that I can’t get from the spec sheets. Nailing down these dimensions should only require modification of a few constraints, assuming my preliminary estimates are accurate, so when the devices come in (the longest lead time is the display, which seems to be a little longer than two weeks) I expect CAD completion to take no more than an hour or so, and printing doable within a day or so thereafter.
• I plan to finish reading through the ESP32 composite video library and begin to write the code for the display generation so that when it is delivered I can quickly proof successful communication and begin testing.
• I plan to work through the ESP32-Cam guide so that when it arrives (much shorter lead time than the display) I can begin to test and code it, and we can validate the wireless connections.