

MaskMoji
A way to let people see your facial expressions through a mask
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 11
- Nets
- 87
- Pads
- 115
- Tracks, vias
- 0, 0
- Routed
- Not yet
- KiCad
- KiCad 5 (file 20171130)
- Created
- 13 Sep 2020
- Updated
- 28 Nov 2020
Overview
MaskMoji is an open-source printed circuit board by rmd6502, from the rmd6502/MaskMoji repository on GitHub. It is a 2-layer board with 11 parts on 87 nets.
It is built around the CH330N, ESP32-WROOM-32 and BQ24075RGT, with the LM1117-3.3 and PZT2222A among its other parts. Its parts include 4 resistors, 4 ICs, 2 connectors and 1 transistor. It belongs with the ESP32 boards of this library.
Main components
5CH330N
SOP-8-20℃~+70℃ 15mA 2Mbps 3.3V、5V Transceiver SOP-8 USB Converters ROHSWCH (Nanjing Qinheng Microelectronics)USB ConvertersESP32-WROOM-32
SMD,18x25.5mm-40℃~+85℃ -98dBm 2.4GHz 2.7V~3.6V 20dBm Bluetooth4.2 ESP32-DOWDQ6 UART、SDIO、SPI、I2C、GPIO、PWM、ADC、DAC SMD,25.5x18mm WiFi Modules ROHSEspressif SystemsWiFi ModulesBQ24075RGT
QFN-16-EP(3x3)-40℃~+125℃ 1.5A 4.2V 4.35V~6.4V 6.5uA Charging IC Lithium Battery Not supported Support QFN-16-EP(3x3) Battery Management ROHSTexas InstrumentsBattery ManagementLM1117-3.3
SOT-2231 1.3V@(1000mA) 15V 1A 2mA 3.3V Fixed Over Current Protection、Short Circuit Protection、Thermal shutdown Positive SOT-223 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHShongjiachengUncategorisedPZT2222A
SOT-223-55℃~+150℃ 1 NPN 1.5W 10nA 300MHz 300mV 35 40V 600mA 6V NPN SOT-223 Bipolar (BJT) ROHSonsemiBipolar (BJT)
README
README.mdMaskMoji
A way to let people see your facial expressions through a mask
Instructions
I based my build on the LilyGo TTGO since it had everything I needed on the board already.
Git clone or download and unpack this repository to a convenient location.
Prepare the board
You'll need to purchase a small square or rectangular rechargable lithium ion battery, for example. While you're there, maybe buy four magnets to help hold the assembly to your mask.
The battery comes with a 1mm or 2mm connector, but the TTGO comes with a 1.25mm connector. You'll need to clip off the leads and solder on the 1.25mm connector. Be careful not to short the battery while doing this.
I 3D printed an enclosure which holds the board and battery and protects the screen from cracking.
Download and install the Arduino IDE, the ESP32 board support, and the SPIFFS Filesystem loader.
Open the Arduino IDE, and install the plugins above if you haven't already. Go to Tools->Library Manager and search for and install the Adafruit ST7789 library and its dependencies. Install the TJpg decoder.
Go to Tools->board and select ESP32->ESP32 Dev Board. Go to Tools->Partition Scheme and select "No OTA (1MB App/3MB SPIFFS)". Don't select the 3MB FAT option, that won't work.
You'll need to thin out the data directory to make it fit in 3MB. If you have the 16MB version of the TTGO and are feeling brave, you can modify {ARDUINO_ROOT}/packages/esp32/hardware/esp32/1.0.4/boards.txt and find the 7MB SPIFFS option and move it to the description for the ESP32 dev board.
Open the Maskmoji firmware at (unpack directory)/Firmware/MaskMoji/MaskMoji.ino . Click the check mark icon at the top left to build and make sure it succeeds.
Plug in your board. Go to Tools->Port and select the COM or /dev/tty that corresponds to your board.
Click the arrow icon to the right of the checkmark icon, this should upload the firmware to your board. Assuming you installed the ESPFS loader, go to Tools->ESP32 Sketch Data Upload. This uploads the Emoji images to the flash memory.
iPhone App (No Android App yet)
If you have a mac, you can build and install the app via XCode. If not, I'll eventually have something on the App Store.
Usage
Open the MaskMoji app on your iPhone. Plug the battery into your board.
Select "Scan" in the upper right. You should see your maskmoji. If there are multiple, press the button on the same side as the reset button to see your maskmoji's ID. Select your maskmoji. You'll return to the emoji grid.
Click an emoji to display it on the screen!
Parts
11| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | R | Resistor_SMD:R_0603_1608Metric | R1, R2, R3, R4 |
| 1 | BQ24075 | Package_DFN_QFN:QFN-16-1EP_3x3mm_P0.5mm_EP1.75x1.75mm_ThermalVias | U2 |
| 1 | CH330N | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U1 |
| 1 | Conn_01x02 | Connector_JST:JST_EH_S2B-EH_1x02_P2.50mm_Horizontal | J2 |
| 1 | Conn_01x22 | Connector_FFC-FPC:TE_2-1734839-2_1x22-1MP_P0.5mm_Horizontal | J3 |
| 1 | ESP32-WROOM-32 | RF_Module:ESP32-WROOM-32 | U3 |
| 1 | LM1117-3.3 | Package_TO_SOT_SMD:SOT-223 | U4 |
| 1 | PZT2222A | Package_TO_SOT_SMD:SOT-223-3_TabPin2 | Q1 |
Questions
What parts does the MaskMoji use?
11 parts, built around the CH330N, ESP32-WROOM-32, BQ24075RGT and LM1117-3.3. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the MaskMoji KiCad files?
From the rmd6502/MaskMoji repository on GitHub, at the commit this page was made from: the board is Hardware/maskmoji.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the MaskMoji design in my own project?
Its repository states no licence, so its author keeps all rights: ask rmd6502 before reusing the design.
Similar boards
- 2 layers70 × 33 mm

- 2 layers60 × 40 mm

Forcegauge
szbeni/forcegauge
Traning for climbing. Load cell with HX711 and real time plotting,
77 parts18GPL-3.0 - 2 layers43.8 × 25 mm

Calve heater
R-Mutura/calve_heater
Hardware and software Implementation of a calf heater fabric
70 parts1 - 4 layers40.1 × 38.1 mm

- 2 layers40 × 40 mm

- 2 layers53.3 × 39.7 mm

HomeAssistantSpeaker
ProrokWielki/HomeAssistantSpeaker
It is a small, 3D printable rhasspy satellite. It uses INMP441 microphone, MAX98357A audio amplifier paired with 8 Ohm 0.5 W broadband speaker, NeoPixel led strip and ESP32. It is powered from 5V USB.
33 parts15 - 2 layers134.4 × 106.7 mm

Led controller
MbFredys/PCB-LEDs-Controller
LED-controller PCB design exercise focused on PWM control, power distribution, and hardware documentation.
42 parts6 - 2 layers141 × 56.9 mm
