Blobfi

Blobfi

A custom PCB-based Tamagotchi virtual pet called Blobfi

About the project

A custom PCB-based Tamagotchi-like virtual pet built the XIAO-ESP32-C6 MCU, featuring a 0.96" OLED display, 500mah battery with USB-C charging (via the esp32), 3 buttons, a temperature sensor and a vibration motor.

I made this project to have my own custom tamagotchi pet called Blobfi, which is a blobfish, because I love blobfishes!!

I used Tanishq's tamagotchi as insiration & reference.

How to build your own Blobfi

To build this project yourself, first you need to 3d print the top and bottom parts (link to the folder with 3d models), also you preferably should print 4 of the screen supports that will be used to mount hold the screen parallel to the PCB. Then you need to buy all the parts and the PCB and then assemple it all together as shown on the picture below (also you need to screw the PCB and the top to the bottom enclosure in using 3 M3x8mm screws each):

And then you need to flash the ESP32 using my blobfi_firmware sketch in Arduino IDE, also you need to install Adafruit SSD1306, OneWireNg, DallasTemperature libraries with their dependencies.

Tools I used

For PCB & schematic design I used KiCAD, for 3D design I used Autodesk Fusion (free version), for coding the firmware I used Arduino IDE, for testing the firmware I used Wowki hardware simulator and for general design (Edge.Cuts & the Zine) I used Figma

PCB design

Schematic

3D model

Firmware

Blobfi has 3 stats which decrease by 1 each 5 minutes:

• Hunger
• Happiness
• Energy

And if the temperature of Blobfi goes above 40C or below 5C happiness will decrease at 2x rate.

Depending on these stats you will have a different image of a blobfish on your main screen, here is an example of a happy Blobfi:

Emulated render:

An actual photo:

If any of the stats will go below 0 it will be set to 0 and the vibration motor will shake your Blobfi as it wants to eat/sleep/play.

Also if any stat is below 10 then the bar will blink on the screen.

Actions buttons do:

• Left button: Feed Blobfi, +15 hunger and +5 energy
• Middle button: Play with Blobfi, +15 happiness and -5 energy
• Right button: Put Blobfi to sleep, +15 energy
• Left and right buttons at the same time: Put the device into deep sleep (basically turning it off, you can wake it up by pressing any button)

And here is an example of an action animation (duration - 3s):

Deep sleep

Also my firmware uses ESP32 deep sleep feature, which allows it to go into a very low power use mode. After 30 seconds of inactivity (not pressing any buttons) the device will go into deep sleep.

When the device goes into deep sleep it will disable the display, but it will start an internal timer for the next update of Blobfi (5 minutes minus the time from the last update that had already passed) and it will still listen to any button inputs, and if you press any button it will wake up to the normal state.

This allows to reduce ESP32C6 and display's total current from about 50mA to about 17µA which is around 2941 times less current. This allows for the device to actually work for longer than some 10-15 hours, now it can do multiple weeks (theoretically months, has not tested that in practice yet).

BOM

The display is out of stock so the price is for buying one from "Other suppliers" on LCSC

Build photos

For reference the squares are 5x5mm

demo

My zine for this project