Put a Face to a Robot

Published on 2022-07-29 in Fluffbug.

Everything is better with eyes. Putting goggly eyes on things makes them instantly relatable and cute or creepy. We simply can’t remain emotionally neutral to something that looks at us. So I decided that the robots need faces.

Of course I could have used one of the many Wemos D1 shields available on the market to add an OLED screen, a TFT screen or even just a LED matrix, but where is the fun in that? I recently got a new round screen to work, so I decided to make a shield for it, and to design it so it works well with those robots.

The back side has a lot of free space for a silkscreen, so what should I put behind a face? Of course!

This way I can use the spare PCBs without a display to decorate other robots. That was a week ago, now the PCBs have arrived, so I got it all assembled and working:

My work here is done. Here is the code I used:

import board
import displayio
import busio


_INIT = (
    b"\xFE\x00"  # Inter Register Enable 1
    b"\xEF\x00"  # Inter Register Enable 2
    b"\xB6\x02\x00\x00"  # DFC S1>S360 source G1>G32 gate
    b'\x36\x01\x48'  # MADCTL
    b'\x3a\x01\x05'  # COLMOD
    b"\xC3\x01\x13"  # PWRCTL2 VREG1A=5.06 VREG1B=0.68
    b"\xC4\x01\x13"  # PWRCTL3 VREG2A=-3.7 VREG2B=0.68
    b"\xC9\x01\x22"  # PWRCTL4
    b"\x66\x0a\x3c\x00\xcd\x67\x45\x45\x10\x00\x00\x00"
    b"\x67\x0a\x00\x3c\x00\x00\x00\x01\x54\x10\x32\x98"
    b"\x74\x07\x10\x85\x80\x00\x00\x4e\x00"
    b"\x98\x02\x3e\x07"
    b'\x21\x00'  # INVON
    b'\x11\x80\x78'  # SLEEPOUT
    b'\x29\x80\x14'  # DISPLAYON
)
displayio.release_displays()
spi = busio.SPI(clock=board.IO7, MOSI=board.IO11)
bus = displayio.FourWire(spi, chip_select=board.IO12, baudrate=40_000_000,
        reset=board.IO5, command=board.IO9)
display = displayio.Display(bus, _INIT, width=240, height=240)
display.root_group.scale = 6
display.root_group[1].x = 0
display.root_group[1].y = 0
print("\x1b[2J")
print(" O w O")

I might come up with something more complex later…