This device I'm building is not very beginner-friendly. It uses all SMD components, a bare displays screen, needs you to flash the bootloader to a bare chip and compile your own CircuitPython, etc. Quite a bit of work, to be honest. On the other hand, I would like the software library I'm making for this to be generally useful, and not just limited to this one device. So I wrote it in a way that lets you use it with pretty much any SPI display with 16-bit colors, and any buttons. Today I went and made a "homebrew" version of µGame, to show that it really doesn't have to be hard.
My initial experiments used a Trinket M0, but to really write an interesting game you will probably need much more room, so this time I used a Feather M0 Express, which has an additional flash chip. I also used a breakout board I made for displays, and a bunch of buttons:
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I had to bend the legs of those buttons a little bit, to pack them on the board tightly enough:
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A little bit of soldering:
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And we have out gamepad:
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Next, we need to wire the display module. I used a module with the same ST7735R display as I used on the µGame, so that I can use the same code, but you can also use SSD1331, SSD1351, HX8353 or ILI9341.
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I wired it to the SPI pins of the feather, with CS pulled low permanently, RST connected to feather's reset, and LED pulled up.
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Then I also wired the buttons — one side of each button goes to GND, and the other side to one of the digital pins.
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And that's it. Add some pin headers, and plug it into the feather:
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Next, I had to compile CircuitPython with my library enabled, and provide custom initialization code:
import board
import digitalio
import busio
import st7735r
import gamepad
K_X = 0x01
K_DOWN = 0x02
K_LEFT = 0x04
K_RIGHT = 0x08
K_UP = 0x10
K_O = 0x20
dc = digitalio.DigitalInOut(board.MISO)
spi = busio.SPI(clock=board.SCK, MOSI=board.MOSI)
spi.try_lock()
spi.configure(baudrate=23000000, polarity=0, phase=0)
display = st7735r.ST7735R(spi, dc, 0b110)
buttons = gamepad.GamePad(
digitalio.DigitalInOut(board.D6),
digitalio.DigitalInOut(board.D11),
digitalio.DigitalInOut(board.D12),
digitalio.DigitalInOut(board.D9),
digitalio.DigitalInOut(board.D10),
digitalio.DigitalInOut(board.D5),
)
(Since that module doesn't use the MISO pin, I used it for D/C). I uploaded my work-in-progress demo game, and voila, it works!
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UPDATE: I had to make two changes compared to these photos. One, I forgot a wire from the fire buttons to the GND, and two, I now connected the CS pin to D13, instead of directly to GND.
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