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package main
import (
"golang.org/x/exp/io/spi"
"log"
)
type RealUnicorn struct {
BaseUnicorn
device *spi.Device
}
// NewReal ...
// Constructs a new real unicorn from fairy dust and sprinkles
func NewReal() (*RealUnicorn, error) {
dev, err := spi.Open(&spi.Devfs{
Dev: "/dev/spidev0.0",
Mode: spi.Mode0,
MaxSpeed: 9000000,
})
if err != nil {
return nil, err
}
return &RealUnicorn{
BaseUnicorn{
pixels: makePixels(16, 16),
},
dev,
}, nil
}
func (u *RealUnicorn) Show() {
// Width * height * colours + leading bit
width := u.GetWidth()
height := u.GetHeight()
write := make([]byte, (width*height*3)+1)
// Add the leading bit
write[0] = 0x72
// Add all the pixel values
ix := 1
for x := uint8(0); x < width; x++ {
for y := uint8(0); y < height; y++ {
for j := 0; j < 3; j++ {
write[ix] = u.pixels[x][y][j]
ix++
}
}
}
// Write to the device
err := u.device.Tx(write, nil)
if err != nil {
log.Printf("Error writing to SPI device %v", err)
}
}
func (u *RealUnicorn) Off() {
u.Close()
}
func (u *RealUnicorn) Close() error {
return u.device.Close()
}
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