Fix incorrect usage. a 'pin number' was passed to port.Connect(), when that parameter is actually the bit count.

inky/impression.go

@@ -160,7 +160,7 @@ func NewImpression(p spi.Port, dc gpio.PinOut, reset gpio.PinOut, busy gpio.PinI
 	// is 192K Bytes. To make the Impression 7.3 treat this as single trans-
 	// action, we have to take over control of the CS pin and manipulate it
 	// as required.
-	c, err := p.Connect(cSpeed, spi.Mode0|spi.NoCS, cs0Pin)
+	c, err := p.Connect(cSpeed, spi.Mode0|spi.NoCS, 8)
 	if err != nil {
 		return nil, fmt.Errorf("failed to connect to inky over spi: %v", err)
 	}
@@ -191,7 +191,7 @@ func NewImpression(p spi.Port, dc gpio.PinOut, reset gpio.PinOut, busy gpio.PinI
 			model:      o.Model,
 			variant:    o.DisplayVariant,
 			pcbVariant: o.PCBVariant,
-			cs:         gpioreg.ByName("GPIO8"),
+			cs:         gpioreg.ByName(cs0Pin),
 		},
 		saturation: 50, // Looks good enough for most of the images.
 	}

inky/inky.go

@@ -23,7 +23,7 @@ var _ display.Drawer = &Dev{}
 var _ conn.Resource = &Dev{}
 
 const (
-	cs0Pin = 8
+	cs0Pin = "GPIO8"
 )
 
 var borderColor = map[Color]byte{
@@ -75,7 +75,7 @@ func New(p spi.Port, dc gpio.PinOut, reset gpio.PinOut, busy gpio.PinIn, o *Opts
 		return nil, fmt.Errorf("unsupported color: %v", o.ModelColor)
 	}
 
-	c, err := p.Connect(488*physic.KiloHertz, spi.Mode0, cs0Pin)
+	c, err := p.Connect(488*physic.KiloHertz, spi.Mode0 | spi.NoCS, 8)
 	if err != nil {
 		return nil, fmt.Errorf("failed to connect to inky over spi: %v", err)
 	}
@@ -101,7 +101,7 @@ func New(p spi.Port, dc gpio.PinOut, reset gpio.PinOut, busy gpio.PinIn, o *Opts
 		model:      o.Model,
 		variant:    o.DisplayVariant,
 		pcbVariant: o.PCBVariant,
-		cs:         gpioreg.ByName("GPIO8"),
+		cs:         gpioreg.ByName(cs0Pin),
 	}
 
 	switch o.Model {