Add support for ams AS560x on-axis magnetic rotary position sensors

examples/as560x/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"machine"
+	"machine/usb/hid/mouse"
+	"math"
+	"time"
+
+	"tinygo.org/x/drivers/as560x"
+)
+
+func main() {
+	// Let's use the AS5600 to make the world's most useless mouse with just a single X-axis & no buttons (!)
+	machine.I2C0.Configure(machine.I2CConfig{
+		Frequency: machine.TWI_FREQ_400KHZ,
+		SDA:       machine.GPIO4,
+		SCL:       machine.GPIO5,
+	})
+	as5600 := as560x.NewAS5600(machine.I2C0)
+	as5600.Configure(as560x.Config{})
+	mouse := mouse.New()
+
+	lastAngle := -1
+	for {
+		time.Sleep(time.Millisecond * 10)
+		// Get the magnet status of the AS5600
+		magnetDetected, magnetStrength, err := as5600.MagnetStatus()
+		if err != nil {
+			continue
+		}
+		// Get the raw angle from the AS5600
+		angle, _, err := as5600.RawAngle(as560x.ANGLE_NATIVE)
+		if err != nil {
+			continue
+		}
+		str := ""
+		if !magnetDetected {
+			str += "NOT "
+		}
+		str += "detected. Strength is "
+		switch magnetStrength {
+		case as560x.MagnetTooWeak:
+			str += "too weak"
+		case as560x.MagnetTooStrong:
+			str += "too strong"
+		default:
+			str += "ok"
+		}
+		println("Raw angle:", angle, "Magnet was", str)
+		if lastAngle != -1 {
+			diff := int(angle) - lastAngle
+			// correct the zero crossover glitch
+			if diff < -0xc00 {
+				diff += 0xfff
+			} else if diff > 0xc00 {
+				diff -= 0xfff
+			}
+			// debounce the noise (could use the sensor's filters/hysteresis instead?)
+			if math.Abs(float64(diff)) > 2 {
+				// move the mouse x-axis in response to the AS5600
+				mouse.Move(diff, 0)
+			}
+		}
+		lastAngle = int(angle)
+	}
+}