lsm303agr (#162)

* lsm303agr: add support for lsm303agr digital compass

examples/lsm303agr/main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"machine"
+	"time"
+	"tinygo.org/x/drivers/lsm303agr"
+)
+
+func main() {
+
+	machine.I2C0.Configure(machine.I2CConfig{})
+	accel_mag := lsm303agr.New(machine.I2C0)
+
+	if !accel_mag.Connected() {
+		println("LSM303AGR/MAG not connected!")
+		return
+	}
+
+	accel_mag.Configure(lsm303agr.Configuration{}) //default settings
+
+	for {
+
+		accel_x, accel_y, accel_z := accel_mag.ReadAcceleration()
+		pitch, roll := accel_mag.ReadPitchRoll()
+		mag_x, mag_y, mag_z := accel_mag.ReadMagneticField()
+		heading := accel_mag.ReadCompass()
+		temp, _ := accel_mag.ReadTemperature()
+
+		println("ACCEL_X:", accel_x, " ACCEL_Y:", accel_y, " ACCEL_Z:", accel_z)
+		println("MAG_X:", mag_x, " MAG_Y:", mag_y, " MAG_Z:", mag_z)
+		println("Pitch:", pitch, " Roll:", roll)
+		println("Heading:", heading)
+		println("Temperature:", temp/1000)
+		println("\n")
+
+		time.Sleep(time.Millisecond * 100)
+	}
+
+}