Driver for ADXL345 3-axis digital accelerometer (#33)

* Driver for ADXL345 3-axis digital accelerometer

examples/adxl345/main.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"github.com/tinygo-org/drivers/adxl345"
+)
+
+func main() {
+	machine.I2C0.Configure(machine.I2CConfig{})
+	sensor := adxl345.New(machine.I2C0)
+	sensor.Configure()
+
+	println("ADXL345 starts")
+	for {
+		sensor.Update()
+		x, y, z := sensor.Acceleration()
+		println("X:", x, "Y:", y, "Z:", z)
+
+		rx, ry, rz := sensor.RawXYZ()
+		println("X (raw):", rx, "Y (raw):", ry, "Z (raw):", rz)
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}