pcf8523: RTC driver

examples/pcf8523/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"machine"
+	"time"
+	"tinygo.org/x/drivers/pcf8523"
+)
+
+func main() {
+	machine.I2C0.Configure(machine.I2CConfig{})
+	dev := pcf8523.New(machine.I2C0)
+
+	// make sure the battery takes over if power is lost
+	err := dev.SetPowerManagement(pcf8523.PowerManagement_SwitchOver_ModeStandard)
+	if err != nil {
+		panic(err)
+	}
+
+	// set RTC once, i.e. from `date -u +"%Y-%m-%dT%H:%M:%SZ"`
+	now, _ := time.Parse(time.RFC3339, "2023-09-18T20:31:38Z")
+	err = dev.SetTime(now)
+	if err != nil {
+		panic(err)
+	}
+
+	for {
+		ts, err := dev.ReadTime()
+		if err != nil {
+			panic(err)
+		}
+		println("tick-tock, it's: " + ts.String())
+		time.Sleep(2 * time.Second)
+	}
+}