add Sandbox Electronics NDIR CO2 sensor driver (2) (#580)

add sandbox electronics NDIR CO2 sensor

examples/ndir/main_ndir.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/ndir"
+)
+
+var (
+	ndirBus = machine.I2C0
+)
+
+func main() {
+	err := ndirBus.Configure(machine.I2CConfig{
+		Frequency: 100_000,
+	})
+	if err != nil {
+		panic("i2c config fail:" + err.Error())
+	}
+	// Set the address based on how the resistors are soldered.
+	// True means the left and middle pads are joined.
+	ndirAddr := ndir.Addr(true, false)
+	dev := ndir.NewDevI2C(ndirBus, ndirAddr)
+	err = dev.Init()
+	if err != nil {
+		panic("ndir init fail:" + err.Error())
+	}
+	// Datasheet tells us to wait 12 seconds before reading from the sensor.
+	time.Sleep(12 * time.Second)
+	for {
+		time.Sleep(time.Second)
+		err := dev.Update(drivers.AllMeasurements)
+		if err != nil {
+			println(err.Error())
+			continue
+		}
+		println("PPM:", dev.PPMCO2())
+	}
+}