Merge pull request #143 from jamez70/bmp180_test

bmp180_read will do continuous reads on the bmp180 pressure sensor fo…

test/bmp180_read.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"fmt"
+	"github.com/kidoman/embd"
+	_ "github.com/kidoman/embd/host/all"
+	"github.com/kidoman/embd/sensor/bmp180"
+)
+
+
+var i2cbus embd.I2CBus
+var myBMP180 *bmp180.BMP180
+
+func readBMP180() (float64, float64, error) { // ºCelsius, Meters
+	temp, err := myBMP180.Temperature()
+	if err != nil {
+		return temp, 0.0, err
+	}
+	altitude, err := myBMP180.Altitude()
+	altitude = float64(1/0.3048) * altitude // Convert meters to feet.
+	if err != nil {
+		return temp, altitude, err
+	}
+	return temp, altitude, nil
+}
+
+
+func initBMP180() error {
+	myBMP180 = bmp180.New(i2cbus) //TODO: error checking.
+	return nil
+}
+
+func initI2C() error {
+	i2cbus = embd.NewI2CBus(1) //TODO: error checking.
+	return nil
+}
+
+// Unused at the moment. 5 second update, since read functions in bmp180 are slow.
+func tempAndPressureReader() {
+	// Read temperature and pressure altitude.
+	temp, alt, err_bmp180 := readBMP180()
+	// Process.
+	if err_bmp180 != nil {
+		fmt.Printf("readBMP180(): %s\n", err_bmp180.Error())
+	} else {
+		fmt.Printf("Temp %f Alt %f\n",temp,alt)
+	}
+}
+
+
+
+func initAHRS() error {
+	if err := initI2C(); err != nil { // I2C bus.
+		return err
+	}
+	if err := initBMP180(); err != nil { // I2C temperature and pressure altitude.
+		i2cbus.Close()
+		return err
+	}
+	go tempAndPressureReader()
+
+	return nil
+}
+
+
+func main() {
+	fmt.Printf("Hello world!\n")
+	initAHRS()
+	for {
+		tempAndPressureReader()
+	}
+}