mcp3008: added package and samples for mcp3008 10-bit 8-channel adc

samples/.gitignore

@@ -24,3 +24,5 @@ universalblinker
 us020
 watersensor
 spi
+mcp3008
+spimcp3008

samples/mcp3008.go

@@ -0,0 +1,33 @@
+// +build ignore
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"time"
+
+	"github.com/kidoman/embd/convertors/mcp3008"
+)
+
+func main() {
+	flag.Parse()
+	fmt.Println("This is a sample code for mcp3008 10bit 8 channel ADC")
+
+	adc, err := mcp3008.New(mcp3008.SingleMode, 0, 1000000)
+	if err != nil {
+		panic(err)
+	}
+	defer adc.Close()
+
+	for i := 0; i < 20; i++ {
+		time.Sleep(1 * time.Second)
+		val, err := adc.AnalogValueAt(0)
+		if err != nil {
+			panic(err)
+		}
+
+		fmt.Printf("Analog value is: %v\n", val)
+	}
+
+}

samples/spimcp3008.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"time"
+
+	"github.com/kidoman/embd"
+	_ "github.com/kidoman/embd/host/all"
+)
+
+func main() {
+	flag.Parse()
+	if err := embd.InitSPI(); err != nil {
+		panic(err)
+	}
+
+	bus := embd.NewSPIBus(embd.SpiMode0, 0, 1000000, 8, 0)
+
+	defer clean(bus)
+
+	for i := 0; i < 30; i++ {
+		time.Sleep(1 * time.Second)
+		val, _ := getSensorValue(bus)
+		fmt.Printf("value is: %v\n", val)
+	}
+
+}
+
+func clean(bus embd.SPIBus) {
+	bus.Close()
+	embd.CloseSPI()
+}
+
+func getSensorValue(bus embd.SPIBus) (uint16, error) {
+	data := make([]uint8, 3)
+	data[0] = 1
+	data[1] = 128
+	data[2] = 0
+	var err error
+	err = bus.TransferAndRecieveData(data)
+	if err != nil {
+		return uint16(0), err
+	}
+	return uint16(data[1]&0x03)<<8 | uint16(data[2]), nil
+}