diff --git a/convertors/mcp3008/mcp3008.go b/convertors/mcp3008/mcp3008.go
index f074a4e..7636e29 100644
--- a/convertors/mcp3008/mcp3008.go
+++ b/convertors/mcp3008/mcp3008.go
@@ -16,35 +16,20 @@ type mcp3008 struct {
 var SingleMode byte = 1
 var DifferenceMode byte = 0
 
-func New(mode byte, spiChan, speed int) (*mcp3008, error) {
-	if err := embd.InitSPI(); err != nil {
-		return nil, err
-	}
-	glog.V(3).Infof("mcp3008: getting spiBus with mode: %v, channel: %v, speed: %v", mode, spiChan, speed)
-	spiBus := embd.NewSPIBus(embd.SpiMode0, byte(spiChan), speed, 0, 0)
-	return &mcp3008{mode, spiBus}, nil
+func New(mode byte, bus embd.SPIBus) *mcp3008 {
+	return &mcp3008{mode, bus}
 }
 
 func (m *mcp3008) AnalogValueAt(chanNum int) (int, error) {
-	var data [3]uint8
+	data := make([]uint8, 3)
 	data[0] = 1
 	data[1] = uint8(m.mode)<<7 | uint8(chanNum)<<4
 	data[2] = 0
 
+	glog.V(2).Infof("mcp3008: sendingdata buffer %v", data)
 	if err := m.bus.TransferAndRecieveData(data); err != nil {
 		return 0, err
 	}
 
 	return int(uint16(data[1]&0x03)<<8 | uint16(data[2])), nil
 }
-
-func (m *mcp3008) Close() error {
-	glog.V(2).Infoln("mcp3008: performing cleanup")
-	if err := m.bus.Close(); err != nil {
-		return err
-	}
-	if err := embd.CloseSPI(); err != nil {
-		return err
-	}
-	return nil
-}
diff --git a/samples/mcp3008.go b/samples/mcp3008.go
index 252f2d1..ff2f09f 100644
--- a/samples/mcp3008.go
+++ b/samples/mcp3008.go
@@ -8,17 +8,23 @@ import (
 	"time"
 
 	"github.com/kidoman/embd/convertors/mcp3008"
+
+	"github.com/kidoman/embd"
 )
 
 func main() {
 	flag.Parse()
-	fmt.Println("This is a sample code for mcp3008 10bit 8 channel ADC")
+	fmt.Println("this is a sample code for mcp3008 10bit 8 channel ADC")
 
-	adc, err := mcp3008.New(mcp3008.SingleMode, 0, 1000000)
-	if err != nil {
+	if err := embd.InitSPI(); err != nil {
 		panic(err)
 	}
-	defer adc.Close()
+	defer embd.CloseSPI()
+
+	spiBus := embd.NewSPIBus(embd.SpiMode0, 0, 1000000, 8, 0)
+	defer spiBus.Close()
+
+	adc := mcp3008.New(mcp3008.SingleMode, spiBus)
 
 	for i := 0; i < 20; i++ {
 		time.Sleep(1 * time.Second)
@@ -27,7 +33,7 @@ func main() {
 			panic(err)
 		}
 
-		fmt.Printf("Analog value is: %v\n", val)
+		fmt.Printf("analog value is: %v\n", val)
 	}
 
 }