Minor change in edge event detection api

Also other minor changes and gofmt

examples/event/event.go

@@ -2,7 +2,7 @@
 
 An example of edge event handling by @Drahoslav7, using the go-rpio library
 
-Waits for button to be pressed before exit.
+Waits for button to be pressed twice before exit.
 
 Connect a button between pin 22 and some GND pin.
 
@@ -12,8 +12,9 @@ package main
 
 import (
 	"fmt"
-	"time"
 	"os"
+	"time"
+
 	"github.com/stianeikeland/go-rpio"
 )
 
@@ -37,12 +38,12 @@ func main() {
 
 	fmt.Println("press a button")
 
-	for {
+	for i := 0; i < 2; {
 		if pin.EdgeDetected() { // check if event occured
-			fmt.Println("button pressed less than a second ago")
-			break
+			fmt.Println("button pressed")
+			i++
 		}
-		time.Sleep(time.Second)
+		time.Sleep(time.Second / 2)
 	}
 	pin.Detect(rpio.NoEdge) // disable edge event detection
 }

rpio.go

@@ -327,28 +327,33 @@ func TogglePin(pin Pin) {
 //
 // It also clears previously detected event of this pin if any.
 //
-// Note that call with RiseEdge followed by call with FallEdge has the same effect as call with AnyEdge,
-// to disable previously enabled event call it with NoEdge.
+// Note that call with RiseEdge will disable previously set FallEdge detection and vice versa
+// You have to call with AnyEdge, to enable detection for both edges
+// To disable previously enabled detection call it with NoEdge
 func DetectEdge(pin Pin, edge Edge) {
 	p := uint8(pin)
 
 	// Rising edge detect enable register (19/20 depending on bank)
 	// Falling edge detect enable register (22/23 depending on bank)
+	// Event detect status register (16/17)
 	renReg := p/32 + 19
 	fenReg := p/32 + 22
+	edsReg := p/32 + 16
+
+	bit := uint32(1 << (p & 31))
 
-	if edge == NoEdge { // clear bits
-		gpioMem[renReg] = gpioMem[renReg] &^ (1 << (p&31))
-		gpioMem[fenReg] = gpioMem[fenReg] &^ (1 << (p&31))
-	}
 	if edge&RiseEdge > 0 { // set bit
-		gpioMem[renReg] = gpioMem[renReg] | (1 << (p&31))
+		gpioMem[renReg] = gpioMem[renReg] | bit
+	} else { // clear bit
+		gpioMem[renReg] = gpioMem[renReg] &^ bit
 	}
 	if edge&FallEdge > 0 { // set bit
-		gpioMem[fenReg] = gpioMem[fenReg] | (1 << (p&31))
+		gpioMem[fenReg] = gpioMem[fenReg] | bit
+	} else { // clear bit
+		gpioMem[fenReg] = gpioMem[fenReg] &^ bit
 	}
 
-	EdgeDetected(pin) // to clear outdated detection
+	gpioMem[edsReg] = bit // to clear outdated detection
 }
 
 // Check whether edge event occured

rpio_test.go

@@ -1,20 +1,21 @@
 package rpio
 
 import (
+	"os"
 	"testing"
 	"time"
-	"os"
 )
 
 func TestMain(m *testing.M) {
+	println("Note: bcm pins 2 and 3 has to be directly connected")
 	if err := Open(); err != nil {
 		panic(err)
 	}
+	defer Close()
 	os.Exit(m.Run())
 }
 
 func TestRisingEdgeEvent(t *testing.T) {
-	// bcm pins 2 and 3 has to be directly connected
 	src := Pin(3)
 	src.Mode(Output)
 	src.Low()
@@ -25,14 +26,15 @@ func TestRisingEdgeEvent(t *testing.T) {
 	pin.Detect(RiseEdge)
 
 	timeout := time.After(time.Second)
-	loop: for {
+loop:
+	for {
 		src.High()
 
 		time.Sleep(time.Second / 5)
 		if pin.EdgeDetected() {
 			t.Log("edge rised")
 		} else {
-			t.Errorf("Raise event should be detected")
+			t.Errorf("Rise event should be detected")
 		}
 		select {
 		case <-timeout:
@@ -48,12 +50,11 @@ func TestRisingEdgeEvent(t *testing.T) {
 	pin.Detect(NoEdge)
 	src.High()
 	if pin.EdgeDetected() {
-		t.Error("Fall should not be detected, events disabled")
+		t.Error("Rise should not be detected, events disabled")
 	}
 }
 
 func TestFallingEdgeEvent(t *testing.T) {
-	// bcm pins 2 and 3 has to be directly connected
 	src := Pin(3)
 	src.Mode(Output)
 	src.High()
@@ -64,7 +65,8 @@ func TestFallingEdgeEvent(t *testing.T) {
 	pin.Detect(FallEdge)
 
 	timeout := time.After(time.Second)
-	loop: for {
+loop:
+	for {
 		src.Low()
 
 		time.Sleep(time.Second / 5)