examples: clean up examples and add blinky1 for Arduino

Arduino has trouble supporting anything that's not extremely simple, so
add a simple blinky example for it. Also, it may be useful anyway.

Makefile

@@ -3,7 +3,7 @@
 all: tgo
 tgo: build/tgo
 
-.PHONY: all tgo run-hello run-blinky clean fmt gen-device gen-device-nrf
+.PHONY: all tgo run-test run-blinky run-blinky2 clean fmt gen-device gen-device-nrf
 
 # Custom LLVM toolchain.
 LLVM := $(shell go env GOPATH)/src/github.com/aykevl/llvm/bindings/go/llvm/workdir/llvm_build/bin/
@@ -56,11 +56,12 @@ endif
 
 
 
-run-hello: build/hello
-	./build/hello
+run-test: build/test
+	./build/test
 
-run-blinky: build/blinky
-	./build/blinky
+run-blinky: run-blinky2
+run-blinky2: build/blinky2
+	./build/blinky2
 
 ifeq ($(TARGET),pca10040)
 flash-%: build/%.hex
@@ -74,7 +75,7 @@ clean:
 	@rm -rf build
 
 fmt:
-	@go fmt . ./src/examples/hello
+	@go fmt . ./src/examples/test
 	@go fmt ./src/runtime/*.go
 
 gen-device: gen-device-nrf

README.markdown

@@ -131,7 +131,7 @@ development.
 
 After LLVM has been built, you can run an example with:
 
-    make run-hello
+    make run-test
 
 For a blinky example on the PCA10040 development board, do this:
 

src/examples/blinky1/blinky1.go

@@ -0,0 +1,20 @@
+package main
+
+// This is the most minimal blinky example and should run almost everywhere.
+
+import (
+	"machine"
+	"runtime"
+)
+
+func main() {
+	led := machine.GPIO{machine.LED}
+	led.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	for {
+		led.Low()
+		runtime.Sleep(runtime.Millisecond * 500)
+
+		led.High()
+		runtime.Sleep(runtime.Millisecond * 500)
+	}
+}

src/examples/blinky2/blinky2.go

@@ -1,5 +1,10 @@
 package main
 
+// This blinky is a bit more advanced than blink1, with two goroutines running
+// at the same time and blinking a different LED. The delay of led2 is slightly
+// less than half of led1, which would be hard to do without some sort of
+// concurrency.
+
 import (
 	"machine"
 	"runtime"

src/examples/test/test.go

@@ -1,5 +1,7 @@
 package main
 
+// This file is here to test features of the Go compiler.
+
 import "unicode"
 
 type Thing struct {