WIP first draft of terraforming script

boot.go

@@ -0,0 +1,67 @@
+// =============================================================================
+// Auth: Alex Celani
+// File: boot.go
+// Revn: 10-10-2023  1.0
+// Func: Blink a light when the pi boots (or on login, but who cares)
+//
+// TODO: create
+// =============================================================================
+// CHANGE LOG
+// -----------------------------------------------------------------------------
+// 06-23-2022: init
+// 10-10-2023: imported flag
+//             added flag to define gpio pin at runtime
+//
+// =============================================================================
+
+package main
+
+
+import (
+    "flag"      // IntVar, Parse
+    "fmt"       // Println
+    // rpio.Pin, Pin, Open, Close, Output, Toggle
+    "github.com/stianeikeland/go-rpio"
+    "os"        // Exit
+    "time"      // Sleep, time.Second
+)
+
+
+/*
+Toggles a LED on physical pin 19 (mcu pin 10)
+Connect a LED with resistor from pin 19 to ground.
+*/
+
+
+var pin rpio.Pin    // global pin object
+var num int         // flag variable, holds pin number
+
+
+func main() {
+
+    // map input flag to variable
+    flag.IntVar( &num, "p", 10, "pin number" )
+    flag.Parse()
+
+    // create pin object at given pin number
+    pin = rpio.Pin( num )
+    // Open and map memory to access gpio, check for errors
+    if err := rpio.Open(); err != nil {
+        fmt.Println( "Fatal: pin open failed" )
+        fmt.Println( "Error: ", err.Error() )
+        os.Exit(1)
+    }
+
+    // Unmap gpio memory when done
+    defer rpio.Close()
+
+    // Set pin to output mode
+    pin.Output()
+
+    // Toggle pin 2 times
+    for i := 0; i < 4; i++ {
+        pin.Toggle()
+        time.Sleep(time.Second / 10)
+    }
+}
+