ravedude: Allow skipping the reset question

Add a new commandline option to skip the reset question.  This can be
useful when a self-reset function is implemented in the firmware running
on the board.

ravedude/src/main.rs

@@ -2,6 +2,9 @@ use anyhow::Context as _;
 use colored::Colorize as _;
 use structopt::clap::AppSettings;
 
+use std::time::Duration;
+use std::thread;
+
 mod avrdude;
 mod board;
 mod console;
@@ -39,6 +42,12 @@ struct Args {
     #[structopt(short = "P", long = "port", parse(from_os_str), env = "RAVEDUDE_PORT")]
     port: Option<std::path::PathBuf>,
 
+    /// This assumes the board is already resetting.
+    /// Instead of giving the reset instructions and waiting for user confirmation, we wait the amount in milliseconds before proceeding.
+    /// Set this value to 0 to skip the board reset question instantly.
+    #[structopt(short = "d", long = "reset-delay")]
+    reset_delay: Option<u64>,
+
     /// Which board to interact with.
     ///
     /// Must be one of the known board identifiers:
@@ -81,13 +90,23 @@ fn ravedude() -> anyhow::Result<()> {
 
     task_message!("Board", "{}", board.display_name());
 
-    if let Some(msg) = board.needs_reset() {
-        warning!("this board cannot reset itself.");
-        eprintln!("");
-        eprintln!("    {}", msg);
-        eprintln!("");
-        eprint!("Once reset, press ENTER here: ");
-        std::io::stdin().read_line(&mut String::new())?;
+    if let Some(wait_time) = args.reset_delay{
+        if wait_time > 0 {
+            println!("Waiting {} ms before proceeding", wait_time);
+            let wait_time = Duration::from_millis(wait_time);
+            thread::sleep(wait_time);
+        }else{
+            println!("Assuming board has been reset");
+        }
+    }else{
+        if let Some(msg) = board.needs_reset() {
+            warning!("this board cannot reset itself.");
+            eprintln!("");
+            eprintln!("    {}", msg);
+            eprintln!("");
+            eprint!("Once reset, press ENTER here: ");
+            std::io::stdin().read_line(&mut String::new())?;
+        }
     }
 
     let port = match args.port {