Set frequency.

src/main.rs

@@ -22,10 +22,15 @@ struct Cli {
     com: Option<String>,
 
     /// Format
-    #[arg(short = 'f', long, default_value = "result.csv")]
+    #[arg(short = 'o', long, default_value = "result.csv")]
     file: Option<String>,
+
+    /// Frequency
+    #[arg(short = 'f', long)]
+    freq: Option<u32>,
 }
 
+// Read S-meter
 fn get_smeter(comport: &str) -> String {
     let mut port = serialport::new(comport, 4800)
         .data_bits(DataBits::Eight)
@@ -71,6 +76,41 @@ fn get_smeter(comport: &str) -> String {
     }
 }
 
+// Set frequency
+fn set_freq(comport: &str, freq: u32) -> String {
+    let mut port = serialport::new(comport, 4800)
+        .data_bits(DataBits::Eight)
+        .stop_bits(StopBits::Two)
+        .parity(Parity::None)
+        .timeout(Duration::from_millis(100))
+        .open()
+        .expect("Failed to open port");
+
+    // Duh, you need the ";" on the end!
+    //let output = "FA14075000;"; // set VFO A frequency
+    let output = format!("FA{};", freq);
+    //println!("{output}");
+
+    match port.write(output.as_bytes()) {
+        Ok(_) => {
+            std::io::stdout().flush().unwrap();
+        }
+        Err(ref e) if e.kind() == ErrorKind::TimedOut => (),
+        Err(e) => eprintln!("{:?}", e)
+    }
+
+    let mut buf = [0u8; 1024];
+        match port.read(&mut buf) {
+            Ok(_) => {
+                return format!("Frequency set.");
+            }
+            Err(_) => {
+                return format!("Failed to set frequency.");
+            }
+        
+    }
+}
+
 // Write row to a file
 fn write_row(str_arr: [String; 4], file: &String, fmt: &str) -> Result<(), Box<dyn Error>> {
     // From https://docs.rs/csv/latest/csv/tutorial/index.html#writing-csv
@@ -99,6 +139,7 @@ fn write_row(str_arr: [String; 4], file: &String, fmt: &str) -> Result<(), Box<d
     }
 }
 
+// Main funtion
 fn main() {
     // Arguments
     let cli = Cli::parse();
@@ -124,6 +165,16 @@ fn main() {
         } //todo!()
     };
 
+    let frequency = match cli.freq {
+        Some(frequency) => frequency,
+        None => {
+            return;
+        } //todo!()
+    };
+
+    // Set the requested frequency
+    set_freq(&com, frequency);
+
     // Simple test loop to make sure we are getting values each time
     for _i in 1..11 {
         let s_val = get_smeter(&com);