Use rust serial crate for reading from serial

Incomplete - can successfully initiate contact w/ radio but can't read
data

Cargo.toml

@@ -13,6 +13,7 @@ crate-type = ["staticlib"]
 libc = "0.2"
 getopts = "0.2"
 chrono = "0.4"
+serial = "0.4"
 
 [build-dependencies]
 bindgen = "0.53.1"

src/radio.rs

@@ -44,8 +44,6 @@ extern {
   fn hid_init(vid: c_int, pid: c_int) -> c_int;
   fn hid_identify() -> *const c_char;
   fn hid_close();
-
-  fn serial_close();
 }
 
 
@@ -127,7 +125,7 @@ pub fn disconnect() {
     dfu_reboot();
     dfu_close();
     hid_close();
-    serial_close();
+    crate::serial::close();
   }
 }
 

src/serial.rs

@@ -1,9 +1,12 @@
-use std::ffi::{CStr, CString};
+use std::ffi::{CStr};
 use libc::{c_char};
+use std::process::exit;
+use std::time::Duration;
 
 extern {
   fn find_path(vid: libc::c_int, pid: libc::c_int) -> *const c_char;
   fn serial_identify(s: *const c_char) -> *const c_char;
+  fn serial_close();
 }
 
 /// Connect to the specified device.
@@ -23,17 +26,86 @@ pub fn serial_init(vid: u32, pid: u32, trace_flag: bool) -> Option<String> {
     Some(dev_path)
 }
 
+fn send_receive(port: &mut dyn serial::SerialPort, command: &[u8], reply_len: usize, trace: bool) -> Vec<u8> {
+  if trace {
+    eprintln!("----Send [{}] {:?}", command.len(), command);
+  }
+
+  match port.write(&command) {
+    Ok(n) => {
+      if trace {
+        eprintln!("Wrote {} bytes over serial", n);
+      }
+    },
+    Err(e) => {
+      eprintln!("Serial write error: {}", e);
+      exit(-1);
+    }
+  };
+
+  let mut buf: Vec<u8> = vec![0; reply_len];
+  match port.read(&mut buf) {
+    Ok(n) if n == reply_len => {
+      if trace {
+        eprintln!("----Received [{}] {:?}", reply_len, buf);
+      }
+    },
+    Ok(n) => {
+      eprintln!("Serial: read {} bytes, expected {}", n, reply_len);
+    }
+    Err(e) => {
+      eprintln!("Serial read error: {}", e);
+      exit(-1);
+    }
+  };
+  buf
+}
+
 /// Query and return the device identification string.
 /// On error, return None.
 pub fn identify(dev_path: &str) -> Option<String> {
-  let dev_path_c = CString::new(dev_path).unwrap();
-  let ptr = dev_path_c.as_ptr() as *mut c_char;
+  use serial::prelude::*;
+
+  let mut port = match serial::open(dev_path) {
+    Ok(port) => port,
+    Err(err) => {
+      println!("{}", err);
+      exit(-1);
+    }
+  };
+
+  port.reconfigure(&|settings: &mut dyn SerialPortSettings| {
+    settings.set_baud_rate(serial::BaudRate::Baud115200)?;
+    settings.set_char_size(serial::CharSize::Bits8);
+    Ok(())
+  }).unwrap();
+  port.set_timeout(Duration::new(1,0)).unwrap();
+
+  let program_cmd = b"PROGRAM";
+  let program_cmd_2 = b"\x02";
+
+  let program_ack = b"QX\x06";
+  let command_ack: u8 = b'\x06';
+
+  let output = send_receive(&mut port, program_cmd, 3, true);
+  if output != program_ack {
+    eprintln!("serial identify: wrong PRG acknowledge {:?}, expected {:?}", output, program_ack);
+  }
+
+  // Expected output should be something like:
+  // 49 44 38 36 38 55 56 45 00 56 31 30 32 00 00 06
+  //  I  D  8  6  8  U  V  E     V  1  0  2
+  let output = send_receive(&mut port, program_cmd_2, 16, true);
+  if (output[0] != 'I' as u8) || (output[15] != command_ack) {
+    eprintln!("serial identify: wrong PRG2 reply {:?} expected 'I'...'\\6'", output);
+  }
+
+  return Some(String::from_utf8(output[1..7].to_vec()).unwrap())
+}
+
+/// Close the serial port.
+pub fn close() {
   unsafe {
-    let output = serial_identify(ptr);
-    if output.is_null() {
-      None
-    } else {
-      Some(CStr::from_ptr(output).to_str().unwrap().to_string())
-    }
+    serial_close();
   }
 }