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make serial read/write non-blocking

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This commit is contained in:
Vladan Popovic 2022-11-29 15:19:42 +01:00
parent b6e7e64e72
commit 018af71262
2 changed files with 96 additions and 122 deletions
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84
src/modem.rs
View file

@ -7,7 +7,7 @@ use std::{
error::Error,
io::{Read, Write},
thread,
time::{Duration, Instant},
time::Duration,
sync::mpsc::Receiver,
};
@ -90,31 +90,52 @@ impl<UART: serial::Uart> Modem<UART> {
/// None, then the first line is returned. If a timeout is reached. The timeout is provided on
/// input via the `timeout` argument. The first argument `contains` is checked against every
/// line in the response.
fn read_response(&mut self, contains: Option<String>, timeout: Duration) -> Result<String> {
fn command_read_response(&mut self) -> Result<String> {
let mut response = String::new();
let start = Instant::now();
let match_text: String = contains.unwrap_or("\n".to_string());
loop {
let timeout = timeout.saturating_sub(start.elapsed());
let line = self.serial.read_line(timeout).map_err(|_| ModemError::ReadError)?;
print!("Read {} bytes from serial: {}", line.len(), line);
response.push_str(&line);
if line.contains("ERROR") || line.contains(&match_text) {
println!("Found match {} for line {} ; exiting response reader now ...", match_text, line);
println!("-----------------------------------------------------------");
break Ok(response.to_string())
let mut buf = vec![0; 1024];
let num_bytes = self.serial
.read(buf.as_mut_slice())
.map_err(|_| ModemError::ReadError)?;
response.push_str(std::str::from_utf8(&buf[0..num_bytes]).map_err(|_| ModemError::ReadError)?);
if num_bytes < buf.len() {
break
}
}
print!("Read {} bytes from serial: {}", response.len(), response);
Ok(response)
}
fn send_command(&mut self, cmd: Command) -> Result<String> {
println!("-----------------------------------------------------------");
println!("Sending {} ...", cmd.text);
println!("Sending to TX ({}) ...", cmd.text);
let _ = self.serial
.send_bytes(cmd.text.as_bytes(), Some('\r' as u8))
.map_err(|_| ModemError::SendDataError(format!("Error in send_command({:?})", cmd)))?;
self.read_response(cmd.contains, cmd.timeout)
.write_bytes(cmd.text.as_bytes())
.map_err(|_| ModemError::SendDataError(format!("Error in send_command({})", cmd.text)))?;
let _ = self.serial
.write(&['\r' as u8])
.map_err(|_| ModemError::SendDataError(format!("Error in send_command({})", cmd.text)))?;
self.command_read_response()
}
fn handle_prompt(&mut self) -> Result<()> {
let mut prompt_buf = vec![0; 3];
let prompt_len = self.serial.read(&mut prompt_buf).map_err(|_| ModemError::ReadError)?;
let prompt = std::str::from_utf8(prompt_buf.as_slice()).unwrap_or("");
if prompt_len != 3 && prompt != "\r\n>" {
let msg = format!("Prompt error, expected \\r\\n>, got {:?}", prompt);
Err(ModemError::SendDataError(msg))
} else {
Ok(())
}
}
fn tcp_manual_send_data(&mut self, buf: &[u8]) -> Result<String> {
@ -122,18 +143,15 @@ impl<UART: serial::Uart> Modem<UART> {
.write("AT+CIPSEND\r".as_bytes())
.map_err(|_| ModemError::SendDataError("Error in tcp_manual_send_data ... AT_CIPSEND\\r".to_string()))?;
let send_prompt: String = self.serial.rx.reset(Duration::from_millis(3000))
.map(char::from)
.take_while(|c| *c != '>').collect();
let _ = self.handle_prompt()?;
if send_prompt != "\r\n" {
let msg = format!("Prompt error, expected \\r\\n, got {:?}", send_prompt.as_bytes());
return Err(ModemError::SendDataError(msg));
}
self.serial
.send_bytes(buf, Some(26_u8)) // 26_u8 = Ctrl+z - to end sending data
.write_bytes(buf)
.map_err(|err| ModemError::SendDataError(format!("{:?}", err)))?;
self.read_response(Some("SEND OK".to_string()), Duration::from_millis(3000))
self.serial
.write(&[26_u8]) // 26_u8 = Ctrl+z - to end sending data
.map_err(|err| ModemError::SendDataError(format!("{:?}", err)))?;
self.command_read_response()
}
pub fn gprs_status(&mut self) -> Result<String> {
@ -280,7 +298,8 @@ impl<UART: serial::Uart> Modem<UART> {
let _ = self.send_command(Command::http_set_content("application/json"));
let _ = self.send_command(Command::http_set_ssl(true));
let _ = self.send_command(Command::http_post_len(content.len(), 100000));
let _ = self.serial.send_bytes(content, Some(26));
let _ = self.serial.write_bytes(content);
let _ = self.serial.write(&[26_u8]);
let _ = self.send_command(Command::http_post());
self.send_command(Command::http_read_response())
}
@ -322,20 +341,15 @@ impl<UART: serial::Uart> Modem<UART> {
fn file_write(&mut self, buf: &[u8], path: &str, append: bool, input_time_sec: usize) -> Result<()> {
let cmd = Command::fs_file_write(path, append, buf.len(), input_time_sec);
let _ = self.serial
.send_bytes(cmd.text.as_bytes(), Some('\r' as u8))
.write(cmd.text.as_bytes())
.map_err(|err| ModemError::SendDataError(format!("File write error ({:?})", err)))?;
let send_prompt: String = self.serial.rx.reset(Duration::from_millis(3000))
.map(char::from)
.take_while(|c| *c != '>').collect();
if send_prompt == "" {
return Err(ModemError::SendDataError("Prompt empty, expected: \\r\\n".to_string()));
}
let _ = self.handle_prompt()?;
self.serial
.send_bytes(buf, None)
.write(buf)
.map_err(|err| ModemError::SendDataError(format!("Error sending bytes via serial ({:?})", err)))?;
let _ = self.read_response(Some("OK".to_string()), Duration::from_millis(3000));
let _ = self.command_read_response();
Ok(())
}

128
src/serial.rs
View file

@ -1,14 +1,14 @@
use std::error::Error;
use std::io;
use std::thread;
use std::time::{Duration, Instant};
use std::time::Duration;
use embedded_hal::serial::{Read, Write};
use esp_idf_hal::serial::{self, Rx, Tx};
#[derive(Debug)]
pub enum SerialError {
ReadError,
WriteError,
ReadError(String),
WriteError(String),
TimeoutError,
}
@ -20,121 +20,81 @@ impl std::fmt::Display for SerialError {
}
}
pub type Result<T> = std::result::Result<T, SerialError>;
pub struct RxIter<UART: serial::Uart> {
inner: Rx<UART>,
timeout: Duration,
}
impl<UART: serial::Uart> RxIter<UART> {
pub fn reset(&mut self, timeout: Duration) -> &mut Self {
self.timeout = timeout;
self
}
fn clear(&mut self) -> () {
println!("clearing serial rx");
self.reset(Duration::from_millis(500)).for_each(drop);
}
}
impl<UART: serial::Uart> Iterator for RxIter<UART> {
type Item = u8;
/// `nb` returns Ok(byte), or one of Err(WouldBlock) and Err(Other) which isn't of anyone's
/// interest, so the retry mechanism is triggered on _any_ error every 200ms until a byte is
/// received, or the timeout is reached.
fn next(&mut self) -> Option<Self::Item> {
let start = Instant::now();
loop {
match self.inner.read() {
Ok(b) => {
self.timeout = self.timeout.saturating_sub(start.elapsed());
break Some(b)
},
Err(_) => {
if start.elapsed() > self.timeout {
self.timeout = Duration::ZERO;
break None
}
thread::sleep(Duration::from_millis(200));
}
}
}
}
}
pub type Result<T> = nb::Result<T, SerialError>;
pub struct SerialIO<UART: serial::Uart> {
pub rx: RxIter<UART>,
pub rx: Rx<UART>,
pub tx: Tx<UART>,
}
impl<UART: serial::Uart> SerialIO<UART> {
pub fn new(tx: Tx<UART>, rx: Rx<UART>) -> Self {
Self {
rx: RxIter { inner: rx, timeout: Duration::from_millis(0) },
tx,
}
Self { rx, tx }
}
pub fn send_bytes(&mut self, payload: &[u8], eos: Option<u8>) -> Result<usize> {
pub fn write_bytes(&mut self, payload: &[u8]) -> Result<usize> {
let mut num_bytes = 0;
for b in payload.iter() {
nb::block!(self.tx.write(*b))
.map_err(|err| SerialError::WriteError)?;
self.tx.write(*b)
.map_err(|err| SerialError::WriteError(
format!("Error writing in serial port ({:?})", err)))?;
num_bytes += 1;
}
if num_bytes == payload.len() {
eos.map(|b| nb::block!(self.tx.write(b)));
Ok(num_bytes + if eos.is_none() { 0 } else { 1 })
Ok(num_bytes)
}
else {
Err(SerialError::WriteError)
Err(nb::Error::Other(
SerialError::WriteError(
"Written bytes shorter than payload length (write_bytes)".to_string()
)
))
}
}
/// Reads a whole line (that ends with \\n) within the given `timeout` passed on input.
pub fn read_line(&mut self, timeout: Duration) -> Result<String> {
let mut line: String = self.rx.reset(timeout)
.map(|b| char::from(b))
.take_while(|c| *c != '\n')
.collect();
fn read_bytes(&mut self, buf: &mut [u8]) -> Result<usize> {
let mut started_reading = false;
let mut count = 0;
let mut retries = 0;
// TODO: \r\n is true for sim800l, but might not be valud for other devices. Re-implement
// this function so that it can be used on all devices.
// \r must come right before \n on read; take_while excludes the matched element.
if line.ends_with('\r') {
line.push('\n');
Ok(line)
}
else if self.rx.timeout.as_millis() == 0 {
Err(SerialError::TimeoutError)
loop {
match self.rx.read() {
Ok(b) => {
started_reading = true;
if count < buf.len() {
buf[count] = b;
count += 1;
}
else { break }
},
Err(nb::Error::WouldBlock) => {
if started_reading || retries > READ_MAX_RETRIES { break }
else {
Err(SerialError::ReadError)
thread::sleep(Duration::from_millis(READ_WAIT_TIME));
retries += 1;
}
},
Err(nb::Error::Other(err)) => println!("Serial read error :: {:?}", err),
}
};
Ok(count)
}
}
const READ_MAX_RETRIES: usize = 5;
const READ_WAIT_TIME: u64 = 50;
impl<UART: serial::Uart> io::Read for SerialIO<UART> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let buf_size = buf.len();
let count = self.rx.reset(Duration::from_millis(1000))
.enumerate()
.map(|(i, b)| {
buf[i] = b;
i
})
.take_while(|i| i < &buf_size)
.count();
let count = nb::block!(self.read_bytes(buf))
.map_err(|_| io::Error::from(io::ErrorKind::Other))?;
Ok(count)
}
}
impl<UART: serial::Uart> io::Write for SerialIO<UART> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.send_bytes(buf, None)
nb::block!(self.write_bytes(buf))
.map_err(|_| io::Error::from(io::ErrorKind::Other))
}