diff --git a/firmware/Cargo.lock b/firmware/Cargo.lock
index ce4b34a..8d3da42 100644
--- a/firmware/Cargo.lock
+++ b/firmware/Cargo.lock
@@ -137,6 +137,7 @@ dependencies = [
  "crc 1.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "embedded-hal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libm 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "logos 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "nb 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "smoltcp 0.4.0 (git+https://github.com/m-labs/smoltcp?rev=cd893e6)",
  "tm4c129x 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -157,6 +158,26 @@ name = "libm"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "logos"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "logos-derive 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "logos-derive"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.44 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "managed"
 version = "0.5.1"
@@ -209,6 +230,11 @@ name = "rand_core"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "regex-syntax"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -285,6 +311,11 @@ name = "unicode-xid"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "utf8-ranges"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "vcell"
 version = "0.1.2"
@@ -342,6 +373,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum generic-array 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c68f0274ae0e023facc3c97b2e00f076be70e254bc851d972503b328db79b2ec"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum libm 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7fc7aa29613bd6a620df431842069224d8bc9011086b1db4c0e0cd47fa03ec9a"
+"checksum logos 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f494e22d293fa05db60b3fd95fb30e9409feb5672b56ce6f250f99d9fbae6b93"
+"checksum logos-derive 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)" = "13ff1b1068db09ee21d12baf55eccc0900a781a735273e0a606f6f4fbb32a322"
 "checksum managed 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "43e2737ecabe4ae36a68061398bf27d2bfd0763f4c3c837a398478459494c4b7"
 "checksum nb 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b1411551beb3c11dedfb0a90a0fa256b47d28b9ec2cdff34c25a2fa59e45dbdc"
 "checksum proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)" = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
@@ -350,6 +383,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rand 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c618c47cd3ebd209790115ab837de41425723956ad3ce2e6a7f09890947cacb9"
 "checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
 "checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
+"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum same-file 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d931a44fdaa43b8637009e7632a02adc4f2b2e0733c08caa4cf00e8da4a117a7"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
@@ -360,6 +394,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum tm4c129x 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7d430ed4ed06dd9fff3d4517a37343e1b53789218f2f608bf1e0432f67abf624"
 "checksum typenum 1.11.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6d2783fe2d6b8c1101136184eb41be8b1ad379e4657050b8aaff0c79ee7575f9"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
+"checksum utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b4ae116fef2b7fea257ed6440d3cfcff7f190865f170cdad00bb6465bf18ecba"
 "checksum vcell 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "876e32dcadfe563a4289e994f7cb391197f362b6315dc45e8ba4aa6f564a4b3c"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum volatile-register 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0d67cb4616d99b940db1d6bd28844ff97108b498a6ca850e5b6191a532063286"
diff --git a/firmware/Cargo.toml b/firmware/Cargo.toml
index ac7f3d3..3c14a69 100644
--- a/firmware/Cargo.toml
+++ b/firmware/Cargo.toml
@@ -19,6 +19,7 @@ cortex-m-semihosting = "0.3"
 byteorder = { version = "1.3", default-features = false }
 bit_field = "0.10"
 bare-metal = "0.2"
+logos = { version = "~0.9", default-features = false, features = ["export_derive"] }
 
 [dependencies.smoltcp]
 git = "https://github.com/m-labs/smoltcp"
diff --git a/firmware/src/command_parser.rs b/firmware/src/command_parser.rs
new file mode 100644
index 0000000..36be426
--- /dev/null
+++ b/firmware/src/command_parser.rs
@@ -0,0 +1,85 @@
+use logos::{Logos, Lexer};
+use super::session::ReportMode;
+
+#[derive(Logos, Debug, PartialEq)]
+enum Token {
+    #[end]
+    End,
+    #[error]
+    Error,
+
+    #[token = "Quit"]
+    Quit,
+    #[token = "show"]
+    Show,
+    #[token = "channel"]
+    Channel,
+    #[token = "report"]
+    Report,
+    #[token = "mode"]
+    Mode,
+    #[token = "off"]
+    Off,
+    #[token = "once"]
+    Once,
+    #[token = "continuous"]
+    Continuous,
+
+    #[regex = "[0-9]+"]
+    Number,
+}
+
+#[derive(Debug)]
+pub enum Error {
+    Parser,
+    UnexpectedEnd,
+    UnexpectedToken(Token),
+}
+
+#[derive(Debug)]
+pub enum CommandShow {
+    ReportMode,
+}
+
+#[derive(Debug)]
+pub enum Command {
+    Quit,
+    Show(CommandShow),
+    Report(ReportMode),
+}
+
+
+
+impl Command {
+    pub fn parse(input: &str) -> Result<Self, Error> {
+        let mut lexer = Token::lexer(input);
+
+        macro_rules! choice {
+            [$($token: tt => $block: stmt,)*] => {
+                match lexer.token {
+                    $(
+                        Token::$token => {
+                            lexer.advance();
+                            $block
+                        }
+                    )*
+                    Token::End => Err(Error::UnexpectedEnd),
+                    _ => Err(Error::UnexpectedToken(lexer.token))
+                }
+            }
+        }
+
+        choice![
+            Quit => Ok(Command::Quit),
+            Report => choice![
+                Mode => choice![
+                    End => Ok(Command::Show(CommandShow::ReportMode)),
+                    Off => Ok(Command::Report(ReportMode::Off)),
+                    Once => Ok(Command::Report(ReportMode::Once)),
+                    Continuous => Ok(Command::Report(ReportMode::Continuous)),
+                ],
+                End => Ok(Command::Report(ReportMode::Once)),
+            ],
+        ]
+    }
+}
diff --git a/firmware/src/main.rs b/firmware/src/main.rs
index 24d2e23..5fd4ffd 100644
--- a/firmware/src/main.rs
+++ b/firmware/src/main.rs
@@ -34,6 +34,10 @@ pub fn panic_fmt(info: &core::panic::PanicInfo) -> ! {
 mod board;
 use self::board::{gpio::Gpio, systick::get_time};
 mod ethmac;
+mod command_parser;
+use command_parser::{Command, CommandShow};
+mod session;
+use self::session::{Session, SessionOutput};
 mod ad7172;
 
 pub struct UART0;
@@ -129,6 +133,7 @@ fn main() -> ! {
                 writeln!(stdout, "Corrupt ADC id: {:04X}", id).unwrap(),
         };
     }
+
     let mut hardware_addr = EthernetAddress(board::get_mac_address());
     if hardware_addr.is_multicast() {
         println!("programmed MAC address is invalid, using default");
@@ -166,21 +171,20 @@ fn main() -> ! {
     create_socket!(sockets, tcp_rx_storage5, tcp_tx_storage5, tcp_handle5);
     create_socket!(sockets, tcp_rx_storage6, tcp_tx_storage6, tcp_handle6);
     create_socket!(sockets, tcp_rx_storage7, tcp_tx_storage7, tcp_handle7);
-    let handles = [
-        tcp_handle0,
-        tcp_handle1,
-        tcp_handle2,
-        tcp_handle3,
-        tcp_handle4,
-        tcp_handle5,
-        tcp_handle6,
-        tcp_handle7,
+    let mut sessions_handles = [
+        (Session::new(), tcp_handle0),
+        (Session::new(), tcp_handle1),
+        (Session::new(), tcp_handle2),
+        (Session::new(), tcp_handle3),
+        (Session::new(), tcp_handle4),
+        (Session::new(), tcp_handle5),
+        (Session::new(), tcp_handle6),
+        (Session::new(), tcp_handle7),
     ];
 
     let mut read_times = [0, 0];
     let mut data = None;
     // if a socket has sent the latest data
-    let mut socket_pending = [false; 8];
     loop {
         let _ = adc.data_ready()
             .and_then(|channel|
@@ -190,8 +194,8 @@ fn main() -> ! {
                         read_times[0] = read_times[1];
                         read_times[1] = now;
                         data = Some((now, Ok((channel, new_data))));
-                        for p in socket_pending.iter_mut() {
-                            *p = true;
+                        for (session, _) in sessions_handles.iter_mut() {
+                            session.set_report_pending();
                         }
                     })
                 ).unwrap_or(Ok(()))
@@ -199,17 +203,43 @@ fn main() -> ! {
             .map_err(|e| {
                 let now = get_time();
                 data = Some((now, Err(e)));
-                for p in socket_pending.iter_mut() {
-                    *p = true;
+                for (session, _) in sessions_handles.iter_mut() {
+                    session.set_report_pending();
                 }
             });
-        for (&tcp_handle, pending) in handles.iter().zip(socket_pending.iter_mut()) {
-            let socket = &mut *sockets.get::<TcpSocket>(tcp_handle);
+        for (session, tcp_handle) in sessions_handles.iter_mut() {
+            let socket = &mut *sockets.get::<TcpSocket>(*tcp_handle);
             if !socket.is_open() {
+                if session.is_dirty() {
+                    // Reset a previously uses session/socket
+                    *session = Session::new();
+                }
                 socket.listen(23).unwrap()
             }
 
-            if socket.may_send() && *pending {
+            if socket.may_recv() && socket.may_send() {
+                let command = socket.recv(|buf| session.feed(buf));
+
+                match command {
+                    Ok(SessionOutput::Nothing) => {}
+                    Ok(SessionOutput::Command(Command::Quit)) =>
+                        socket.close(),
+                    Ok(SessionOutput::Command(Command::Report(mode))) => {
+                        let _ = writeln!(socket, "Report mode: {:?}", mode);
+                    }
+                    Ok(SessionOutput::Command(Command::Show(CommandShow::ReportMode))) => {
+                        let _ = writeln!(socket, "Report mode: {:?}", session.report_mode());
+                    }
+                    Ok(SessionOutput::Command(command)) => {
+                        let _ = writeln!(socket, "Not implemented: {:?}", command);
+                    }
+                    Ok(SessionOutput::Error(e)) => {
+                        let _ = writeln!(socket, "Command error: {:?}", e);
+                    }
+                    Err(_) => {}
+                }
+            }
+            if socket.may_send() && session.is_report_pending() {
                 match &data {
                     Some((time, Ok((channel, input)))) => {
                         let interval = read_times[1] - read_times[0];
@@ -223,7 +253,7 @@ fn main() -> ! {
                     }
                     None => {}
                 }
-                *pending = false;
+                session.mark_report_sent();
             }
         }
         match iface.poll(&mut sockets, Instant::from_millis((get_time() / 1000) as i64)) {
diff --git a/firmware/src/session.rs b/firmware/src/session.rs
new file mode 100644
index 0000000..0f18e0b
--- /dev/null
+++ b/firmware/src/session.rs
@@ -0,0 +1,124 @@
+use super::command_parser::{Command, Error as ParserError};
+
+
+const MAX_LINE_LEN: usize = 64;
+
+struct LineReader {
+    buf: [u8; MAX_LINE_LEN],
+    pos: usize,
+}
+
+impl LineReader {
+    pub fn new() -> Self {
+        LineReader {
+            buf: [0; MAX_LINE_LEN],
+            pos: 0,
+        }
+    }
+
+    pub fn feed(&mut self, c: u8) -> Option<&str> {
+        if (c == 13 || c == 10) {
+            // Enter
+            if self.pos > 0 {
+                let len = self.pos;
+                self.pos = 0;
+                core::str::from_utf8(&self.buf[..len]).ok()
+            } else {
+                None
+            }
+        } else if self.pos < self.buf.len() {
+            // Add input
+            self.buf[self.pos] = c;
+            self.pos += 1;
+            None
+        } else {
+            // Buffer is full, ignore
+            None
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum ReportMode {
+    Off,
+    Once,
+    Continuous,
+}
+
+pub enum SessionOutput {
+    Nothing,
+    Command(Command),
+    Error(ParserError),
+}
+
+impl From<Result<Command, ParserError>> for SessionOutput {
+    fn from(input: Result<Command, ParserError>) -> Self {
+        input.map(SessionOutput::Command)
+            .unwrap_or_else(SessionOutput::Error)
+    }
+}
+
+pub struct Session {
+    reader: LineReader,
+    report_mode: ReportMode,
+    report_pending: bool,
+}
+
+impl Session {
+    pub fn new() -> Self {
+        Session {
+            reader: LineReader::new(),
+            report_mode: ReportMode::Off,
+            report_pending: false,
+        }
+    }
+
+    pub fn is_dirty(&self) -> bool {
+        self.reader.pos > 0
+    }
+
+    pub fn report_mode(&self) -> ReportMode {
+        self.report_mode
+    }
+
+    pub fn set_report_pending(&mut self) {
+        self.report_pending = true;
+    }
+
+    pub fn is_report_pending(&self) -> bool {
+        match self.report_mode {
+            ReportMode::Off => false,
+            _ => self.report_pending,
+        }
+    }
+
+    pub fn mark_report_sent(&mut self) {
+        self.report_pending = false;
+        match self.report_mode {
+            ReportMode::Once =>
+                self.report_mode = ReportMode::Off,
+            _ => {}
+        }
+    }
+
+    pub fn feed(&mut self, buf: &[u8]) -> (usize, SessionOutput) {
+        let mut buf_bytes = 0;
+        for (i, b) in buf.iter().enumerate() {
+            buf_bytes = i + 1;
+            match self.reader.feed(*b) {
+                Some(line) => {
+                    let command = Command::parse(line);
+                    match command {
+                        Ok(Command::Report(mode)) => {
+                            self.report_mode = mode;
+                        }
+                        _ => {}
+                    }
+                    return (buf_bytes, command.into());
+                }
+                None => {}
+            }
+        }
+        (buf_bytes, SessionOutput::Nothing)
+    }
+}