diff --git a/src/conf.rs b/src/conf.rs
index 02ea741..2b449ec 100644
--- a/src/conf.rs
+++ b/src/conf.rs
@@ -19,10 +19,8 @@ pub struct Conf {
 pub fn load_config(path: &str) -> Result<Conf, Box<dyn std::error::Error>> {
     let settings = Config::builder()
         .add_source(config::File::with_name(path))
-        .build()?;
-
-    let conf = settings.try_deserialize::<Conf>()?;
-
-    
+	.build()?;
+            
+    let conf : Conf = settings.try_deserialize()?;
     Ok(conf)
 }
diff --git a/src/errors.rs b/src/errors.rs
new file mode 100644
index 0000000..9a9c179
--- /dev/null
+++ b/src/errors.rs
@@ -0,0 +1,36 @@
+use std::error::Error;
+use std::fmt;
+use redis::RedisError;
+
+#[derive(Debug)]
+pub enum LJError {
+    ConfigFileMissing,
+    RedisConnect(RedisError)
+}
+
+impl fmt::Display for LJError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+	use LJError::*;
+	
+	match self {
+	    ConfigFileMissing => {
+		write!(f, "first argument must be a TOML config file \
+			   (see copyme.Settings.toml)")
+	    },
+	    RedisConnect(err) => {
+		write!(f, "unable to connect to redis server: {err}")
+	    }
+	}
+    }
+}
+
+impl Error for LJError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+	use LJError::*;
+
+	match self {
+	    ConfigFileMissing => None,
+	    RedisConnect(err) => Some(err)
+	}
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 524f793..f3347b9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,3 @@
 pub mod conf;
 pub mod redis_ctrl;
+pub mod errors;
diff --git a/src/main.rs b/src/main.rs
index 374e9a0..6b5fa5e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,10 @@
-mod conf;
 ///
 /// Configure udev:
 /// https://github.com/Grix/helios_dac/blob/master/docs/udev_rules_for_linux.md
 ///
 mod redis_ctrl;
+mod conf;
+mod errors;
 
 use helios_dac::NativeHeliosDacController;
 use helios_dac::{
@@ -15,43 +16,41 @@ use helios_dac::{
 };
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
+use redis_ctrl::{RedisCtrl,Order};
+use conf::{load_config,Conf};
+use errors::LJError;
 
-use conf::{load_config, Conf};
-use redis_ctrl::{Order, RedisCtrl};
-
-const CENTER: (u16, u16) = (2000, 2000);
+const CENTER : (u16,u16) = (2000, 2000);
 
 pub fn main() {
-    let config = match load_config("Settings") {
-        Ok(c) => c,
-        Err(err) => {
-            panic!("Unable to load config file: {:?}", err)
-        }
-    };
-
-    let rs = match RedisCtrl::new() {
-        Ok(rs) => rs,
-        Err(err) => {
-            panic!("Unable to connect to redis: {:?}", err);
-        }
-    };
-
-    match run_dac(config, rs) {
-        Ok(()) => {}
-        Err(err) => {
-            panic!("Error: {:?}", err)
-        }
+    match run_all() {
+	Ok(()) => {},
+	Err(err) => {
+	    println!("Error: {}", err);
+	}
     }
 }
 
-fn run_dac(config: Conf, mut rs: RedisCtrl) -> Result<(), Box<dyn std::error::Error>> {
+fn run_all() -> Result<(), Box<dyn std::error::Error>> {
+    let Some(filename) = std::env::args().nth(1) else {
+	return Err(Box::new(LJError::ConfigFileMissing));
+    };    
+    let config = load_config(&filename)?;    
+    let rs = RedisCtrl::new()?;
+    
+    run_dac(config, rs)
+}
+
+fn run_dac(
+    config: Conf,
+    mut rs: RedisCtrl
+) -> Result<(), Box<dyn std::error::Error>> {
     let running = Arc::new(AtomicBool::new(true));
     let r = running.clone();
 
     ctrlc::set_handler(move || {
         r.store(false, Ordering::SeqCst);
-    })
-    .expect("Error setting Ctrl-C handler");
+    })?;
 
     let controller = NativeHeliosDacController::new()?;
     let devices = controller.list_devices()?;
@@ -60,18 +59,20 @@ fn run_dac(config: Conf, mut rs: RedisCtrl) -> Result<(), Box<dyn std::error::Er
 	println!("Unable to find an helios device");
 	return Ok(());
     };
-
+        
     let mut device = device.open()?;
-
+    
     while running.load(Ordering::SeqCst) {
-        let order = rs.get_order(0)?;
-        if order != Order::Draw {
-            println!("{:?}", order);
-        }
+	let order = rs.get_order(config.laser_id)?;
+	if order != Order::Draw {
+	    println!("{:?}", order);
+	}
 
-        let frame = get_next_frame(1000, &mut rs)?;
-
-        while let Ok(DeviceStatus::NotReady) = device.status() {}
+	let frame = get_next_frame(&config, 1000,
+				   &mut rs, order == Order::Black)?;
+	
+	while let Ok(DeviceStatus::NotReady) = device.status() {
+	}
         device.write_frame(frame)?;
     }
 
@@ -80,8 +81,14 @@ fn run_dac(config: Conf, mut rs: RedisCtrl) -> Result<(), Box<dyn std::error::Er
     Ok(())
 }
 
-fn get_next_frame(speed: u32, rs: &mut RedisCtrl) -> Result<Frame, Box<dyn std::error::Error>> {
-    let line = rs.get("/pl/0/0")?;
+fn get_next_frame(
+    config: &Conf,
+    speed: u32,
+    rs: &mut RedisCtrl,
+    _black: bool
+) -> Result<Frame, Box<dyn std::error::Error>> {
+    
+    let line = rs.get(&format!("/pl/{}/0", config.laser_id))?;
     let line: Vec<Point> = line.iter().map(tuple_to_point).collect();
 
     let mut line2 = vec![];
@@ -91,18 +98,20 @@ fn get_next_frame(speed: u32, rs: &mut RedisCtrl) -> Result<Frame, Box<dyn std::
         }
     }
 
+    println!("{:?}", line2);
+
     Ok(Frame::new(speed, line2))
 }
 
 fn tuple_to_point(tpl: &(f32, f32, u32)) -> Point {
     let (x, y, col) = tpl;
-
-    let r = (col >> 16) as u8;
-    let g = ((col >> 8) & 255) as u8;
-    let b = (col & 255) as u8;
-
-    let x = CENTER.0 + *x as u16;
-    let y = CENTER.1 + *y as u16;
+    
+    let r = (col >> 16) as u8 ;
+    let g = ((col >> 8) & 255) as u8 ;
+    let b = (col & 255) as u8 ;
+    
+    let x = CENTER.0 + *x as u16 * 2;
+    let y = CENTER.1 + *y as u16 * 2;
 
     if x >= 4096 || y >= 4096 {
         println!("WARN: coordinate out of range: {} {}", x, y);
diff --git a/src/redis_ctrl.rs b/src/redis_ctrl.rs
index 238bd8a..5653a0d 100644
--- a/src/redis_ctrl.rs
+++ b/src/redis_ctrl.rs
@@ -1,5 +1,6 @@
 use redis::{Client, Commands, Connection};
 use ron::de::from_str;
+use crate::errors::LJError;
 
 #[repr(u8)]
 #[derive(Debug, PartialEq)]
@@ -21,22 +22,22 @@ impl TryFrom<u8> for Order {
     fn try_from(value: u8) -> Result<Self, Self::Error> {
         use Order::*;
 
-        if value > 8 {
-            return Err("order out of range".to_string());
-        }
-
-        Ok(match value {
-            0 => Draw,
-            1 => Edh,
-            2 => Black,
-            3 => Grid,
-            4 => Resampler,
-            5 => ClientKey,
-            6 => Intensity,
-            7 => Kpps,
-            8 => ColorBalance,
-            _ => panic!("Can't be there"),
-        })
+	if value > 8 {
+	    return Err("order out of range".to_string());
+	}
+	
+	Ok(match value {
+	    0 => Draw,
+	    1 => Edh,
+	    2 => Black,
+	    3 => Grid,
+	    4 => Resampler,
+	    5 => ClientKey,
+	    6 => Intensity,
+	    7 => Kpps,
+	    8 => ColorBalance,
+	    _ => unreachable!()
+	})
     }
 }
 
@@ -49,8 +50,10 @@ pub struct RedisCtrl {
 
 impl RedisCtrl {
     pub fn new() -> Result<Self, Box<dyn std::error::Error>> {
-        let client = Client::open("redis://127.0.0.1/")?;
-        let connection = client.get_connection()?;
+        let client = Client::open("redis://127.0.0.1/")
+	    .map_err(| err | LJError::RedisConnect(err))?;
+        let connection = client.get_connection()
+	    .map_err(| err | LJError::RedisConnect(err))?;
         Ok(RedisCtrl { client, connection })
     }