Some extra debugging output and cleanups

Cargo.toml

@@ -5,16 +5,38 @@ edition = "2024"
 host = "x86_64-unknown-linux-gnu"
 
 [dependencies]
-sdl3 = {version = "0.17", features = ["ttf"]}
-serde = "1.0"
-gtfs-structures = "0.47"
 chrono = "0.4"
-log = "0.4"
-zip = "8.3"
 csv = "1.4"
+gtfs-structures = "0.47"
+gtfs-realtime = "0.2"
+log = "0.4"
+prost = "0.14"
+prost-types = "0.14"
+reqwest = { version = "0.11", features = ["blocking"] }
+sdl3 = {version = "0.17", features = ["ttf"]}
+serde = { version = "1.0", features = ["derive"]}
+serde_json = "1.0"
+time-format = "1.2"
+yaml_serde = "0.10"
+zip = "8.3"
 
 [profile.dev]
-opt-level = 0
+opt-level = 1
 
 [profile.release]
 opt-level = 3
+
+[target.aarch64-unknown-linux-gnu]
+cc = "aarch64-linux-gnu-gcc"
+cxx = "aarch64-linux-gnu-g++"
+ar = "aarch64-linux-gnu-ar"
+# ranlib = "aarch64-linux-gnu-ranlib"
+linker = "aarch64-linux-gnu-gcc"
+
+
+[target.arm-unknown-linux-gnueabihf]
+cc = "arm-linux-gnueabihf-gcc"
+cxx = "arm-linux-gnueabihf-g++"
+ar = "arm-linux-gnueabihf-ar"
+# ranlib = "arm-linux-gnueabihf-ranlib"
+linker = "arm-linux-gnueabihf-gcc"

Cross.toml

@@ -1,8 +0,0 @@
-[build]
-default-target = "aarch64-unknown-linux-gnu"   # use this target if none is explicitly provided
-pre-build = [                                  # additional commands to run prior to building the package
-    "dpkg --add-architecture $CROSS_DEB_ARCH", 
-    "apt update",
-    "apt --assume-yes install apt-utils:$CROSS_DEB_ARCH",
-    "apt --assume-yes install libsdl3-dev:$CROSS_DEB_ARCH"
-]                 

readme.md

@@ -6,21 +6,28 @@
 
 ## Install ARM toolchains:
 
-```
+```bash
-cargo install cross
+$ rustup target add aarch64-unknown-linux-gnu
-rustup target add aarch64-unknown-linux-gnu   # 64-bit Pi OS
+$ rustup target add arm-unknown-linux-gnueabihf
-rustup target add armv7-unknown-linux-gnueabihf  # 32-bit Pi 2/3/4 OS
-rustup target add arm-unknown-linux-gnueabihf    # ARMv6 (Pi Zero/1)
 
-sudo apt-get update
+
-sudo apt-get install gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf
+$ sudo dpkg --add-architecture arm64
+$ sudo dpkg --add-architecture armhf
+
+$ sudo apt update 
+$ sudo apt-get install gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf \
+                       libc6-arm64-cross libc6-dev-arm64-cross gcc-aarch64-linux-gnu \
+                       libc6-armhf-cross libc6-dev-armhf-cross gcc-arm-linux-gnueabihf \
+                       libssl-dev libssl-dev:arm64 libsdl3-dev:arm64 libssl-dev:armhf libsdl3-dev:armhf
 ```
 
 ## Cross-compile
 
-```
+ARM64
-# 2) Build
+```bash
-~/.cargo/bin/cross build --target aarch64-unknown-linux-gnu --release
+$ export PKG_CONFIG_SYSROOT_DIR=/usr/aarch64-linux-gnu/
-~/.cargo/bin/cross build --target armv7-unknown-linux-gnueabihf --release
+$ cargo build --target aarch64-unknown-linux-gnu --release
-~/.cargo/bin/cross build --target arm-unknown-linux-gnueabihf --release
+
+$ export PKG_CONFIG_SYSROOT_DIR=/usr/arm-linux-gnueabihf/
+$ cargo build --target arm-unknown-linux-gnueabihf --release
 ```

resources/dublinbus.yaml

@@ -0,0 +1,18 @@
+screen:
+  width: 1920
+  height: 720
+  font-path: "resources/jd_lcd_rounded/jd-lcd-rounded.ttf"
+
+gtfs:
+  routes: 
+  - 15A
+  - F1
+  - F2
+  stops:
+  - 1114
+  - 2410
+  data-folder: "/home/nahuel/Downloads"
+  gtfs-url: "https://www.transportforireland.ie/transitData/Data/GTFS_Realtime.zip"
+  realtime-url: "https://api.nationaltransport.ie/gtfsr/v2/gtfsr"
+  realtime-api-key: "Not defined"
+  refresh-seconds: 61

src/config.rs

@@ -0,0 +1,51 @@
+use crate::{gtfs, renderer};
+use serde::{Serialize, Deserialize};
+use std::fs;
+use yaml_serde;
+
+
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
+pub struct Config {
+    #[serde(rename = "gtfs")]
+    pub gtfs_prefs: gtfs::structs::Preferences,
+
+    #[serde(rename = "screen")]
+    pub screen_prefs: renderer::structs::Prefs,
+}
+
+#[derive (Debug)]
+pub struct Error {
+    pub message: String
+}
+
+
+impl From<std::io::Error> for Error {
+    fn from(value: std::io::Error) -> Self {
+        return Error {
+            message: value.to_string(),
+        };
+    }
+}
+
+impl From<yaml_serde::Error> for Error {
+    fn from(value: yaml_serde::Error) -> Self {
+        return Error {
+            message: value.to_string(),
+        }
+    }
+}
+
+impl From<sdl3::Error> for Error {
+    fn from(value: sdl3::Error) -> Self {
+        return Error {
+            message: value.to_string(),
+        }
+    }
+}
+
+
+pub fn load_config(config_name: String) -> Result<Config, Error> {
+    let config_text = fs::read_to_string(config_name)?;
+    let config = yaml_serde::from_str(config_text.as_ref())?;
+    return Ok(config);
+}

src/gtfs/loader.rs

@@ -1,6 +1,6 @@
 use log::debug;
 use gtfs_structures::{Calendar, CalendarDate, RawStopTime, RawTrip, Route, Stop};
-use serde::de::{DeserializeOwned, value::MapAccessDeserializer};
+use serde::de::{DeserializeOwned};
 use std::{
     collections::{HashMap, HashSet},
     fs::File,

src/gtfs/mod.rs

@@ -1,30 +1,31 @@
 mod arrival;
 mod loader;
 mod utils;
+mod refresher;
+mod realtime;
 pub mod structs;
-use chrono::{DateTime, Local, NaiveTime, Timelike};
+use chrono::{DateTime, Local, Timelike};
-use log::{debug};
+use log::{debug, trace, warn};
-use std::{
+use std::{collections::{HashMap, HashSet}, fs::File };
-    collections::{HashMap, HashSet}, fs::File, io::Error
-};
 use gtfs_structures::{Exception, RawTrip};
-
+use crate::gtfs::{loader::load_gtfs, structs::{Arrival, Gtfs, Preferences, Error}};
-use crate::gtfs::{loader::load_gtfs, structs::{Arrival, Gtfs, Preferences}};
 
 
-impl Gtfs {
+impl Gtfs<'_> {
 
     pub fn get_next_arrivals_for(&self, target_datetime: &DateTime<Local>) -> Option<Vec<Arrival<'_>>> {
         let naive_target = target_datetime.naive_local();
         let target_date = naive_target.date();
         
         // Find which calendars apply
+        debug!("Looking for calendars that apply to date {:#?}", target_date);
         let mut active_service_ids: HashSet<String> = HashSet::new();
         for (id, calendar) in self.calendar.iter() {
             if calendar.valid_weekday(target_date) 
             && calendar.start_date <= target_date 
             && calendar.end_date > target_date {
                 active_service_ids.insert(id.to_string());
+                debug!("Matched calendar: {:#?}", calendar);
             } 
         }
         debug!("Found {} services active today", active_service_ids.len());
@@ -44,7 +45,7 @@ impl Gtfs {
                 }
             }                
         }
-        debug!("After exceptions, there are now {} services active", active_service_ids.len());
+        debug!("After exceptions, there are now {} services active: {:#?}", active_service_ids.len(), active_service_ids);
 
         // Find the trips happening on these calendars
         let mut trips: HashMap<&String, &RawTrip> = HashMap::new();
@@ -66,7 +67,6 @@ impl Gtfs {
         for (_id, stop_time) in self.stop_times.iter() {
             if trips.contains_key(&stop_time.trip_id) {
                 let stop_timestamp = stop_time.departure_time.or(stop_time.arrival_time)?;
-                debug!("Stop timestamp {} current timestamp {}", stop_timestamp, current_timestamp);
                 let trip= &self.trips.get(&stop_time.trip_id).unwrap();
                 if current_timestamp < stop_timestamp.into() {
                     let arrival: Arrival = Arrival {
@@ -76,24 +76,41 @@ impl Gtfs {
                         trip: &trip,
                         departure_time: stop_timestamp.into()
                     };
+                    trace!("{:#?}: Arrival to {:#?} for trip ID {:#?}.", 
+                            format!("{:02}:{:02}", (arrival.departure_time/3600) as u32, ((arrival.departure_time / 60) % 60) as u32),
+                            arrival.trip.trip_headsign.as_ref().unwrap(),
+                            arrival.trip.id);
                     arrivals.push(arrival);                        
                 }
             }
         }
+
         arrivals.sort();
+
         debug!("Found {} arrivals", arrivals.len());
 
+        // Update real-time deltas
+
+        let realtime_result = self.realtime_update(&mut arrivals);
+        if realtime_result.is_err() {
+            warn!("Unable to update realtime arrivals: {:#?}", realtime_result.err().unwrap()._message)
+        }
+
         return Some(arrivals);
     }
         
 
     /// Load a GTFS structure from a zip file
-    pub fn load(src_file: &str, prefs: &Preferences) -> Result<Gtfs, Error> {
+    pub fn load(prefs: &Preferences) -> Result<Gtfs, Error> {
+
+        _ = refresher::refresh(prefs);
+
         // Open zip file
-        let zip_file = File::open(src_file)?;
+        let zip_file = File::open(prefs.gtfs_file_path()?)?;
         let mut zip_reader = zip::ZipArchive::new(zip_file)?;
 
         let mut gtfs: Gtfs = Gtfs {
+            preferences: prefs,
             agencies: Vec::new(),
             calendar: HashMap::new(),
             calendar_dates: HashMap::new(),

src/gtfs/realtime.rs

@@ -0,0 +1,84 @@
+use log::debug;
+/***
+ * Implementation of GTFS-R polling 
+  */
+use reqwest::{StatusCode, blocking::Client};
+use std::{collections::HashMap, time::Duration};
+
+use crate::gtfs::{self, structs::{Arrival, Error, Gtfs}};
+
+impl Gtfs<'_> {
+    pub(crate) fn realtime_update (&self, arrivals: &mut Vec<Arrival<'_>>) -> Result<(), gtfs::structs::Error>{
+
+        // Poll GTFS-R API
+        let client = Client::builder()
+            .timeout(Duration::from_secs(10))
+            .connect_timeout(Duration::from_secs(5))
+            .build()?;
+        
+        let response = client
+            .get(&self.preferences.realtime_url)
+            .header("x-api-key", &self.preferences.realtime_api_key)
+            .send()?;
+
+        if response.status() != StatusCode::OK {
+            return Err(Error {
+                _message : format!("HTTP Respomse: {:#?}. Payload: \n{:#?}\n", response.status(), response.text().unwrap())
+            })
+        }
+
+        // Parse response
+        let response_bytes= response.bytes()?;
+        let data: Result<gtfs_realtime::FeedMessage, prost::DecodeError> = prost::Message::decode(response_bytes.as_ref());
+        if data.is_err() {
+            return Err(Error {  
+                _message : format! ("Error loading realtime prtobuf: {:#?}", data.err().unwrap())
+            })
+        }
+
+
+        // Build a map of (trip, stop) -> Arrival for faster lookup
+        let mut lookup: HashMap<(String, String), usize> = HashMap::new();
+        let num_arrivals = arrivals.len();
+        for i in 0..num_arrivals {
+            let arrival = arrivals.get(i).unwrap();
+            lookup.insert((arrival.trip.id.clone(), arrival.stop.id.clone()), i);
+        }
+
+        // Match deltas to existing arrivals
+        let entities = data.unwrap().entity;
+        debug!("Loaded {} entities from realtime update.", entities.len());
+        for entity  in entities {
+            if entity.trip_update.is_some() && entity.stop.is_some() {
+                let trip_update = entity.trip_update.unwrap();
+                
+                // Look up the entry in arrivals for the current
+                for stop_update in trip_update.stop_time_update {
+                    if stop_update.stop_id.is_none() {
+                        continue;
+                    } 
+                    let trip_id = trip_update.trip.trip_id.clone().unwrap();
+                    let stop_id = stop_update.stop_id.unwrap();
+                    let key = (trip_id, stop_id); 
+                    if lookup.contains_key(&key) {
+                       
+                        // Update the arrival time
+                        let arrival_index = lookup.get(&key);
+                        let arrival: &mut Arrival<'_> = arrivals.get_mut(*arrival_index.unwrap()).unwrap();
+                        if let Some(update) = stop_update.departure.or(stop_update.arrival) {
+                            let new_time = (((arrival.departure_time as i64) 
+                                                        + (update.delay.unwrap_or(0) as i64))) as u32;
+                            debug!("Updated arrival time of {:#?} by {}s", &key, update.delay.unwrap());
+                            arrival.departure_time = new_time;
+                        }
+                    }
+                }
+            }
+        }
+
+        return Ok(());
+        }
+    }
+
+
+

src/gtfs/refresher.rs

@@ -0,0 +1,61 @@
+use log::{debug, info};
+use time_format::format_common_utc;
+use std::{fs::{self}, time::{Duration, SystemTime, UNIX_EPOCH}};
+use crate::gtfs::structs::{Error, Preferences};
+use reqwest::{StatusCode, blocking::Client};
+
+
+pub(crate) fn refresh(prefs: &Preferences) -> Result<(), Error> {
+
+    let mut modified_timestamp: SystemTime = SystemTime::UNIX_EPOCH;
+    let gtfs_file_name = prefs.gtfs_file_path()?;
+
+    // Obtain the GTFS zip's creation time.
+    let metadata = fs::metadata(&gtfs_file_name);
+    if metadata.is_ok() {
+        modified_timestamp = metadata?.modified()?;
+    }
+
+    let modified_seconds = modified_timestamp.duration_since(UNIX_EPOCH).unwrap().as_secs() as i64;
+    let modified_header =  format_common_utc(modified_seconds, time_format::DateFormat::HTTP).unwrap();
+
+    debug!("Using if-modified-since: {}", modified_header);
+
+    // request updates from the server if-modified-since last time
+    let client = Client::builder()
+        .timeout(Duration::from_secs(30))
+        .connect_timeout(Duration::from_secs(5))
+        .build()?;
+    
+    let mut response = client
+        .get(&prefs.gtfs_url)
+        .header(reqwest::header::IF_MODIFIED_SINCE, modified_header)
+        .send()
+        .unwrap();
+
+    if response.status() == StatusCode::NOT_MODIFIED {
+        debug!("GTFS data is still up-to-date");
+        return Ok(());
+    }
+
+    if response.status() == StatusCode::OK {
+        info!("Refreshing GTFS data");
+        // Stream the response data into a temp file and swap them
+
+        let tmp_full_file_name = format!("{}.new", &gtfs_file_name);
+        let mut tmp_file = fs::File::create(&tmp_full_file_name)?;
+
+        _ = response.copy_to(&mut tmp_file)?;
+        drop(tmp_file);
+
+        if fs::exists(&gtfs_file_name)? {
+            _ = fs::remove_file(&gtfs_file_name);
+        }
+        _ = fs::rename(&tmp_full_file_name, &gtfs_file_name);
+        info!("GTFS data refreshed");
+        return Ok(());
+    }
+
+    let errmsg = format!("GET on {} returned result code {}", prefs.gtfs_url, response.status());
+    return Err(Error { _message: errmsg });
+}    

src/gtfs/structs.rs

@@ -1,18 +1,89 @@
 use std::collections::{HashMap, HashSet};
-
-use chrono::NaiveTime;
 use gtfs_structures::{Agency, Calendar, CalendarDate, RawStopTime, RawTrip, Route, Stop};
+use log::error;
+use serde::{Serialize, Deserialize};
+use zip::result::ZipError;
+
+
+#[derive(Debug)]
+pub struct Error {
+    pub(crate) _message: String,
+}
+
+impl From<std::io::Error> for Error {
+    fn from(value: std::io::Error) -> Self {
+        return Error { _message: value.to_string() }
+    }
+}
+
+impl From<reqwest::Error> for Error {
+    fn from(value: reqwest::Error) -> Self {
+        return Error { _message: value.to_string() }
+    }
+}
+
+impl From<ZipError> for Error {
+    fn from(value: ZipError) -> Self {
+        return Error { _message: value.to_string() }
+    }
+}
+
+impl From<serde_json::Error> for Error {
+    fn from(value: serde_json::Error) -> Self {
+        return Error { _message: value.to_string() }
+    }
+}
+
 
 // This is to store the preferences for the GTFS(-R) side of the code.
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
 pub struct Preferences {
+    #[serde(rename = "routes")]
     pub route_numbers: HashSet<String>,
+
+    #[serde(rename = "stops")]
     pub stop_codes: HashSet<String>,
+
+    #[serde(rename = "data-folder")]
+    pub  data_folder: String,
+
+    #[serde(rename = "gtfs-url")]
+    pub gtfs_url: String,
+
+    #[serde(rename = "realtime-url")]
+    pub realtime_url: String,
+
+    #[serde(rename = "realtime-api-key")]
+    pub realtime_api_key: String,
+
+    #[serde(rename = "refresh-seconds")]
+    pub refresh_seconds: u64,
+}
+
+// Utility functions
+impl Preferences {
+    pub fn gtfs_file_name(&self) -> Result<String, Error> {
+        let file_name_part = self.gtfs_url.split("/").last();
+        if file_name_part.is_none() {
+            error!("The config for gtfs-url is not a valid URL: {}", self.gtfs_url);
+            return Err(Error {_message: String::from("Failed to refresh GTFS data")});
+        } 
+        return Ok(String::from(file_name_part.unwrap()));
+    }
+
+    pub fn gtfs_file_path(&self) -> Result<String, Error> {
+        return Ok(format!("{}/{}", self.data_folder, self.gtfs_file_name()?));
+    }
+
 }
 
 
 // The main GTFS struct. This is similar to (but not exactly) gtfs-structures::Gtfs because we don't need everything
 #[derive(Debug)]
-pub struct Gtfs {
+pub struct Gtfs<'a> {
+    /// A copy of the preferences struct
+    pub(crate) preferences: &'a Preferences,
+
     /// All agencies. They can not be read by `agency_id`, as it is not a required field
     pub(crate) agencies: Vec<Agency>,
     /// All Calendar by `service_id`
@@ -32,7 +103,7 @@ pub struct Gtfs {
 
 #[derive(Debug)]
 pub struct Arrival<'a> {
-    pub departure_time: i64,
+    pub departure_time: u32,
     pub route: &'a Route,
     pub stop: &'a Stop,
     pub stop_time: &'a RawStopTime,

src/gtfs/utils.rs

@@ -1,7 +1,7 @@
 use std::collections::HashSet;
 use crate::gtfs::Gtfs;
 
-pub fn stop_ids_from_codes(gtfs: &Gtfs, stop_codes: &HashSet<String>) -> HashSet<String> {
+pub(crate) fn stop_ids_from_codes(gtfs: &Gtfs, stop_codes: &HashSet<String>) -> HashSet<String> {
     let mut ids: HashSet<String> = HashSet::new();
 
     for stop in &gtfs.stops {
@@ -13,7 +13,7 @@ pub fn stop_ids_from_codes(gtfs: &Gtfs, stop_codes: &HashSet<String>) -> HashSet
     return ids;
 }
 
-pub fn route_ids_from_numbers(gtfs: &Gtfs, route_numbers: &HashSet<String>) -> HashSet<String> {
+pub(crate) fn route_ids_from_numbers(gtfs: &Gtfs, route_numbers: &HashSet<String>) -> HashSet<String> {
     let mut ids: HashSet<String> = HashSet::new();
 
     for route in &gtfs.routes {

src/main.rs

@@ -1,12 +1,12 @@
 mod gtfs;
 mod renderer;
-use std::{collections::HashSet, ops::Add, os::unix::process::ExitStatusExt, process, thread::Builder, time::SystemTime};
+mod config;
-use chrono::{DateTime, Duration, Local, NaiveTime, Timelike};
+use std::{ops::Add, process, thread::Builder, time::SystemTime};
-use log::{Metadata, Record, debug, error, info};
+use chrono::{DateTime, Duration, Local, NaiveTime};
+use log::{Level, Metadata, Record, error, info};
 use sdl3::event::Event;
-use crate::{gtfs::structs::{Arrival, Gtfs}, renderer::structs::{DisplayData, DisplayEntry, Screen}};
+use crate::{config::load_config, gtfs::structs::{Arrival, Gtfs}, renderer::structs::{DisplayData, DisplayEntry, Screen}};
 
-const SRC_FILE: &str = "/home/nahuel/Downloads/GTFS_Realtime.zip";
 const NUM_ARRIVALS: usize = 4;
 
 // Custom Event to signal data refresh
@@ -31,8 +31,6 @@ fn refresh_schedule<'a>(gtfs: &'a Gtfs, screen : &mut Screen<'a>) -> Option<Vec<
     next_arrivals.sort();
 
     // Create the DisplayData structure to render the information to screen
-    let now =Local::now();
-    let current_time: i64 =  (now.hour() * 3600 + now.minute() * 60 + now.second()).into();
     let mut display_data: DisplayData = DisplayData {
         lines: Vec::<DisplayEntry>::new(),
         status: None
@@ -46,7 +44,7 @@ fn refresh_schedule<'a>(gtfs: &'a Gtfs, screen : &mut Screen<'a>) -> Option<Vec<
                     .or(Option::Some(String::from("Unknown")
                 ))).unwrap(),
                 route: arrival.route.short_name.clone().or(arrival.route.long_name.clone()).unwrap(),
-                due_in: (arrival.departure_time - current_time) / 60,
+                departure_time: arrival.departure_time,
             }
         }));
 
@@ -60,8 +58,8 @@ fn main() {
     static MY_LOGGER: MyLogger = MyLogger;
     struct MyLogger;
     impl log::Log for MyLogger {
-        fn enabled(&self, _metadata: &Metadata) -> bool {
+        fn enabled(&self, metadata: &Metadata) -> bool {
-            true
+            return metadata.level() < Level::Trace;
         }
 
         fn log(&self, record: &Record) {
@@ -80,31 +78,35 @@ fn main() {
     }
     log::set_max_level(log::LevelFilter::Trace);
 
-    // Create preferences structures from config
-    let gtfs_prefs = gtfs::structs::Preferences  {
-        route_numbers: HashSet::from([String::from("15A"), String::from("F1"), String::from("F2"), String::from("F3")]),
-        stop_codes: HashSet::from([String::from("1117")])
-    };
 
-    let screen_prefs = renderer::structs::Prefs {
+    let config_result = load_config(String::from("resources/dublinbus.yaml"));
-        font_path: String::from("resources/jd_lcd_rounded/jd-lcd-rounded.ttf"),
+    if config_result.is_err() {
-        screen_width: 1920,
+        error!("Error loading the config file: {:#?}", config_result.err());
-        screen_height: 720,
+        process::exit(-1);
-    };
+    }
+    // Create preferences structures from config
+    let config = config_result.unwrap();
+    let gtfs_prefs = config.gtfs_prefs;
+    let screen_prefs = config.screen_prefs;
 
     // Init GTFS static info
     info!("Loading GTFS data...");
-    let res = Gtfs::load(SRC_FILE, &gtfs_prefs);
+    let res = Gtfs::load(&gtfs_prefs);
 
     if let Err(e) = res {
-        error!("Error loading GTFS data: {}", e);
+        error!("Error loading GTFS data: {:#?}", e);
         process::exit(-1);
     } 
     let gtfs = res.unwrap();
 
     // Init screen
     info!("Initializing screen...");
-    let mut screen = Screen::init(&screen_prefs);
+    let screen_result = Screen::init(&screen_prefs);
+    if let Err(e) = screen_result {
+        error!("Error initializing video: {}", e.message);
+        process::exit(-1);
+    }
+    let mut screen = screen_result.unwrap();
     info!("Startup done.");
 
     // Register our custom event and obtain the event-related objects to interact with the event loop
@@ -117,7 +119,7 @@ fn main() {
         .name("updater".to_string())
         .spawn(move || { 
             loop {
-                std::thread::sleep(std::time::Duration::new(60,0));
+                std::thread::sleep(std::time::Duration::new(gtfs_prefs.refresh_seconds,0));
                 let event = RefreshDataEvent {};
                 let send_result = event_sender.push_custom_event(event);
                 if send_result.is_err() {

src/renderer/mod.rs

@@ -1,20 +1,19 @@
-
 pub mod structs;
-use std::cmp::min;
+use std::{cmp::min};
-
+use chrono::{Datelike, Local, Timelike};
+use log::{error, trace, warn};
 use sdl3::{Sdl, pixels::Color, rect::Rect};
 use structs::{Prefs, DisplayData};
 
-use crate::renderer::structs::Screen;
+use crate::{config::Error, renderer::structs::Screen};
 
-const LINE_COUNT: i32 = 6;
+const LINE_COUNT: i32 = 5;
 const COLOR_LCD_AMBER   : Color = Color::RGB(0xf4, 0xcb, 0x60);
 const COLOR_LCD_GREEN   : Color = Color::RGB(0xb3, 0xff, 0x00);
 const COLOR_LCD_RED     : Color = Color::RGB(0xff, 0x3a, 0x4a);
-
+const COLOR_BACKGROUND  : Color = Color::RGB(0x0,  0x0,  0x0 );
-//const COLOR_BACKGROUND = pygame.Color(0, 0, 0)
+const _COLOR_TEXT_BG     : Color = Color::RGBA(0x0, 0x0, 0x0, 0x0);
-const UPDATE_INTERVAL_SECONDS: u32 = 62;
+const TEXT_SIZE: f32 = 160.0;  // Size of the font in pixels
-const TEXT_SIZE: u32 = 160;  // Size of the font in pixels
 
 // Offsets of each part within a line
 const XOFFSET_ROUTE: u32 = 24;
@@ -22,7 +21,6 @@ const XOFFSET_DESTINATION: u32 = 300;
 const XOFFSEET_TIME_LEFT: u32 = 1606;
 const INTER_LINE_OVERLAP: u32 = 15; 
 
-
 impl Screen<'_> {
 
     pub fn get_context(&self) -> &Sdl {
@@ -35,48 +33,88 @@ impl Screen<'_> {
         return  COLOR_LCD_RED;
     }
 
+    fn format_due_for(&self, due_in_mins: i32, departure_time: u32) -> String {
+        trace!("Due in mins: {:02}", due_in_mins);
+        if due_in_mins <= 1 {
+            return String::from("Due");
+        }
+        if due_in_mins < 60 {
+            return due_in_mins.to_string() + "min";
+        } 
+        return format!("{:02}:{:02}", (departure_time / 3600) as i32, ((departure_time / 60) % 60) as i32);
+    }
+
 
     pub fn update_information(&mut self, display_data: &DisplayData) {
+        let local_time = Local::now();
+        let seconds_since_midnight = local_time.num_seconds_from_midnight();
+
         self.do_clear();
 
-        // TODO: Add header
+        // Print status first
+        self.color = COLOR_LCD_AMBER;
+        if display_data.status.is_some() {
+            // If the update has some information text, show it
+            self.do_print_at(5, display_data.status.as_ref().unwrap(), 0);
+        } else {
+            // Display date and time otherwise
+            self.do_print_at(5, &format!("Current time: {:02}/{:02}/{:4} {:02}:{:02}",
+            local_time.day(), local_time.month(), local_time.year(),
+            local_time.hour(), local_time.minute()
+        ).to_string(), 0);
+        }
 
-        let num_arrivals: i32 = min(if display_data.status.is_some() {LINE_COUNT - 1} else {LINE_COUNT}, display_data.lines.len().try_into().unwrap());
+        // Then data lines from the bottom
-        for line in 0..num_arrivals {
+        let num_arrivals: i32 = min(LINE_COUNT, display_data.lines.len() as i32);
+        for index in 0..num_arrivals {
+            let line: u32 = ((num_arrivals - 1) - index) as u32;
             // Compose a line of text with all the information 
             let entry = display_data.lines.get(line as usize).unwrap();
-            let line: u32 = (line + 1).try_into().unwrap();
+            let due_in_mins = ((entry.departure_time - seconds_since_midnight) / 60) as i32;
-            let due_in_mins = entry.due_in as i32;
+            let due_color: Color = self.color_for(due_in_mins);
-            let arrival_color: Color = self.color_for(due_in_mins);
+            let due_text = self.format_due_for(due_in_mins, entry.departure_time);
 
             self.color = COLOR_LCD_AMBER;
             self.do_print_at(line, &entry.route, XOFFSET_ROUTE);
             self.do_print_at(line, &entry.destination, XOFFSET_DESTINATION);
-            self.color = arrival_color;
+            self.color = due_color;
-            self.do_print_at(line, &due_in_mins.to_string(), XOFFSEET_TIME_LEFT);
+            self.do_print_at(line, &due_text, XOFFSEET_TIME_LEFT);
         };
-
-        if display_data.status.is_some() {
-            self.do_print_at(5, display_data.status.as_ref().unwrap(), 0);
-        }
         self.do_update();
     }
 
 
-    pub fn print(&mut self, line: u32, text: &str) {
+    pub fn _print(&mut self, line: u32, text: &str) {
         self.do_print_at(line, text, 0);
         self.do_update();
     }
 
 
-    fn do_print_at(&mut self, line: u32, text: &str, left: u32) -> u32 {
+    fn do_print_at(&mut self, line: u32, text: &str, left: u32) {
-        let rendered_text = self.font.render(text).solid(self.color).unwrap();
+        if  text.len() == 0 {
+            warn!("do_print_at called with a 0-length string");
+            return;  
+        }
+
+        let render_result = self.font.render(text).lcd(self.color, COLOR_BACKGROUND);
+
+        if render_result.is_err() {
+            error!("Error rendering text \"{}\": {:#?}", text, render_result.err());
+            return;
+        }
+
+        let rendered_text = render_result.unwrap();
         let texture_creator = self.canvas.texture_creator();
-        let texture = rendered_text.as_texture(&texture_creator).unwrap();
+        let texture = rendered_text.as_texture(&texture_creator);
-        let _= self.canvas.copy(&texture, 
+
+        if texture.is_err() {
+            error!("Error creating texture from rendered text: {:#?}", texture.err());
+            return;
+        }
+
+        let _= self.canvas.copy(&texture.unwrap(), 
             Rect::new(0, 0, rendered_text.width(), rendered_text.height()), 
             Rect::new(left.try_into().unwrap(), (line * (rendered_text.height() - INTER_LINE_OVERLAP)).try_into().unwrap(), rendered_text.width(), rendered_text.height()));
-        return left + rendered_text.width();
     }
 
 
@@ -92,16 +130,16 @@ impl Screen<'_> {
 
 
     fn do_clear(&mut self) {
-        self.canvas.set_draw_color(Color::BLACK);
+        self.canvas.set_draw_color(COLOR_BACKGROUND);
         self.canvas.clear();
     }
 
     /// Initialize video, allocate buffers and load fonts
     /// Based on https://github.com/vhspace/sdl3-rs/blob/master/examples/ttf-demo.rs
-    pub fn init(prefs: &Prefs) -> Screen<'_> {
+    pub fn init(prefs: &Prefs) -> Result<Screen<'_>, Error> {
         // Initialize the screen   
         let sdl_context = sdl3::init().unwrap();
-        let video_subsys = sdl_context.video().unwrap();
+        let video_subsys = sdl_context.video()?;
 
         let window = video_subsys
         .window("Dublin Bus", prefs.screen_width, prefs.screen_height)
@@ -112,8 +150,8 @@ impl Screen<'_> {
 
         // Load font
         let ttf_context = sdl3::ttf::init().unwrap();
-        let font = ttf_context.load_font(&prefs.font_path, 128.0).unwrap();
+        let font = ttf_context.load_font(&prefs.font_path, TEXT_SIZE)?;
-
+        
         let mut screen: Screen = Screen {
             canvas:  Box::new(window.into_canvas()), 
             font: Box::new(font),
@@ -122,6 +160,6 @@ impl Screen<'_> {
         };
 
         screen.clear();
-        return screen;
+        return Ok(screen);
     }
 }

src/renderer/structs.rs

@@ -1,5 +1,5 @@
 use sdl3::{Sdl, pixels::Color, render::Canvas, ttf::Font, video::Window};
-
+use serde::{Serialize, Deserialize};
 
 pub struct Screen<'a> {
     pub(crate) canvas: Box<Canvas<Window>>,
@@ -8,9 +8,16 @@ pub struct Screen<'a> {
     pub(crate) context: Box<Sdl>
 }
 
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
 pub struct Prefs {
+
+    #[serde(rename = "font-path")]
     pub font_path: String,
+
+    #[serde(rename = "width")]
     pub screen_width: u32,
+
+    #[serde(rename = "height")]
     pub screen_height: u32,
 }
 
@@ -18,7 +25,7 @@ pub struct Prefs {
 pub struct DisplayEntry {
     pub route: String,
     pub destination: String,
-    pub due_in: i64,
+    pub departure_time: u32,
 }
 
 pub struct DisplayData {