Initialize number of lights from environment

Cargo.toml

@@ -18,6 +18,7 @@ rppal = "0.14"
 ws2818-rgb-led-spi-driver = { path = "./lib-ws2818-rgb-led-spi-driver" }
 common = { path = "./common" }
 webui = { path = "./webui" }
+dotenv = "0.15.0"
 
 [profile.release]
 lto = true

src/main.rs

@@ -44,6 +44,9 @@ use strip::LedStrip;
 use ui::console_ui_loop;
 
 fn main() -> ProgramResult<()> {
+    // Initialize any config
+    dotenv::dotenv().ok();
+
     // Strip control transmitter and receiver
     let (strip_tx, strip_rx) = channel::<common::strip::Message>();
     let (console_strip_tx, webui_strip_tx) = (strip_tx.clone(), strip_tx);
@@ -53,7 +56,12 @@ fn main() -> ProgramResult<()> {
     make_child(message_tx.clone(), move |message_tx| -> ProgramResult<()> {
         let mut strip = LedStrip::new(strip::Config {
             // I have 89 right now, but start off with 20
-            num_lights: 89,
+            num_lights: std::env::var("NUM_LIGHTS")
+                .as_ref()
+                .map(String::as_str)
+                .unwrap_or("89")
+                .parse()
+                .unwrap(),
             // Skip 14 lights
             shift_lights: 14,
             // Scaling factor (scale 0..255)