diff --git a/display/src/lcd.rs b/display/src/lcd.rs
index 00af244..5256c61 100644
--- a/display/src/lcd.rs
+++ b/display/src/lcd.rs
@@ -1,3 +1,8 @@
+//! Write to a 16x2 LCD.
+//!
+//! Code mostly translated from here (an excellent project):
+//! https://github.com/Pi4J/pi4j-example-components/blob/main/src/main/java/com/pi4j/catalog/components/LcdDisplay.java
+
 use embassy_nrf::interrupt::Priority;
 use embassy_nrf::interrupt::{self, InterruptExt};
 use embassy_nrf::peripherals::{P0_03, P0_04, TWISPI0};