diff --git a/Cargo.lock b/Cargo.lock
index 7108237..a6d1345 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2000,8 +2000,7 @@ dependencies = [
 [[package]]
 name = "scd4x"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "550fedc97e7880654aa7dc840f5eb3b2201a01aae566c4584a3601bb0086cd4c"
+source = "git+https://github.com/twokilohertz/scd4x-rs.git?branch=self-calib-tgt#3ec7b975b32ed8ec47c71ecee3711f430871bd2e"
 dependencies = [
  "embedded-hal 1.0.0",
  "log",
diff --git a/Cargo.toml b/Cargo.toml
index bc3e3b2..65fb3f2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,7 +44,7 @@ embedded-graphics = "0.8.1"
 embedded-graphics-framebuf = "0.5.0"
 
 # Peripherals
-scd4x = { version = "0.4.0", features = ["scd41"] }
+scd4x = { git = "https://github.com/twokilohertz/scd4x-rs.git", branch = "self-calib-tgt", features = ["scd41"] }
 ssd1351 = "0.5.0"
 display-interface-spi = "0.5.0"
 
diff --git a/src/sensor_task.rs b/src/sensor_task.rs
index 97f960e..d7c9199 100644
--- a/src/sensor_task.rs
+++ b/src/sensor_task.rs
@@ -8,11 +8,15 @@ use scd4x::Scd4x;
 
 use crate::{I2c0BusMutex, SENSOR_DATA_SIGNAL};
 
+const BACKGROUND_CO2_PPM: u16 = 427;
+
 /// Read CO2/temp./humidity data from the sensor
 #[embassy_executor::task]
 pub async fn sensor_read_task(i2c_bus: &'static I2c0BusMutex) {
     debug_rprintln!("Sensor read task started");
 
+    // Initialise SCD41
+
     Timer::after_millis(30).await; // SCD41 power-up delay
     let i2c_dev = I2cDevice::new(i2c_bus);
 
@@ -20,6 +24,11 @@ pub async fn sensor_read_task(i2c_bus: &'static I2c0BusMutex) {
     scd41.wake_up();
     scd41.reinit().unwrap();
 
+    // https://climate.nasa.gov/vital-signs/carbon-dioxide/?intent=121
+    scd41
+        .set_automatic_self_calibration_target(BACKGROUND_CO2_PPM)
+        .unwrap();
+
     match scd41.serial_number() {
         Ok(serial) => debug_rprintln!("[SCD41] Serial number: {}", serial),
         Err(error) => debug_rprintln!(
@@ -28,6 +37,8 @@ pub async fn sensor_read_task(i2c_bus: &'static I2c0BusMutex) {
         ),
     }
 
+    // Measurement loop
+
     scd41.start_periodic_measurement().unwrap();
 
     loop {
@@ -53,4 +64,6 @@ pub async fn sensor_read_task(i2c_bus: &'static I2c0BusMutex) {
             }
         }
     }
+
+    scd41.stop_periodic_measurement().unwrap();
 }