diff --git a/test_LED5_hard_interrupt/Cargo.toml b/test_LED5_hard_interrupt/Cargo.toml
index 068ef44..872abb5 100644
--- a/test_LED5_hard_interrupt/Cargo.toml
+++ b/test_LED5_hard_interrupt/Cargo.toml
@@ -10,11 +10,7 @@ path = "./src/bin/main.rs"
 
 [dependencies]
 esp-bootloader-esp-idf = { version = "0.2.0", features = ["esp32"] }
-esp-hal = { version = "=1.0.0-rc.0", features = [
-  "esp32",
-  "log-04",
-  "unstable",
-] }
+esp-hal = { version = "=1.0.0-rc.0", features = ["esp32", "log-04", "rt", "unstable"] }
 log = "0.4.27"
 embedded-io = "0.6.1"
 embedded-io-async = "0.6.1"
diff --git a/test_LED5_hard_interrupt/src/bin/main.rs b/test_LED5_hard_interrupt/src/bin/main.rs
index 106674d..25435e3 100644
--- a/test_LED5_hard_interrupt/src/bin/main.rs
+++ b/test_LED5_hard_interrupt/src/bin/main.rs
@@ -12,9 +12,12 @@ use esp_hal::{
     clock::CpuClock,
     gpio::{Level, Output, OutputConfig},
     timer::Timer,
+    interrupt,
+    peripherals,
     timer::timg::TimerGroup,
     time::Duration,
 };
+use esp_hal::handler;
 use log::info;
 
 extern crate alloc;
@@ -23,6 +26,8 @@ extern crate alloc;
 // For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
 esp_bootloader_esp_idf::esp_app_desc!();
 
+static mut INTERRUPT_FIRED: bool = false;
+
 #[esp_hal_embassy::main]
 async fn main(spawner: Spawner) {
     esp_println::logger::init_logger_from_env();
@@ -32,35 +37,53 @@ async fn main(spawner: Spawner) {
     
     esp_alloc::heap_allocator!(size: 64 * 1024);
     
-    let timer_group1 = TimerGroup::new(peripherals.TIMG1);
-    let timer0 = timer_group1.timer0;
+    let mut timer_group1 = TimerGroup::new(peripherals.TIMG1);
+    let mut timer0 = timer_group1.timer0;
+
+    // make it periodic, 1 s per tick, enable interrupt
+    timer0.enable_interrupt(true);
+    timer0.enable_auto_reload(true);
+    timer0.load_value(Duration::from_secs(1)).unwrap();
+    timer0.start();
+
+    // enable NVIC entry for this timer
+    unsafe {
+        interrupt::enable(
+            peripherals::Interrupt::TG1_T0_LEVEL,
+            interrupt::Priority::Priority2, // medium priority for now
+        )
+        .unwrap();
+    }
 
     // Initialize GPIO4 as output (starts LOW)
     let mut gpio4 = Output::new(peripherals.GPIO4, Level::Low, OutputConfig::default());
     
     info!("Embassy initialized!");
     loop {
-        gpio4.set_high();
-        info!("GPIO4 ON");
 
-        // Start timer for 1 second and block until done
-        let duration = Duration::from_secs(1);
-        timer0.load_value(duration).unwrap();
-        timer0.start();
-        info!("{:?}", duration);
+        let mut counter = 0;
+        while counter < 10000000 {
+            counter += 1;
+        }
 
-        // Wait until timer completes
-        while !timer0.is_interrupt_set() {}
-        timer0.clear_interrupt();
-
-        gpio4.set_low();
-        info!("GPIO4 OFF");
-
-        // Start timer for 1 second and block until done
-        timer0.load_value(duration).unwrap();
-        timer0.start();
-
-        while !timer0.is_interrupt_set() {}
-        timer0.clear_interrupt();
+        unsafe {
+            if INTERRUPT_FIRED {
+                info!("Timer interrupt fired!");
+                INTERRUPT_FIRED = false;
+            }
+        }
     }
 }
+
+#[handler]
+fn TG1_T0_LEVEL() {
+    // Clear the interrupt
+    critical_section::with(|_cs| {
+        unsafe {
+            let mut tg1 = TimerGroup::new(peripherals::TIMG1::steal());
+            tg1.timer0.clear_interrupt();
+
+            INTERRUPT_FIRED = true;
+        }
+    });
+}