diff --git a/Cargo.toml b/Cargo.toml
index fe98eda..4a1225f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 readme = "README.md"
 
 [dependencies]
+cortex-m = "0.6.4"
 cortex-m-rt = "0.6.13"
 panic-halt = "0.2.0"
 stm32f0xx-hal = { version = "0.17.1", features = ["rt", "stm32f072"] }
diff --git a/src/main.rs b/src/main.rs
index 7a23af4..36bf549 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -21,8 +21,36 @@
 
 use cortex_m_rt::entry;
 use panic_halt as _;
+use stm32f0xx_hal::pac::Peripherals;
+use stm32f0xx_hal::prelude::*;
 
 #[entry]
 fn main() -> ! {
-    loop {}
+    let mut p = Peripherals::take().unwrap();
+
+    let mut rcc = p.RCC.configure().freeze(&mut p.FLASH);
+
+    let gpioa = p.GPIOA.split(&mut rcc);
+    let gpiob = p.GPIOB.split(&mut rcc);
+
+    let (mut led1_b, mut led1_g, mut led1_r, mut led2_g, mut led2_r, mut led2_b) = cortex_m::interrupt::free(|cs| (
+        gpioa.pa0.into_push_pull_output(cs),
+        gpioa.pa1.into_push_pull_output(cs),
+        gpioa.pa2.into_push_pull_output(cs),
+        gpiob.pb0.into_push_pull_output(cs),
+        gpiob.pb1.into_push_pull_output(cs),
+        gpiob.pb5.into_push_pull_output(cs),
+    ));
+    led1_r.set_high().ok(); //   0
+    led1_g.set_high().ok(); //   0
+    led1_b.set_low().ok();  // 255
+    // ^ blue
+    led2_r.set_high().ok(); //   0
+    led2_g.set_low().ok();  // 255
+    led2_b.set_low().ok();  // 255
+    // ^ cyan
+
+    loop {
+        cortex_m::asm::nop();
+    }
 }