diff --git a/hardware/euro-yesman/src/main.rs b/hardware/euro-yesman/src/main.rs
index ec8bd89e4e2..01e69e5716d 100644
--- a/hardware/euro-yesman/src/main.rs
+++ b/hardware/euro-yesman/src/main.rs
@@ -9,6 +9,8 @@ use stm32f1xx_hal::{delay::Delay, pac, prelude::*};
 #[allow(unused_imports)]
 use panic_halt;
 
+mod seq;
+pub use seq::{LayerSelect, SeqLayer, Sequencer};
 
 #[entry]
 fn main() -> ! {
@@ -25,19 +27,19 @@ fn main() -> ! {
 
     // Initialize the delay object with the MCU frequency
     let mut flash = dp.FLASH.constrain();
-    let clocks = rcc.cfgr.sysclk(8.mhz()).freeze(&mut flash.acr);
+    let clocks = rcc
+        .cfgr
+        .use_hse(8.mhz())
+        .sysclk(48.mhz())
+        .pclk1(24.mhz())
+        .freeze(&mut flash.acr);
     let mut delay = Delay::new(cp.SYST, clocks);
 
     // Now go blinkenlights
     loop {
         led.set_high().ok();
-        delay.delay_ms(500_u16);
-        led.set_low().ok();
         delay.delay_ms(1000_u16);
-        led.set_high().ok();
-        delay.delay_ms(250_u16);
         led.set_low().ok();
-        delay.delay_ms(125_u16);
+        delay.delay_ms(1000_u16);
     }
-    
 }
diff --git a/hardware/euro-yesman/src/seq.rs b/hardware/euro-yesman/src/seq.rs
new file mode 100644
index 00000000000..df7ec336af3
--- /dev/null
+++ b/hardware/euro-yesman/src/seq.rs
@@ -0,0 +1,66 @@
+/// Represent a single layer on the sequencer
+pub struct SeqLayer {
+    /// List of steps that are either on or off
+    steps: [bool; 16],
+    /// The length of the sequence to loop
+    length: u8,
+}
+
+impl SeqLayer {
+    /// Get the step by index, wrapping around if the index is beyond the length
+    fn step(&self, idx: u8) -> bool {
+        let nidx = idx % self.length;
+        self.steps[nidx as usize]
+    }
+
+    fn set(&mut self, idx: usize, val: bool) {
+        self.steps[idx] = val;
+    }
+}
+
+/// Indicate which layer is selected
+pub enum LayerSelect {
+    A,
+    B,
+    C,
+    D,
+}
+
+/// Main sequencer state structure
+pub struct Sequencer {
+    a: SeqLayer,
+    b: SeqLayer,
+    c: SeqLayer,
+    d: SeqLayer,
+    active_layer: LayerSelect,
+    active_step: u8,
+}
+
+impl Sequencer {
+    /// Step to the next step, wrapping around at 16
+    pub fn step(&mut self) {
+        self.active_step %= self.active_step;
+    }
+
+    /// Get the current step for all four layers
+    pub fn get(&self) -> (bool, bool, bool, bool) {
+        let i = self.active_step;
+        (
+            self.a.step(i),
+            self.b.step(i),
+            self.c.step(i),
+            self.d.step(i),
+        )
+    }
+
+    /// Edit a step of the active layer
+    pub fn edit(&mut self, idx: usize, val: bool) {
+        assert!(idx <= 16);
+        match self.active_layer {
+            LayerSelect::A => self.a.set(idx, val),
+            LayerSelect::B => self.b.set(idx, val),
+            LayerSelect::C => self.c.set(idx, val),
+            LayerSelect::D => self.d.set(idx, val),
+        }
+    }
+}