diff --git a/bluepill-rs/src/dmx.rs b/bluepill-rs/src/dmx.rs
index 8458e6c..a394e51 100644
--- a/bluepill-rs/src/dmx.rs
+++ b/bluepill-rs/src/dmx.rs
@@ -2,18 +2,20 @@ use cortex_m::singleton;
 use stm32f1xx_hal::{dma, pac, prelude::*, rcc, serial};
 
 type _TxDma = dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>;
+type _DMXUniverse<const DMX_LEN: usize> = &'static mut [u8; DMX_LEN];
+type _DMXTransfer<const DMX_LEN: usize> = dma::Transfer<dma::R, _DMXUniverse<DMX_LEN>, _TxDma>;
 
-pub struct DMXIdle {
+pub struct DMXIdle<const DMX_LEN: usize> {
     tx: Option<_TxDma>,
-    txbuffer: Option<&'static mut [u8; 512]>,
+    txbuffer: Option<_DMXUniverse<DMX_LEN>>,
 }
 
-pub enum DMX {
-    Idle(DMXIdle),
-    Busy(Option<dma::Transfer<dma::R, &'static mut [u8; 512], _TxDma>>),
+pub enum DMX<const DMX_LEN: usize = 512> {
+    Idle(DMXIdle<DMX_LEN>),
+    Busy(Option<_DMXTransfer<DMX_LEN>>),
 }
 
-impl DMX {
+impl<const DMX_LEN: usize> DMX<DMX_LEN> {
     pub fn new<PINS>(
         mut serial: serial::Serial<pac::USART1, PINS>,
         channel: dma::dma1::C4,
@@ -30,7 +32,7 @@ impl DMX {
         })
     }
 
-    pub fn send(&mut self, data: &[u8; 512]) {
+    pub fn send(&mut self, data: &[u8; DMX_LEN]) {
         if let Self::Busy(_) = self {
             self.wait();
         }
@@ -39,10 +41,10 @@ impl DMX {
             panic!("Broken DMX State!")
         };
 
-        let txbuffer = idle
-            .txbuffer
-            .take()
-            .unwrap_or_else(|| singleton!(: [u8; 512] = [0; 512]).unwrap());
+        let txbuffer = idle.txbuffer.take().unwrap_or_else(|| {
+            let foo = singleton!(: [u8; 512] = [0u8; 512]).unwrap();
+            (&mut foo[..DMX_LEN]).try_into().unwrap()
+        });
         let tx = idle.tx.take().unwrap();
 
         txbuffer.copy_from_slice(data);
diff --git a/bluepill-rs/src/main.rs b/bluepill-rs/src/main.rs
index 37f29f3..427d323 100644
--- a/bluepill-rs/src/main.rs
+++ b/bluepill-rs/src/main.rs
@@ -29,7 +29,7 @@ mod app {
 
     #[local]
     struct Local {
-        dmx: DMX,
+        dmx: DMX<512>,
         led: gpio::gpioc::PC13<gpio::Output>,
     }