diff --git a/src/half_duplex_serial.rs b/src/half_duplex_serial.rs
index 4d150fb..6ee83c4 100644
--- a/src/half_duplex_serial.rs
+++ b/src/half_duplex_serial.rs
@@ -10,10 +10,13 @@ use arduino_hal::{
         Pin, PinMode, PinOps,
     },
 };
-use avr_device::{asm::delay_cycles, interrupt};
+use avr_device::{
+    asm::delay_cycles,
+    interrupt::{self, disable, enable},
+};
 use embedded_hal::digital::{InputPin, OutputPin};
 
-use super::static_pins_impl::StaticPin;
+use super::static_pins_impl::StaticPinOps;
 use heapless::Vec;
 
 pub struct HalfDuplexSerial<P> {
@@ -50,6 +53,9 @@ where
     fn poll(&self) -> PollResult;
     fn response(&self);
 
+    fn is_low(&self) -> bool;
+    fn is_high(&self) -> bool;
+
     fn write_byte(&self, data: u8);
     fn read_byte(&self) -> ReadByteResult;
 
@@ -74,33 +80,50 @@ where
     P: PinOps + StaticPinOps,
 {
     fn poll(&self) -> PollResult {
-        let pin_pos = 1u8 << P::PIN_NUM;
-
+        P::into_output();
         P::into_input();
 
-        if P::read() & pin_pos == 0 {
+        delay_us(SERIAL_TRANSMIT_DELAY_US / 2);
+
+        if self.is_low() {
+            P::into_pull_up_input();
+
             return PollResult::Err(PollError::NotFound);
         }
 
-        delay_us(3);
+        P::into_pull_up_input();
+
+        delay_us(SERIAL_TRANSMIT_DELAY_US / 2);
+
+        if self.is_high() {
+            P::into_pull_up_input();
 
-        if P::read() & pin_pos != 0 {
             return PollResult::Err(PollError::NotReady);
         }
 
-        P::into_pullup_input();
+        while self.is_low() {}
 
         PollResult::Ok(())
     }
 
     fn response(&self) {
-        delay_us(1);
+        while self.is_low() {}
 
         P::into_output();
 
-        delay_us(4);
-        P::into_pull_up_input();
+        delay_us(SERIAL_TRANSMIT_DELAY_US);
 
+        P::into_pull_up_input();
+    }
+
+    #[inline]
+    fn is_low(&self) -> bool {
+        (P::read() & (1 << P::PIN_NUM)) == 0
+    }
+
+    #[inline]
+    fn is_high(&self) -> bool {
+        (P::read() & (1 << P::PIN_NUM)) != 0
     }
 
     fn write_byte(&self, data: u8) {
diff --git a/src/main.rs b/src/main.rs
index f33830e..613785f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,12 +4,13 @@
 #![feature(abi_avr_interrupt)]
 #![feature(asm_experimental_arch)]
 #![feature(thread_local)]
+#![allow(clippy::wrong_self_convention)]
 
 #[macro_use]
 extern crate static_pins;
 
 use arduino_hal::{
-    delay_ms, delay_us,
+    delay_ms,
     hal::{
         pins,
         port::{PD2, PD3, PD5},
@@ -30,14 +31,23 @@ use keyboard::*;
 #[allow(unused)]
 use panic_handler::*;
 
-// static mut SERIAL_BUFFER: Vec<u8, 5> = Vec::new();
-
 pub static mut SERIAL: Option<HalfDuplexSerial<PD3>> = None;
 
 static mut RX_LED: Option<Pin<Output, PD5>> = None;
 static mut POLL_INDICATOR: Option<Pin<Output, PD2>> = None;
 
-// const MODIFIER_MASK: u8 = 0xE0;
+fn error_poll_status_display(delay: u16) {
+    unsafe {
+        if let Some(poll_status) = POLL_INDICATOR.as_mut() {
+            for _ in 0..=5 {
+                delay_ms(delay);
+                poll_status.toggle();
+            }
+            poll_status.set_low();
+        }
+        delay_ms(500)
+    }
+}
 
 #[arduino_hal::entry]
 fn main() -> ! {
@@ -52,39 +62,35 @@ fn main() -> ! {
 
     let mut rx_led = pins.pd5.into_output();
     let poll_indicator = pins.pd2.into_output();
-    // let mut delay: Delay<MHz16> = Delay::new();
-
+    // let one_wire_pin = StaticPin::new(pins.pd3.into_pull_up_input());
     pins.pb0.into_output().set_low();
-
     rx_led.set_low();
 
-    let data_line = HalfDuplexSerial::new(pins.pd3.into_pull_up_input(), &dp.EXINT);
-
     unsafe {
+        SERIAL = Some(HalfDuplexSerial::new(
+            pins.pd3.into_pull_up_input(),
+            &dp.EXINT,
+        ));
         POLL_INDICATOR = Some(poll_indicator);
-        SERIAL = Some(data_line);
         RX_LED = Some(rx_led);
         enable();
+
         loop {
-            let scan = matrix.scan();
-            if scan[0].is_some() || scan[1].is_some() {
-                if let Some(data_line) = SERIAL.as_mut() {
-                    match data_line.poll() {
-                        Ok(_) => {
-                            if let Some(rx_led) = RX_LED.as_mut() {
-                                rx_led.toggle();
+            let pressed_keys = matrix.scan();
+            if pressed_keys[0].is_some() || pressed_keys[1].is_some() {
+                free(|_| {
+                    if let Some(serial) = SERIAL.as_ref() {
+                        match serial.poll() {
+                            Ok(_) => {
+                                if let Some(led) = POLL_INDICATOR.as_mut() {
+                                    led.set_high();
+                                }
                             }
+                            Err(PollError::NotFound) => error_poll_status_display(150),
+                            Err(PollError::NotReady) => error_poll_status_display(750),
                         }
-                        Err(poll_error) => match poll_error {
-                            PollError::NotFound => {
-                                // panic!("1");
-                            }
-                            PollError::NotReady => {
-                                // panic!("2");
-                            }
-                        },
                     }
-                }
+                });
             }
         }
     }
@@ -92,15 +98,10 @@ fn main() -> ! {
 
 #[avr_device::interrupt(atmega32u4)]
 unsafe fn INT3() {
-    free(|_| {
-        if let Some(serial) = SERIAL.as_ref() {
-            serial.response();
+    if let Some(serial) = SERIAL.as_ref() {
+        serial.response();
+        if let Some(led) = POLL_INDICATOR.as_mut() {
+            led.toggle();
         }
-        if let Some(poll_status) = POLL_INDICATOR.as_mut() {
-            poll_status.toggle();
-        }
-        // if let Some(rx_led) = RX_LED.as_mut() {
-        //     rx_led.toggle();
-        // }
-    })
+    }
 }