diff --git a/usb-pd/src/lib.rs b/usb-pd/src/lib.rs
index 1a4c02f..1d79695 100644
--- a/usb-pd/src/lib.rs
+++ b/usb-pd/src/lib.rs
@@ -4,6 +4,7 @@ pub mod header;
 pub mod messages;
 pub mod sink;
 pub mod source;
+pub mod timers;
 pub mod token;
 
 #[derive(Clone, Copy, PartialEq, Eq)]
diff --git a/usb-pd/src/timers/mod.rs b/usb-pd/src/timers/mod.rs
new file mode 100644
index 0000000..3272c66
--- /dev/null
+++ b/usb-pd/src/timers/mod.rs
@@ -0,0 +1,189 @@
+use embassy_time::{Duration, Instant};
+
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum TimerTypes {
+    BISTContMode,
+    ChunkingNotSupported,
+    ChunkSenderRequest,
+    ChunkSenderResponse,
+    CRCReceive,
+    DataResetFail,
+    DataResetFailUFP,
+    DiscoverIdentity,
+    HardResetComplete,
+    NoResponse,
+    PSHardReset,
+    PSSourceOff,
+    PSSourceOn,
+    PSTransition,
+    SenderResponse,
+    SinkEPREnter,
+    SinkEPRKeepAlive,
+    SinkPPSPeriodic,
+    SinkRequest,
+    SinkWaitCap,
+    SourceCapability,
+    SourceEPRKeepAlive,
+    SourcePPSComm,
+    SinkTx,
+    SwapSourceStart,
+    VCONNDischarge,
+    VCONNOn,
+    VDMModeEntry,
+    VDMModeExit,
+    VDMResponse,
+}
+
+impl From<TimerTypes> for Timer {
+    fn from(ty: TimerTypes) -> Self {
+        match ty {
+            TimerTypes::BISTContMode => Self::new(ty, timer_values::tBISTContMode),
+            TimerTypes::ChunkingNotSupported => Self::new(ty, timer_values::tChunkingNotSupported),
+            TimerTypes::ChunkSenderRequest => Self::new(ty, timer_values::tChunkSenderRequest),
+            TimerTypes::ChunkSenderResponse => Self::new(ty, timer_values::tChunkSenderResponse),
+            TimerTypes::CRCReceive => Self::new(ty, timer_values::tReceive),
+            TimerTypes::DataResetFail => Self::new(ty, timer_values::tDataResetFail),
+            TimerTypes::DataResetFailUFP => Self::new(ty, timer_values::tDataResetFailUFP),
+            TimerTypes::DiscoverIdentity => Self::new(ty, timer_values::tDiscoverIdentity),
+            TimerTypes::HardResetComplete => Self::new(ty, timer_values::tHardResetComplete),
+            TimerTypes::NoResponse => Self::new(ty, timer_values::tNoResponse),
+            TimerTypes::PSHardReset => Self::new(ty, timer_values::tPSHardReset),
+            TimerTypes::PSSourceOff => Self::new(ty, timer_values::tPSSourceOffSPR),
+            TimerTypes::PSSourceOn => Self::new(ty, timer_values::tPSSourceOnSPR),
+            TimerTypes::PSTransition => Self::new(ty, timer_values::tPSTransitionSPR),
+            TimerTypes::SenderResponse => Self::new(ty, timer_values::tSenderResponse),
+            TimerTypes::SinkEPREnter => Self::new(ty, timer_values::tEnterEPR),
+            TimerTypes::SinkEPRKeepAlive => Self::new(ty, timer_values::tSinkEPRKeepAlive),
+            TimerTypes::SinkPPSPeriodic => Self::new(ty, timer_values::tPPSRequest),
+            TimerTypes::SinkRequest => Self::new(ty, timer_values::tSinkRequest),
+            TimerTypes::SinkWaitCap => Self::new(ty, timer_values::tTypeCSinkWaitCap),
+            TimerTypes::SourceCapability => Self::new(ty, timer_values::tTypeCSendSourceCap),
+            TimerTypes::SourceEPRKeepAlive => Self::new(ty, timer_values::tSourceEPRKeepAlive),
+            TimerTypes::SourcePPSComm => todo!(),
+            TimerTypes::SinkTx => todo!(),
+            TimerTypes::SwapSourceStart => todo!(),
+            TimerTypes::VCONNDischarge => todo!(),
+            TimerTypes::VCONNOn => todo!(),
+            TimerTypes::VDMModeEntry => todo!(),
+            TimerTypes::VDMModeExit => todo!(),
+            TimerTypes::VDMResponse => todo!(),
+        }
+    }
+}
+
+#[allow(dead_code)]
+pub struct Timer {
+    ty: TimerTypes,
+    start: Instant,
+    duration: Duration,
+    expires: Option<Instant>,
+}
+
+#[allow(dead_code)]
+impl Timer {
+    pub fn new(ty: TimerTypes, duration: Duration) -> Self {
+        Self {
+            ty,
+            start: Instant::now(),
+            duration,
+            expires: Some(Instant::now().checked_add(duration).unwrap()),
+        }
+    }
+
+    pub fn is_expired(&self) -> bool {
+        self.expires
+            .map_or(false, |expires| expires <= Instant::now())
+    }
+
+    pub fn reset(&mut self) {
+        self.start = Instant::now();
+        self.expires = Some(self.start.checked_add(self.duration).unwrap());
+    }
+
+    pub fn elapsed(&self) -> Duration {
+        Instant::now().duration_since(self.start)
+    }
+
+    pub fn remaining(&self) -> Option<Duration> {
+        self.expires
+            .map(|expires| expires.duration_since(Instant::now()))
+    }
+
+    pub fn ty(&self) -> &TimerTypes {
+        &self.ty
+    }
+}
+
+#[allow(non_upper_case_globals)]
+#[allow(dead_code)]
+mod timer_values {
+    use super::Duration;
+
+    const tACTemoUpdate: Duration = Duration::from_millis(500);
+    pub(crate) const tBISTContMode: Duration = Duration::from_millis(45);
+    const tBISTCarrierMode: Duration = Duration::from_millis(300);
+    const tBISTSharedTestMode: Duration = Duration::from_secs(1);
+    const tCableMessage: Duration = Duration::from_micros(750);
+    pub(crate) const tChunkingNotSupported: Duration = Duration::from_millis(45);
+    const tChunkReceiverRequest: Duration = Duration::from_millis(15);
+    const tChunkReceiverResponse: Duration = Duration::from_millis(15);
+    pub(crate) const tChunkSenderRequest: Duration = Duration::from_millis(27);
+    pub(crate) const tChunkSenderResponse: Duration = Duration::from_millis(27);
+    const tDataReset: Duration = Duration::from_millis(225);
+    pub(crate) const tDataResetFail: Duration = Duration::from_millis(350);
+    pub(crate) const tDataResetFailUFP: Duration = Duration::from_millis(500);
+    pub(crate) const tDiscoverIdentity: Duration = Duration::from_millis(45);
+    const tDRSwapHardReset: Duration = Duration::from_millis(15);
+    const tDRSwapWait: Duration = Duration::from_millis(100);
+    const tEnterUSB: Duration = Duration::from_millis(500);
+    const tEnterUSBWait: Duration = Duration::from_millis(100);
+    pub(crate) const tEnterEPR: Duration = Duration::from_millis(500);
+    const tEPRSourceCableDiscovery: Duration = Duration::from_secs(2);
+    const tFirstSourceCap: Duration = Duration::from_millis(250);
+    const tFRSwap5V: Duration = Duration::from_millis(15);
+    const tFRSwapComplete: Duration = Duration::from_millis(15);
+    const tFRSwapInit: Duration = Duration::from_millis(15);
+    const tHardReset: Duration = Duration::from_millis(5);
+    pub(crate) const tHardResetComplete: Duration = Duration::from_millis(5);
+    pub(crate) const tSourceEPRKeepAlive: Duration = Duration::from_millis(875);
+    pub(crate) const tSinkEPRKeepAlive: Duration = Duration::from_millis(375);
+    pub(crate) const tNoResponse: Duration = Duration::from_secs(5);
+    pub(crate) const tPPSRequest: Duration = Duration::from_secs(5); // Max is 10 seconds.
+    const tPPSTimeout: Duration = Duration::from_secs(13);
+    const tProtErrHardReset: Duration = Duration::from_millis(15);
+    const tProtErrSoftReset: Duration = Duration::from_millis(15);
+    const tPRSwapWait: Duration = Duration::from_millis(100);
+    pub(crate) const tPSHardReset: Duration = Duration::from_millis(30);
+    pub(crate) const tPSSourceOffSPR: Duration = Duration::from_millis(835);
+    const tPSSourceOffEPR: Duration = Duration::from_millis(1260);
+    pub(crate) const tPSSourceOnSPR: Duration = Duration::from_millis(435);
+    pub(crate) const tPSTransitionSPR: Duration = Duration::from_millis(500);
+    const tPSTransitionEPR: Duration = Duration::from_millis(925);
+    pub(crate) const tReceive: Duration = Duration::from_millis(1);
+    const tReceiverResponse: Duration = Duration::from_millis(15);
+    const tRetry: Duration = Duration::from_micros(195);
+    pub(crate) const tSenderResponse: Duration = Duration::from_millis(30);
+    const tSinkDelay: Duration = Duration::from_millis(5);
+    pub(crate) const tSinkRequest: Duration = Duration::from_millis(100);
+    const tSinkTx: Duration = Duration::from_millis(18);
+    const tSoftReset: Duration = Duration::from_millis(15);
+    const tSrcHoldsBus: Duration = Duration::from_millis(50);
+    const tSwapSinkReady: Duration = Duration::from_millis(15);
+    const tSwapSourceStart: Duration = Duration::from_millis(20);
+    const tTransmit: Duration = Duration::from_micros(195);
+    pub(crate) const tTypeCSendSourceCap: Duration = Duration::from_millis(150);
+    pub(crate) const tTypeCSinkWaitCap: Duration = Duration::from_millis(465);
+    const tVCONNSourceDischarge: Duration = Duration::from_millis(200);
+    const tVCONNSourceOff: Duration = Duration::from_millis(25);
+    const tVCONNSourceOn: Duration = Duration::from_millis(50);
+    const tVCONNSourceTimeout: Duration = Duration::from_millis(150);
+    const tVCONNSwapWait: Duration = Duration::from_millis(100);
+    const tVDMBusy: Duration = Duration::from_millis(50);
+    const tVDMEnterMode: Duration = Duration::from_millis(25);
+    const tVDMExitMode: Duration = Duration::from_millis(25);
+    const tVDMReceiverResponse: Duration = Duration::from_millis(15);
+    const tVDMSenderResponse: Duration = Duration::from_millis(27);
+    const tVDMWaitModeEntry: Duration = Duration::from_millis(45);
+    const tVDMWaitModeExit: Duration = Duration::from_millis(45);
+}