diff --git a/src/device/boot.rs b/src/device/boot.rs
index 24fb2dc..1d587da 100644
--- a/src/device/boot.rs
+++ b/src/device/boot.rs
@@ -1,5 +1,6 @@
 use super::{gpio, sys_timer, usb};
 use crate::laser_diode::current_sources::*;
+use crate::laser_diode::pd_mon::PdMon;
 use crate::thermostat::max1968::{MAX1968};
 use crate::thermostat::thermostat::Thermostat;
 use fugit::ExtU32;
@@ -38,7 +39,7 @@ pub fn bootup(
 
     sys_timer::setup(core_perif.SYST, clocks);
 
-    let (_eth_pins, usb, current_source_phy, max1968_phy) = gpio::setup(
+    let (_eth_pins, usb, current_source_phy, pd_mon_phy, max1968_phy) = gpio::setup(
         clocks,
         perif.TIM4,
         perif.GPIOA,
@@ -65,6 +66,9 @@ pub fn bootup(
     laser.setup();
     laser.set_current(0.1).unwrap();
 
+    let mut pd_mon = PdMon::new(pd_mon_phy, perif.ADC2);
+
+
     let tec_driver = MAX1968::new(max1968_phy, perif.ADC1);
 
     let mut thermostat = Thermostat::new(tec_driver);
diff --git a/src/device/gpio.rs b/src/device/gpio.rs
index 90380d1..e89abeb 100644
--- a/src/device/gpio.rs
+++ b/src/device/gpio.rs
@@ -1,4 +1,5 @@
 use crate::laser_diode::current_sources::*;
+use crate::laser_diode::pd_mon::PdMonPhy;
 use crate::thermostat::ad5680;
 use crate::thermostat::max1968::{Channel0, MAX1968PinSet, MAX1968Phy, PWM_FREQ_KHZ};
 use fugit::RateExtU32;
@@ -36,8 +37,8 @@ pub fn setup(
     EthernetPins,
     USB,
     CurrentSourcePhyConstruct<CurrentSourcePhyCh0>,
+    PdMonPhy,
     MAX1968Phy<Channel0>,
-    // photo_diode_phy,
     // thermostat_phy
 ) {
     let gpioa = gpioa.split();
@@ -86,6 +87,10 @@ pub fn setup(
         current_source_short: gpioa.pa4.into_push_pull_output(),
     };
 
+    let pd_mon_phy = PdMonPhy {
+        ch0_pin: gpioa.pa3.into_analog()
+    };
+
     let pwm_chs = (
         gpiob.pb6.into_alternate(),
         gpiob.pb7.into_alternate(),
@@ -121,5 +126,5 @@ pub fn setup(
         max_i_neg: max_i_neg0,
     });
 
-    (eth_pins, usb, current_source_phy, max1968_phy)
+    (eth_pins, usb, current_source_phy, pd_mon_phy, max1968_phy)
 }
diff --git a/src/laser_diode/current_sources.rs b/src/laser_diode/current_sources.rs
index 143de88..f329050 100644
--- a/src/laser_diode/current_sources.rs
+++ b/src/laser_diode/current_sources.rs
@@ -1,12 +1,13 @@
 use stm32f4xx_hal::{
-    gpio::{gpioa::*, gpiob::*, gpiod::*, Alternate, Output, PushPull, PD9},
+    gpio::{gpioa::*, gpiob::*, gpiod::*, Alternate, Output, PushPull, Analog, PD9},
     hal::{blocking::spi::Write, digital::v2::OutputPin},
     pac::SPI2,
     spi::{NoMiso, Spi, TransferModeNormal},
 };
 
 use crate::device::sys_timer::sleep;
-pub trait CurrentSourcePhy {
+pub trait ChannelPins {
+    type PdMonPin;
     type CurrentSourceLdoEn: OutputPin;
     type CurrentSourceShort: OutputPin;
     type Max5719Load: OutputPin;
@@ -14,7 +15,7 @@ pub trait CurrentSourcePhy {
     type Max5719Spi: Write<u8>;
 }
 
-pub struct CurrentSourcePhyConstruct<C: CurrentSourcePhy> {
+pub struct CurrentSourcePhyConstruct<C: ChannelPins> {
     pub max5719_spi: C::Max5719Spi,
     pub max5719_load: C::Max5719Load,
     pub max5719_cs: C::Max5719Cs,
@@ -24,14 +25,15 @@ pub struct CurrentSourcePhyConstruct<C: CurrentSourcePhy> {
 pub struct CurrentSourceSettings {
     pub output_current: f32,
 }
-pub struct CurrentSource<C: CurrentSourcePhy> {
+pub struct CurrentSource<C: ChannelPins> {
     pub phy: CurrentSourcePhyConstruct<C>,
     pub setting: CurrentSourceSettings,
 }
 
-pub struct CurrentSourcePhyCh0;
+pub struct Channel0;
 
-impl CurrentSourcePhy for CurrentSourcePhyCh0 {
+impl ChannelPins for Channel0 {
+    type PdMonPin = PA3<Analog>;
     type CurrentSourceLdoEn = PD9<Output<PushPull>>;
     type CurrentSourceShort = PA4<Output<PushPull>>;
     type Max5719Load = PB14<Output<PushPull>>;
@@ -40,7 +42,7 @@ impl CurrentSourcePhy for CurrentSourcePhyCh0 {
         Spi<SPI2, (PB10<Alternate<5>>, NoMiso, PB15<Alternate<5>>), TransferModeNormal>;
 }
 
-impl<C: CurrentSourcePhy> CurrentSource<C> {
+impl<C: ChannelPins> CurrentSource<C> {
     pub fn setup(&mut self) {
         let _ = self.phy.max5719_load.set_high();
         let _ = self.phy.max5719_cs.set_high();
@@ -53,7 +55,7 @@ impl<C: CurrentSourcePhy> CurrentSource<C> {
     pub fn set_current(
         &mut self,
         current: f32,
-    ) -> Result<(), <<C as CurrentSourcePhy>::Max5719Spi as Write<u8>>::Error> {
+    ) -> Result<(), <<C as ChannelPins>::Max5719Spi as Write<u8>>::Error> {
         let _ = self.phy.max5719_load.set_high();
         let _ = self.phy.max5719_cs.set_low();
         self.setting.output_current = current * 10.0 / 0.75;
diff --git a/src/laser_diode/mod.rs b/src/laser_diode/mod.rs
index e15efa5..c49bc5f 100644
--- a/src/laser_diode/mod.rs
+++ b/src/laser_diode/mod.rs
@@ -1 +1 @@
-pub mod current_sources;
+pub mod current_sources;
\ No newline at end of file
diff --git a/src/thermostat/max1968.rs b/src/thermostat/max1968.rs
index 2b527df..4581d16 100644
--- a/src/thermostat/max1968.rs
+++ b/src/thermostat/max1968.rs
@@ -2,7 +2,7 @@ use core::marker::PhantomData;
 use core::u16;
 
 use crate::thermostat::ad5680;
-use crate::thermostat::thermostat::{DAC_OUT_V_MAX, TEC_VSEC_BIAS_V};
+use crate::thermostat::thermostat::Settings;
 
 use fugit::KilohertzU32;
 use stm32f4xx_hal::{
@@ -59,8 +59,6 @@ impl ChannelPins for Channel0 {
 }
 
 pub struct MAX1968Phy<C: ChannelPins> {
-    // state
-    pub center_pt: ElectricPotential,
     pub dac: ad5680::Dac<C::DacSpi, C::DacSync>,
     pub shdn: C::ShdnPin,
     pub vref_pin: C::VRefPin,
@@ -86,12 +84,6 @@ pub struct MAX1968PinSet<C: ChannelPins> {
 
 type DacSpi = Spi<SPI1, (PB3<Alternate<5>>, NoMiso, PB5<Alternate<5>>), TransferModeNormal>;
 type DacSync = PB4<Output<PushPull>>;
-pub struct MaxAdcPins {
-    pub dac_vfb: PC0<Analog>,
-    pub vref: PA6<Analog>,
-    pub itec: PB1<Analog>,
-    pub vtec: PB0<Analog>,
-}
 
 pub struct MAX1968 {
     // settings
@@ -115,7 +107,6 @@ pub enum AdcReadTarget {
 impl<C: ChannelPins> MAX1968Phy<C> {
     pub fn new(pins: MAX1968PinSet<C>) -> Self {
         MAX1968Phy {
-            center_pt: ElectricPotential::new::<volt>(1.5),
             dac: pins.dac,
             shdn: pins.shdn,
             vref_pin: pins.vref_pin,
@@ -143,27 +134,17 @@ impl MAX1968 {
         }
     }
 
-    // pub fn setup(&mut self) {
-    //     self.power_down();
-
-    //     let vref = self.adc_read(AdcReadTarget::VREF, 2048);
-    //     self.set_center_point(vref);
-    // }
-
     pub fn power_down(&mut self) {
-        let _ = self.phy.shdn.set_low();
+        self.phy.shdn.set_low();
     }
 
     pub fn power_up(&mut self) {
-        let _ = self.phy.shdn.set_high();
+        self.phy.shdn.set_high();
     }
 
-    pub fn set_center_point(&mut self, value: ElectricPotential) {
-        self.phy.center_pt = value;
-    }
 
-    pub fn set_dac(&mut self, voltage: ElectricPotential) -> ElectricPotential {
-        let value = ((voltage / ElectricPotential::new::<volt>(DAC_OUT_V_MAX)).get::<ratio>()
+    pub fn set_dac(&mut self, voltage: ElectricPotential, dac_out_v_max: ElectricPotential) -> ElectricPotential {
+        let value = ((voltage / dac_out_v_max).get::<ratio>()
             * (ad5680::MAX_VALUE as f64)) as u32;
         self.phy.dac.set(value).unwrap();
         // TODO: Store the set-ed DAC Voltage Value
@@ -216,25 +197,6 @@ impl MAX1968 {
         ElectricPotential::new::<millivolt>(mv as f64)
     }
 
-    pub fn get_vref(&mut self) -> ElectricPotential {
-        self.adc_read(AdcReadTarget::VREF, 16)
-    }
-
-    pub fn get_dac_vfb(&mut self) -> ElectricPotential {
-        self.adc_read(AdcReadTarget:: DacVfb, 16)
-    }
-
-    pub fn get_tec_i(&mut self) -> ElectricCurrent {
-        (self.adc_read(AdcReadTarget::ITec, 1) - self.phy.center_pt)
-            / ElectricalResistance::new::<ohm>(0.4)
-    }
-
-    pub fn get_tec_v(&mut self) -> ElectricPotential {
-        // Fixme: Rev0_2 has Analog Input Polarity Reversed
-        //  Remove the -ve sign for Rev0_3
-        -(self.adc_read(AdcReadTarget::VTec, 1) - TEC_VSEC_BIAS_V) * 4.0
-    }
-
     pub fn set_pwm(&mut self, pwm_pin: PwmPinsEnum, duty: f64, max_duty: f64) -> f64 {
         fn set<P: hal::PwmPin<Duty = u16>>(pin: &mut P, duty: f64) -> f64 {
             let max = pin.get_max_duty();
diff --git a/src/thermostat/thermostat.rs b/src/thermostat/thermostat.rs
index eb61f01..7026269 100644
--- a/src/thermostat/thermostat.rs
+++ b/src/thermostat/thermostat.rs
@@ -3,13 +3,15 @@ use crate::sys_timer;
 use crate::thermostat::ad5680;
 use crate::thermostat::max1968::{MAX1968, AdcReadTarget, PwmPinsEnum};
 use log::info;
+use miniconf::serde::de::value;
 use uom::si::{
     electric_current::ampere,
-    electric_potential::{millivolt, volt},
+    electric_potential::volt,
     electrical_resistance::ohm,
     f64::{ElectricCurrent, ElectricPotential, ElectricalResistance},
     ratio::ratio,
 };
+use miniconf::Miniconf;
 
 pub const R_SENSE: ElectricalResistance = ElectricalResistance {
     dimension: PhantomData,
@@ -17,72 +19,99 @@ pub const R_SENSE: ElectricalResistance = ElectricalResistance {
     value: 0.05,
 };
 
-// Rev 0_2: DAC Chip connects 3V3 reference voltage and thus provide 0-3.3V output range
-// TODO: Rev 0_3: DAC Chip connects 3V3 reference voltage,
-//      which is then passed through a resistor divider to provide 0-3V output range
-pub const DAC_OUT_V_MAX: f64 = 3.3;
-pub const TEC_VSEC_BIAS_V: ElectricPotential = ElectricPotential {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 1.65,
-};
+#[derive(Clone, Debug, Miniconf)]
+pub struct Settings {
+    pub center_pt: ElectricPotential,
+    pub max_v_set: ElectricPotential,
+    pub max_i_pos_set: ElectricCurrent,
+    pub max_i_neg_set: ElectricCurrent,
+    pub i_set: ElectricCurrent,
+}
 
-// Kirdy Design Specs:
-// MaxV = 5.0V
-// MAX Current = +- 1.0A
-const MAX_V_DUTY_TO_CURRENT_RATE: ElectricPotential = ElectricPotential {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 4.0 * 3.3,
-};
-pub const MAX_V_MAX: ElectricPotential = ElectricPotential {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 5.0,
-};
-const MAX_V_DUTY_MAX: f64 = MAX_V_MAX.value / MAX_V_DUTY_TO_CURRENT_RATE.value;
-const MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE: ElectricCurrent = ElectricCurrent {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 1.0 / (10.0 * R_SENSE.value / 3.3),
-};
-pub const MAX_I_POS_CURRENT: ElectricCurrent = ElectricCurrent {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 1.0,
-};
-pub const MAX_I_NEG_CURRENT: ElectricCurrent = ElectricCurrent {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 1.0,
-};
-// .get::<ratio>() is not implemented for const
-const MAX_I_POS_DUTY_MAX: f64 = MAX_I_POS_CURRENT.value / MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE.value;
-const MAX_I_NEG_DUTY_MAX: f64 = MAX_I_NEG_CURRENT.value / MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE.value;
+impl Settings{
+    // FixMe: Rev0_2 is 3.3V max while Rev0_3 is 3.0V max 
+    pub const DAC_OUT_V_MAX: ElectricPotential = ElectricPotential {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 3.3,
+    };
+    pub const TEC_VSEC_BIAS_V: ElectricPotential = ElectricPotential {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 1.65,
+    };
+    
+    // Kirdy Design Specs:
+    // MaxV = 5.0V
+    // MAX Current = +- 1.0A
+    const MAX_V_DUTY_TO_CURRENT_RATE: ElectricPotential = ElectricPotential {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 4.0 * 3.3,
+    };
+    pub const MAX_V_MAX: ElectricPotential = ElectricPotential {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 5.0,
+    };
+    const MAX_V_DUTY_MAX: f64 = Settings::MAX_V_MAX.value / Settings::MAX_V_DUTY_TO_CURRENT_RATE.value;
+    const MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE: ElectricCurrent = ElectricCurrent {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 1.0 / (10.0 * R_SENSE.value / 3.3),
+    };
+    pub const MAX_I_POS_CURRENT: ElectricCurrent = ElectricCurrent {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 1.0,
+    };
+    pub const MAX_I_NEG_CURRENT: ElectricCurrent = ElectricCurrent {
+        dimension: PhantomData,
+        units: PhantomData,
+        value: 1.0,
+    };
+    // .get::<ratio>() is not implemented for const
+    const MAX_I_POS_DUTY_MAX: f64 = Settings::MAX_I_POS_CURRENT.value / Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE.value;
+    const MAX_I_NEG_DUTY_MAX: f64 = Settings::MAX_I_NEG_CURRENT.value / Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE.value;
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Self {
+            center_pt: ElectricPotential::new::<volt>(1.5),
+            max_v_set: ElectricPotential::new::<volt>(5.0),
+            max_i_pos_set: ElectricCurrent::new::<ampere>(1.0),
+            max_i_neg_set: ElectricCurrent::new::<ampere>(1.0),
+            i_set: ElectricCurrent::new::<ampere>(0.0),
+        }
+    }
+}
 
 pub struct Thermostat {
     max1968: MAX1968,
+    pub tec_setting: Settings,
     // TADC
 }
 
 impl Thermostat{
     pub fn new (max1968: MAX1968) -> Self {
         Thermostat{
-            max1968
+            max1968: max1968,
+            tec_setting: Settings::default(),
         }
     }
     pub fn setup(&mut self) {
-        self.power_down();
+        self.power_up();
+
+        self.tec_setting = Settings::default();
 
         self.calibrate_dac_value();
 
-        self.set_i(ElectricCurrent::new::<ampere>(0.0));
+        self.set_i(self.tec_setting.i_set);
 
-        self.set_max_v(ElectricPotential::new::<volt>(5.0));
-        self.set_max_i_pos(ElectricCurrent::new::<ampere>(1.0));
-        self.set_max_i_neg(ElectricCurrent::new::<ampere>(1.0));
-
-        self.max1968.power_up();
+        self.set_max_v(self.tec_setting.max_v_set);
+        self.set_max_i_pos(self.tec_setting.max_i_pos_set);
+        self.set_max_i_neg(self.tec_setting.max_i_neg_set);
     }
 
     pub fn power_up(&mut self){
@@ -93,29 +122,56 @@ impl Thermostat{
         self.max1968.power_down();
     }
 
+    fn set_center_pt(&mut self, value: ElectricPotential){
+        info!("set center pt: {:?}", value);
+        self.tec_setting.center_pt = value;
+    }
+
     pub fn set_i(&mut self, i_tec: ElectricCurrent) -> ElectricCurrent {
-        let voltage = i_tec * 10.0 * R_SENSE + self.max1968.phy.center_pt;
-        let voltage = self.max1968.set_dac(voltage);
-        let i_tec = (voltage - self.max1968.phy.center_pt) / (10.0 * R_SENSE);
-        i_tec
+        let voltage = i_tec * 10.0 * R_SENSE + self.tec_setting.center_pt;
+        let voltage = self.max1968.set_dac(voltage, Settings::DAC_OUT_V_MAX);
+        self.tec_setting.i_set = (voltage - self.tec_setting.center_pt) / (10.0 * R_SENSE);
+        self.tec_setting.i_set
     }
 
     pub fn set_max_v(&mut self, max_v: ElectricPotential) -> ElectricPotential {
-        let duty = (max_v / MAX_V_DUTY_TO_CURRENT_RATE).get::<ratio>();
-        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxV, duty, MAX_V_DUTY_MAX);
-        duty * MAX_V_DUTY_TO_CURRENT_RATE
+        let duty = (max_v / Settings::MAX_V_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxV, duty, Settings::MAX_V_DUTY_MAX);
+        self.tec_setting.max_v_set = duty * Settings::MAX_V_DUTY_TO_CURRENT_RATE;
+        self.tec_setting.max_v_set
     }
 
     pub fn set_max_i_pos(&mut self, max_i_pos: ElectricCurrent) -> ElectricCurrent {
-        let duty = (max_i_pos / MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE).get::<ratio>();
-        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxPosI, duty, MAX_I_POS_DUTY_MAX);
-        duty * MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE
+        let duty = (max_i_pos / Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxPosI, duty, Settings::MAX_I_POS_DUTY_MAX);
+        self.tec_setting.max_i_pos_set = duty * Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE;
+        self.tec_setting.max_i_pos_set
     }
 
     pub fn set_max_i_neg(&mut self, max_i_neg: ElectricCurrent) -> ElectricCurrent {
-        let duty = (max_i_neg / MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE).get::<ratio>();
-        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxNegI, duty, MAX_I_NEG_DUTY_MAX);
-        duty * MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE
+        let duty = (max_i_neg / Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let duty = self.max1968.set_pwm(PwmPinsEnum::MaxNegI, duty, Settings::MAX_I_NEG_DUTY_MAX);
+        self.tec_setting.max_i_neg_set = duty * Settings::MAX_I_POS_NEG_DUTY_TO_CURRENT_RATE;
+        self.tec_setting.max_i_neg_set
+    }
+
+    pub fn get_dac_vfb(&mut self) -> ElectricPotential {
+        self.max1968.adc_read(AdcReadTarget::DacVfb, 16)
+    }
+
+    pub fn get_vref(&mut self) -> ElectricPotential {
+        self.max1968.adc_read(AdcReadTarget::VREF, 16)
+    }
+
+    pub fn get_tec_i(&mut self) -> ElectricCurrent {
+        let vref = self.get_vref();
+        (self.max1968.adc_read(AdcReadTarget::ITec, 16) - vref) / ElectricalResistance::new::<ohm>(0.4)
+    }
+
+    pub fn get_tec_v(&mut self) -> ElectricPotential {
+        // Fixme: Rev0_2 has Analog Input Polarity Reversed
+        //  Remove the -ve sign for Rev0_3
+        -(self.max1968.adc_read(AdcReadTarget::VTec, 16) - Settings::TEC_VSEC_BIAS_V) * 4.0
     }
 
     /// Calibrates the DAC output to match vref of the MAX driver to reduce zero-current offset of the MAX driver output.
@@ -135,19 +191,14 @@ impl Thermostat{
     /// VREF measurement can introduce significant noise at the current output, degrading the stabilily performance of the
     /// thermostat. 
     pub fn calibrate_dac_value(&mut self) {
-        let samples = 50;
-        let mut target_voltage = ElectricPotential::new::<volt>(0.0);
-        for _ in 0..samples {
-            target_voltage = target_voltage + self.max1968.adc_read(AdcReadTarget::VREF, 1);
-        }
-        target_voltage = target_voltage / samples as f64;
+        let target_voltage = self.max1968.adc_read(AdcReadTarget::VREF, 64);
         let mut start_value = 1;
         let mut best_error = ElectricPotential::new::<volt>(100.0);
         for step in (0..18).rev() {
             info!("Step: {} Calibrating", step);
             let mut prev_value = start_value;
             for value in (start_value..=ad5680::MAX_VALUE).step_by(1 << step) {
-                //info!("Calibrating");
+                info!("Calibrating: Value: {:?}", value);
                 self.max1968.phy.dac.set(value).unwrap();
                 sys_timer::sleep(5);
 
@@ -159,12 +210,13 @@ impl Thermostat{
                     best_error = error;
                     start_value = prev_value;
 
-                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * ElectricPotential::new::<volt>(DAC_OUT_V_MAX);
-                    self.max1968.set_center_point(vref);
+                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * Settings::DAC_OUT_V_MAX;
+                    self.set_center_pt(vref);
                 }
                 prev_value = value;
             }
         }
+        info!("Best Error: {:?}", best_error);
     }
     
 }
\ No newline at end of file