diff --git a/src/main.rs b/src/main.rs
index ee15711..792e46b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -39,7 +39,11 @@ pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_GENERIC_03H;
 /// if your board has a different frequency
 const XTAL_FREQ_HZ: u32 = 12_000_000u32;
 
+// ADC readings at various temps (calibration)
+// we linearize between these points,
+// so more points can help maximize accuracy
 const ZERO_DEG_C: u16 = 740;
+const TWENTY_FIVE_C: u16 = 1750;
 const SIXTY_C: u16 = 3200;
 
 /// Entry point to our bare-metal application.
@@ -95,18 +99,26 @@ fn main() -> ! {
 
     loop {
         led_pin.set_high().unwrap();
-        timer.delay_ms(200);
+        timer.delay_ms(300);
         led_pin.set_low().unwrap();
-        timer.delay_ms(200);
+        timer.delay_ms(300);
         let adc_val = adc.read(&mut adc_pin).unwrap();
         println!("ADC {=u16}, samp {=u16}", adc_val, test_val);
-        
-        let mut deg = adc_val.saturating_sub(ZERO_DEG_C) as f32;
 
-        deg = (deg * 60.) / (SIXTY_C - ZERO_DEG_C) as f32;
+        let deg = match adc_val {
+            ..ZERO_DEG_C => 0f32,
+            ZERO_DEG_C..=TWENTY_FIVE_C => {
+                let d = (adc_val - ZERO_DEG_C) as f32;
+                (d * 25.) / (TWENTY_FIVE_C - ZERO_DEG_C) as f32
+            }
+            _ => {
+                let d = (adc_val - TWENTY_FIVE_C) as f32;
+                25f32 + (d * 35.) / (SIXTY_C - TWENTY_FIVE_C) as f32
+            }
+        };
 
-        let deg = (deg * 100.) as u32;
-        let deg = (deg as f32) / 100.;
+        let deg = (deg * 10.) as u32;
+        let deg = (deg as f32) / 10.;
 
         println!("Deg? {=f32}", deg);