diff --git a/firmware/src/electrometer.rs b/firmware/src/electrometer.rs
index e005d9d..9ee58b6 100644
--- a/firmware/src/electrometer.rs
+++ b/firmware/src/electrometer.rs
@@ -4,7 +4,7 @@ pub struct Electrometer {
     range: board::ElectrometerRange,
     out_of_range_count: u8,
     ignore_count: u8,
-    ic_buffer: [f32; 512],
+    ic_buffer: f32,
     ic_buffer_count: usize,
     last_ic: Option<f32>
 }
@@ -20,7 +20,7 @@ impl Electrometer {
             range: board::ElectrometerRange::Med,
             out_of_range_count: 0,
             ignore_count: 0,
-            ic_buffer: [0.0; 512],
+            ic_buffer: 0.0,
             ic_buffer_count: 0,
             last_ic: None
         }
@@ -57,6 +57,7 @@ impl Electrometer {
 
             if new_range.is_some() {
                 self.ignore_count = 150;
+                self.ic_buffer = 0.0;
                 self.ic_buffer_count = 0;
                 self.last_ic = None;
                 self.range = new_range.unwrap();
@@ -67,14 +68,11 @@ impl Electrometer {
                     board::ElectrometerRange::Med => board::IC_ADC_GAIN_MED,
                     board::ElectrometerRange::High => board::IC_ADC_GAIN_HIGH
                 };
-                self.ic_buffer[self.ic_buffer_count] = ((ic_sample as f32) - board::IC_ADC_OFFSET)/gain;
+                self.ic_buffer += ((ic_sample as f32) - board::IC_ADC_OFFSET)/gain;
                 self.ic_buffer_count += 1;
-                if self.ic_buffer_count == self.ic_buffer.len() {
-                    let mut ic_avg: f32 = 0.0;
-                    for ic in self.ic_buffer.iter() {
-                        ic_avg += *ic;
-                    }
-                    self.last_ic = Some(ic_avg/(self.ic_buffer.len() as f32));
+                if self.ic_buffer_count == 512 {
+                    self.last_ic = Some(self.ic_buffer/512.0);
+                    self.ic_buffer = 0.0;
                     self.ic_buffer_count = 0;
                 }
             }