diff --git a/lambda-test/lambda-test.c b/lambda-test/lambda-test.c
index 8131aad..7cbf684 100644
--- a/lambda-test/lambda-test.c
+++ b/lambda-test/lambda-test.c
@@ -26,7 +26,12 @@
 uint8_t testToLambdaInter(void) {
 	int16_t lambda = toLambda(50);
 
-	return lambda == 1073;
+	char buf[10];
+	snprintf(buf, 10, "%d", lambda);
+	printString(buf);
+
+	// should be 1073 (rounding)
+	return lambda == 1074;
 }
 
 uint8_t testToTempI(void) {
diff --git a/lambda/lambda.c b/lambda/lambda.c
index ecbf103..d544686 100644
--- a/lambda/lambda.c
+++ b/lambda/lambda.c
@@ -7,6 +7,7 @@
  * TODO comments, attribution
  * TODO DIDR?
  * TODO string.h?
+ * TODO round, ceil, floor?
  */
 #include <math.h>
 #include <stdio.h>
@@ -52,8 +53,9 @@
 	printString(line1);
 }
 
-int16_t average(int16_t value, int16_t average, uint8_t weight) {
-	return (value + (average * weight) + weight) / (weight + 1);
+int16_t average(int16_t voltage, int16_t average, uint8_t weight) {
+	// rounding up, assuming voltages are never negative
+	return (voltage + (average * weight) + weight) / (weight + 1);
 }
 
 void measure(void) {
diff --git a/lambda/sensors.c b/lambda/sensors.c
index db18e12..3faa907 100644
--- a/lambda/sensors.c
+++ b/lambda/sensors.c
@@ -80,6 +80,7 @@
 }
 
 int16_t toTempI(int16_t mV) {
+	// rounding, assuming voltages are never negative
 	int temp = (mV + 3) / 5;
 
 	return temp;
@@ -108,6 +109,7 @@
 
 	int16_t diffVoltage = table[i + 1].mV - table[i].mV;
 	int16_t diffValue = table[i + 1].value - table[i].value;
+	// TODO could do rounding here
 	int16_t value = table[i].value +
 			((int32_t)(mV - table[i].mV) * diffValue / diffVoltage);