diff --git a/lib/bs412.c b/lib/bs412.c
index 5511ccd..b4d8fbf 100644
--- a/lib/bs412.c
+++ b/lib/bs412.c
@@ -17,9 +17,11 @@ void init_modulation_power_measure(MPXPowerMeasurement* mpx, int sample_rate) {
 float measure_mpx(MPXPowerMeasurement* mpx, int deviation) {
 	mpx->sample += deviation;
 
-	float avg_deviation = mpx->sample/mpx->i;
+	float avg_deviation = (float)mpx->sample / mpx->i;
 	float modulation_power = deviation_to_dbr(avg_deviation);
 
+	mpx->i++;
+
 	if (mpx->i >= mpx->sample_rate*60) {
 		mpx->sample = 0;
 		mpx->i = 1;