diff --git a/USBHost_t36.h b/USBHost_t36.h
index 39217ce..cf23d17 100644
--- a/USBHost_t36.h
+++ b/USBHost_t36.h
@@ -877,12 +877,18 @@ public:
 		user_onHeartRateMonitor = f;
 	}
 	void onSpeedCadence(void (*f)(float speed, float distance, float rpm), uint32_t devid=0) {
+		profileSetup_SPDCAD(&ant.dcfg[PROFILE_SPDCAD], devid);
+		memset(&spdcad, 0, sizeof(spdcad));
 		user_onSpeedCadence = f;
 	}
 	void onSpeed(void (*f)(float speed, float distance), uint32_t devid=0) {
+		profileSetup_SPEED(&ant.dcfg[PROFILE_SPEED], devid);
+		memset(&spd, 0, sizeof(spd));
 		user_onSpeed = f;
 	}
 	void onCadence(void (*f)(float rpm), uint32_t devid=0) {
+		profileSetup_CADENCE(&ant.dcfg[PROFILE_CADENCE], devid);
+		memset(&cad, 0, sizeof(cad));
 		user_onCadence = f;
 	}
 	void setWheelCircumference(float meters) {
diff --git a/antplus.cpp b/antplus.cpp
index eaee360..d5b8537 100644
--- a/antplus.cpp
+++ b/antplus.cpp
@@ -1130,9 +1130,9 @@ void AntPlus::payload_SPDCAD(TDCONFIG *cfg, const uint8_t *data, const size_t da
 	uint16_t speedTime = data[5] | (data[6] << 8);
 	uint16_t speedCt = data[7] | (data[8] << 8);
 	if (cadenceTime == spdcad.previous.cadenceTime
-	  && cadenceCt != spdcad.previous.cadenceCt
-	  && speedTime != spdcad.previous.speedTime
-	  && speedCt != spdcad.previous.speedCt) {
+	  && cadenceCt == spdcad.previous.cadenceCt
+	  && speedTime == spdcad.previous.speedTime
+	  && speedCt == spdcad.previous.speedCt) {
 		return; // no change
 	}
 	uint16_t cadence = (60 * (cadenceCt - spdcad.previous.cadenceCt) * 1024) / (cadenceTime - spdcad.previous.cadenceTime);