updates to how calculations work when event counter doesn't change

ant/powerProfile.go

@@ -66,13 +66,11 @@ func (m PowerMessage) InstantaneousPower() (num uint16) {
 // In conditions where packets are lost, average power accurately calculates power over the interval
 // between the received messages.
 func (m PowerMessage) AveragePower(prev PowerMessage) float32 {
-	if prev == nil {
-		return float32(m.InstantaneousPower())
-	}
+	eventCountDiff := m.eventCountDiff(prev)
 
-	if prev.EventCount() == m.EventCount() {
+	if eventCountDiff == 0 {
 		return float32(m.InstantaneousPower())
 	}
 
-	return float32(m.accumulatedPowerDiff(prev)) / float32(m.eventCountDiff(prev))
+	return float32(m.accumulatedPowerDiff(prev)) / float32(eventCountDiff)
 }

ant/speedAndCadenceProfile.go

@@ -36,67 +36,52 @@ func (m SpeedAndCadenceMessage) CumulativeSpeedRevolutionCount() (num uint16) {
 	return
 }
 
-func (m SpeedAndCadenceMessage) SpeedEventTimeDiff(prev SpeedAndCadenceMessage) uint16 {
-	if prev == nil {
-		return 0
-	}
+func (m SpeedAndCadenceMessage) speedEventTimeDiff(prev SpeedAndCadenceMessage) uint16 {
 	return m.SpeedEventTime() - prev.SpeedEventTime()
 }
 
-func (m SpeedAndCadenceMessage) CadenceEventTimeDiff(prev SpeedAndCadenceMessage) uint16 {
-	if prev == nil {
-		return 0
-	}
+func (m SpeedAndCadenceMessage) cadenceEventTimeDiff(prev SpeedAndCadenceMessage) uint16 {
 	return m.CadenceEventTime() - prev.CadenceEventTime()
 }
 
 func (m SpeedAndCadenceMessage) speedRevolutionCountDiff(prev SpeedAndCadenceMessage) uint16 {
 	return m.CumulativeSpeedRevolutionCount() - prev.CumulativeSpeedRevolutionCount()
 }
 
-func (m SpeedAndCadenceMessage) CadenceRevolutionCountDiff(prev SpeedAndCadenceMessage) uint16 {
+func (m SpeedAndCadenceMessage) cadenceRevolutionCountDiff(prev SpeedAndCadenceMessage) uint16 {
 	return m.CumulativeCadenceRevolutionCount() - prev.CumulativeCadenceRevolutionCount()
 }
 
-// Returns the cadence calculated from the previous message (0 if previous message is nil)
-// The second parameter "nochange" indicates that the EventTime counter has not changed since the
-// previous message, which means a complete rotation has not yet occurred. You should use this value
-// to handle cases where the pedal stops: "coasting" (EventTime counter does not change)
+// Cadence Returns the cadence calculated from the previous message
+// If the "ok" parameter is false, this indicates that a complete rotation has not yet occurred.
+// In this case the cadence has not changed, but it is impossible to calculate from these two messages.
+// We can use this to also handle cases where the pedal stops: "coasting" (EventTime counter does not change)
 // Cadence: (RPM)
-func (m SpeedAndCadenceMessage) Cadence(prev SpeedAndCadenceMessage) (cadence float32, nochange bool) {
-	if prev == nil {
+func (m SpeedAndCadenceMessage) Cadence(prev SpeedAndCadenceMessage) (cadence float32, ok bool) {
+	eventCountDiff := m.cadenceEventTimeDiff(prev)
+	if eventCountDiff == 0 {
 		return 0, false
 	}
 
-	if m.CadenceEventTimeDiff(prev) == 0 {
-		return 0, true
-	}
-
-	return float32(m.CadenceRevolutionCountDiff(prev)) * 1024 * 60 / float32(m.CadenceEventTimeDiff(prev)), false
+	return float32(m.cadenceRevolutionCountDiff(prev)) * 1024 * 60 / float32(eventCountDiff), true
 }
 
 // Distance travelled since the last message: (m)
 // circumference: Circumference of the wheel (m)
 func (m SpeedAndCadenceMessage) Distance(prev SpeedAndCadenceMessage, circumference float32) float32 {
-	if prev == nil {
-		return 0
-	}
 	return float32(m.speedRevolutionCountDiff(prev)) * circumference
 }
 
-// Speed: (m/s)
+// Speed in (m/s)
 // circumference: Circumference of the wheel (m)
-// The second parameter "nochange" indicates that the EventTime counter has not changed since the
-// previous message, which means a complete rotation has not yet occurred. You should use this value
-// to handle cases where the pedal stops: "coasting" (EventTime counter does not change)
-func (m SpeedAndCadenceMessage) Speed(prev SpeedAndCadenceMessage, circumference float32) (speed float32, nochange bool) {
-	if prev == nil {
+// If the "ok" parameter is false, this indicates that a complete rotation has not yet occurred.
+// In this case the speed has not changed, but it is impossible to calculate from these two messages.
+// We can use this to also handle cases where the pedal stops: "coasting" (EventTime counter does not change)
+func (m SpeedAndCadenceMessage) Speed(prev SpeedAndCadenceMessage, circumference float32) (speed float32, ok bool) {
+	eventCountDiff := m.speedEventTimeDiff(prev)
+	if eventCountDiff == 0 {
 		return 0, false
 	}
 
-	if m.SpeedEventTimeDiff(prev) == 0 {
-		return 0, true
-	}
-
-	return m.Distance(prev, circumference) * 1024 / float32(m.SpeedEventTimeDiff(prev)), false
+	return m.Distance(prev, circumference) * 1024 / float32(eventCountDiff), true
 }

go.mod

@@ -2,12 +2,4 @@ module github.com/half2me/antgo
 
 go 1.20
 
-require (
-	github.com/google/gousb v1.1.2
-	github.com/redis/go-redis/v9 v9.0.3
-)
-
-require (
-	github.com/cespare/xxhash/v2 v2.2.0 // indirect
-	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
-)
+require github.com/google/gousb v1.1.2

go.sum

@@ -1,10 +1,2 @@
-github.com/bsm/ginkgo/v2 v2.7.0 h1:ItPMPH90RbmZJt5GtkcNvIRuGEdwlBItdNVoyzaNQao=
-github.com/bsm/gomega v1.26.0 h1:LhQm+AFcgV2M0WyKroMASzAzCAJVpAxQXv4SaI9a69Y=
-github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
-github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
 github.com/google/gousb v1.1.2 h1:1BwarNB3inFTFhPgUEfah4hwOPuDz/49I0uX8XNginU=
 github.com/google/gousb v1.1.2/go.mod h1:GGWUkK0gAXDzxhwrzetW592aOmkkqSGcj5KLEgmCVUg=
-github.com/redis/go-redis/v9 v9.0.3 h1:+7mmR26M0IvyLxGZUHxu4GiBkJkVDid0Un+j4ScYu4k=
-github.com/redis/go-redis/v9 v9.0.3/go.mod h1:WqMKv5vnQbRuZstUwxQI195wHy+t4PuXDOjzMvcuQHk=