select filter in config file

config.toml

@@ -3,11 +3,17 @@
 port = 9090                     # web port
 debug = true                    # enable to use simulated PCB for development
 
+# all DB settings are individual to each DB
 [DB]
 type = "sqlite3"
 path = "test.db"
 freq = 60
 
+# Configure channel 1
+# type = 'U' => UV, else use other letters for resp type
+# filter.samples => sample buffer size
+# filter.type    => filtering function to use [0-3; 0 default]
+
 [Channel_1]
 type = 'U'               
 filter.samples = 100

config/config.go

@@ -76,6 +76,7 @@ func Load() (config.Config, error) {
 		v.SetDefault(head+".unit", "UV")
 		// filter settings
 		v.SetDefault(head+".filter.samples", 50)
+		v.SetDefault(head+".filter.type", 0)
 	}
 
 	for i := 1; i < 8; i++ {

core/th7/service.go

@@ -50,11 +50,9 @@ func startCacheService(t *TH7Adapter) {
 			time.Sleep(DurWaitBetweenChannel)
 		}
 
-		// do alpha~beta on each channel,
-		// putting the value in
-		// TODO: in config have different types.
+		// apply filter to each set of samples. First run will be noisy.
 		for i := range samples {
-			data[i].Value = filter.AlphaBetaFilter(samples[i], data[i].Value)
+			data[i].Value = filter.FilterByType(t.cfg.Channels[i].Filter.Type, samples[i], data[i].Value)
 		}
 
 		// read pcb temp and apply CJC

filter/filter.go

@@ -1,6 +1,21 @@
 package filter
 
-func AlphaBetaFilter(arr []float64, init float64) float64 {
+func FilterByType(t int, arr []float64, init float64) float64 {
+	switch t {
+	case 0:
+		return AlphaBeta(arr, init)
+	case 1:
+		return Lag_1(arr, init)
+	case 2:
+		return Lag_2(arr, init)
+	case 3:
+		return Lag_3(arr, init)
+	}
+
+	return AlphaBeta(arr, init)
+}
+
+func AlphaBeta(arr []float64, init float64) float64 {
 
 	value := init
 	for i := range arr {