feat: publish pwm feedback

pkg/tools/thresholdconfig.go

@@ -0,0 +1,65 @@
+package tools
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+var (
+	defaultThresholdConfig = ThresholdConfig{
+		ThresholdSteps: []float64{0.07, 0.08, 0.09, 0.1, 0.125, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0},
+		MinValid:       500,
+		Data:           []int{8700, 4800, 3500, 2550, 1850, 1387, 992, 840, 750, 700, 655, 620, 590, 570, 553, 549, 548},
+	}
+)
+
+func NewThresholdConfig() *ThresholdConfig {
+	return &defaultThresholdConfig
+}
+
+func NewThresholdConfigFromJson(fileName string) (*ThresholdConfig, error) {
+	content, err := os.ReadFile(fileName)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read content from %s file: %w", fileName, err)
+	}
+	var ft ThresholdConfig
+	err = json.Unmarshal(content, &ft)
+	if err != nil {
+		return nil, fmt.Errorf("unable to unmarshal json content from %s file: %w", fileName, err)
+	}
+	return &ft, nil
+}
+
+type ThresholdConfig struct {
+	ThresholdSteps []float64 `json:"threshold_steps"`
+	MinValid       int       `json:"min_valid"`
+	Data           []int     `json:"data"`
+}
+
+func (tc *ThresholdConfig) ValueOf(pwm int) float64 {
+	if pwm < tc.MinValid || pwm > tc.Data[0] {
+		return 0.
+	}
+	if pwm == tc.Data[0] {
+		return tc.ThresholdSteps[0]
+	}
+
+	if pwm < tc.Data[len(tc.Data)-1] && pwm >= tc.MinValid {
+		return 1.
+	}
+	// search column index
+	var idx int
+	// Start loop at 1 because first column should be skipped
+	for i := 1; i < len(tc.ThresholdSteps); i++ {
+		if pwm == tc.Data[i] {
+			return tc.ThresholdSteps[i]
+		}
+		if pwm > tc.Data[i] {
+			idx = i - 1
+			break
+		}
+	}
+
+	return tc.ThresholdSteps[idx] - (tc.ThresholdSteps[idx]-tc.ThresholdSteps[idx+1])/2.
+}