feat: Add OCR_MAX_INCR flag

Author: dcelasun

README.md

@@ -135,6 +135,7 @@ All options can be set via CLI flags or environment variables. Flags take preced
 | `--mqtt-device-model` | `MQTT_DEVICE_MODEL` | `Generic` | Model shown in Home Assistant |
 | `--meter-divisor` | `METER_DIVISOR` | `1000` | Divisor to convert raw reading to m³ (e.g. `000354225` / `1000` = `354.225`) |
 | `--ocr-incr-only` | `OCR_INCR_ONLY` | `false` | Only publish readings that are ≥ the previous value (after dividing by `meter-divisor`), discarding likely OCR errors |
+| `--ocr-max-incr` | `OCR_MAX_INCR` | `0` | Maximum allowed increase between consecutive readings (after `meter-divisor`); larger jumps are discarded as OCR errors (`0` = disabled) |
 
 ### MQTT / Home Assistant
 

http.go

@@ -129,13 +129,20 @@ func processOCR(imageData []byte, batLevel, batVoltage int) {
 
 	divided := val / meterDivisor
 
-	if ocrIncrOnly {
+	if ocrIncrOnly || ocrMaxIncr > 0 {
 		lastReadingMu.Lock()
 		prev := lastReading
-		if !math.IsNaN(prev) && divided < prev {
-			lastReadingMu.Unlock()
-			log.Printf("OCR incr-only: discarding reading %.3f < previous %.3f", divided, prev)
-			return
+		if !math.IsNaN(prev) {
+			if ocrIncrOnly && divided < prev {
+				lastReadingMu.Unlock()
+				log.Printf("OCR incr-only: discarding reading %.3f < previous %.3f", divided, prev)
+				return
+			}
+			if ocrMaxIncr > 0 && divided-prev > ocrMaxIncr {
+				lastReadingMu.Unlock()
+				log.Printf("OCR max-incr: discarding reading %.3f, increase %.3f > max %.3f (previous %.3f)", divided, divided-prev, ocrMaxIncr, prev)
+				return
+			}
 		}
 		lastReading = divided
 		lastReadingMu.Unlock()

main.go

@@ -31,6 +31,7 @@ var (
 	mqttDeviceModel        string
 	meterDivisor           float64
 	ocrIncrOnly            bool
+	ocrMaxIncr             float64
 	ocrMergeTexts          bool
 )
 
@@ -143,6 +144,11 @@ func main() {
 				Usage:   "Only publish readings that are >= the previous reading (after dividing by meter-divisor), discarding likely OCR errors",
 				Sources: cli.EnvVars("OCR_INCR_ONLY"),
 			},
+			&cli.FloatFlag{
+				Name:    "ocr-max-incr",
+				Usage:   "Maximum allowed increase between consecutive readings (after dividing by meter-divisor); larger jumps are discarded as OCR errors (0 = disabled)",
+				Sources: cli.EnvVars("OCR_MAX_INCR"),
+			},
 		},
 		Action: run,
 	}
@@ -171,6 +177,7 @@ func run(_ context.Context, cmd *cli.Command) error {
 	mqttDeviceModel = cmd.String("mqtt-device-model")
 	meterDivisor = cmd.Float("meter-divisor")
 	ocrIncrOnly = cmd.Bool("ocr-incr-only")
+	ocrMaxIncr = cmd.Float("ocr-max-incr")
 	ocrMergeTexts = cmd.Bool("ocr-merge-texts")
 
 	if mqttBroker != "" {