Introduce generic filters concept, add high-pass filter

README.md

@@ -40,6 +40,7 @@ to any number of different targets, such as databases or MQTT.
 * Supports arbitrary _**grouping of devices**_
   * A group can be for example "Heating" or "Lights". This allows users to get a better overview of their energy 
     consumption when many circuits and devices are involved.
+* Can apply various _**filters**_ to the power sensor data (clamping, high-pass etc.)
 * Can _**measure unmetered power**_ too
   * You can have a current-transformer type sensor measuring a circuit, then a smart plug measuring some specific 
     device on that circuit, then an unmetered type sensor which calculates the difference between the two, yielding the 

examples/config.sample.full.yml

@@ -31,7 +31,8 @@ circuits:
           - Vägg vardagsrum
           - Vägg kök
           - Vägg arbetsrum
-      clamp: positive # Don't allow negative values
+      filters:
+        clamp: positive # Don't allow negative values
   # A IotaWatt main circuit, phase A/L1
   - name: Main L1
     type: main
@@ -78,6 +79,8 @@ circuits:
       iotawatt:
         address: 10.112.4.4
         name: Vagg_Kok
+      filters:
+        highPass: 2 # Ignore loads less than 2 watts (show as 0)
     group: Matlagning
   # Yet another IotaWatt circuit. This one has a different "parent" than the others.
   - name: Vägg arbetsrum
@@ -145,7 +148,8 @@ circuits:
         unit: 100
         register: 866
         type: int16
-      clamp: positive
+      filters:
+        clamp: positive
 
 #
 # Characteristics. Characteristics mean voltage and frequency, and potentially other non-power related readings.

src/eachwatt.ts

@@ -11,6 +11,7 @@ import { pollCharacteristicsSensors } from './characteristics'
 import { createLogger } from './logger'
 import { setRequestTimeout as setHttpRequestTimeout } from './http/client'
 import { setRequestTimeout as setModbusRequestTimeout } from './modbus/client'
+import { applyFilters } from './filter/filter'
 
 // Set up a signal handler, so we can exit on Ctrl + C when run from Docker
 process.on('SIGINT', () => {
@@ -54,14 +55,14 @@ const mainPollerFunc = async (config: Config) => {
   const characteristicsSensorData = await pollCharacteristicsSensors(now, config.characteristics)
 
   // Post-process power sensor data
-  for (const data of powerSensorData) {
+  for (let data of powerSensorData) {
     if (data.power !== undefined) {
       // Round all numbers to one decimal point
       data.power = Number(data.power.toFixed(1))
 
-      // Optionally clamp values
-      if (data.circuit.sensor.clamp === 'positive') {
-        data.power = Math.max(0, data.power)
+      // Apply optional data filters
+      if (data.circuit.sensor.filters) {
+        data = applyFilters(data.circuit.sensor.filters, data)
       }
     }
   }

src/filter/filter.ts

@@ -0,0 +1,25 @@
+import { PowerSensorData } from '../sensor'
+
+export type PowerSensorFilters = {
+  clamp?: 'positive'
+  highPass?: number
+}
+
+export const applyFilters = (filters: PowerSensorFilters, data: PowerSensorData): PowerSensorData => {
+  if (data.power === undefined) {
+    return data
+  }
+
+  // Clamp
+  if (filters?.clamp === 'positive') {
+    data.power = Math.max(0, data.power)
+  }
+
+  // High-pass
+  const highPass = filters?.highPass
+  if (highPass !== undefined && data.power < highPass) {
+    data.power = 0
+  }
+
+  return data
+}

src/sensor.ts

@@ -1,5 +1,6 @@
 import { Circuit } from './circuit'
 import { Characteristics } from './characteristics'
+import { PowerSensorFilters } from './filter/filter'
 
 export enum SensorType {
   Iotawatt = 'iotawatt',
@@ -36,7 +37,7 @@ export type CharacteristicsSensorPollFunction = (
 export interface PowerSensor {
   type: SensorType
   pollFunc: PowerSensorPollFunction
-  clamp?: 'positive'
+  filters?: PowerSensorFilters
 }
 
 export interface CharacteristicsSensor {

src/sensor/dummy.ts

@@ -12,8 +12,6 @@ import { Characteristics } from '../characteristics'
 export const getSensorData: PowerSensorPollFunction = async (
   timestamp: number,
   circuit: Circuit,
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  existingSensorData?: PowerSensorData[],
 ): Promise<PowerSensorData> => {
   return emptySensorData(timestamp, circuit)
 }

tests/filter/filter.test.ts

@@ -0,0 +1,52 @@
+import { emptySensorData, PowerSensorData, SensorType } from '../../src/sensor'
+import { applyFilters, PowerSensorFilters } from '../../src/filter/filter'
+import { Circuit } from '../../src/circuit'
+import { getSensorData as getDummySensorData } from '../../src/sensor/dummy'
+import exp = require('node:constants')
+
+test('clamping works', () => {
+  const filters: PowerSensorFilters = {}
+  let data: PowerSensorData = dummySensorData()
+
+  data.power = 10
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(10)
+
+  data.power = -10
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(-10)
+
+  filters.clamp = 'positive'
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(0)
+})
+
+test('high-pas works', () => {
+  const filters: PowerSensorFilters = {}
+  let data: PowerSensorData = dummySensorData()
+
+  data.power = 100
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(100)
+
+  data.power = 1.5
+  filters.highPass = 2
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(0)
+  data.power = 3
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(3)
+})
+
+const dummySensorData = (): PowerSensorData => {
+  const circuit: Circuit = {
+    name: 'dummy',
+    children: [],
+    sensor: {
+      type: SensorType.Dummy,
+      pollFunc: getDummySensorData,
+    },
+  }
+
+  return emptySensorData(0, circuit)
+}