Add scale filter, useful for Modbus sensors

src/filter/filter.ts

@@ -3,6 +3,7 @@ import { PowerSensorData } from '../sensor'
 export type PowerSensorFilters = {
   clamp?: 'positive'
   highPass?: number
+  scale?: number
 }
 
 export const applyFilters = (filters: PowerSensorFilters, data: PowerSensorData): PowerSensorData => {
@@ -21,5 +22,11 @@ export const applyFilters = (filters: PowerSensorFilters, data: PowerSensorData)
     data.power = 0
   }
 
+  // Scale
+  const scale = filters?.scale
+  if (scale !== undefined) {
+    data.power = data.power / scale
+  }
+
   return data
 }

tests/filter/filter.test.ts

@@ -2,7 +2,6 @@ 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 = {}
@@ -21,7 +20,7 @@ test('clamping works', () => {
   expect(data.power).toEqual(0)
 })
 
-test('high-pas works', () => {
+test('high-pass works', () => {
   const filters: PowerSensorFilters = {}
   let data: PowerSensorData = dummySensorData()
 
@@ -38,6 +37,20 @@ test('high-pas works', () => {
   expect(data.power).toEqual(3)
 })
 
+test('scale works', () => {
+  const filters: PowerSensorFilters = {}
+  let data: PowerSensorData = dummySensorData()
+
+  data.power = 155
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(155)
+
+  data.power = 155
+  filters.scale = 0.1
+  data = applyFilters(filters, data)
+  expect(data.power).toEqual(1550)
+})
+
 const dummySensorData = (): PowerSensorData => {
   const circuit: Circuit = {
     name: 'dummy',