计算传感器的不确定长度的移动平均值

Question

我试图计算传感器返回的值的运行平均值，并在平均值满足两个条件（array.length == x && avg

let arr = []
let avg = 0
let sum = 0

sensor.calibrate(() => {
  sensor.getMeasurement((volts) => {
    console.log(volts) // typical values are ~0.9 V
    runningAvg(volts, 0.85, 10)
  })
})

function runningAvg(item, threshold, length) {
  if (array.length < length) {
    array.push(item)
  } else {
    array.shift().push(item)
    for(let i=0; i < array.length; i++) {
      sum += array[i]
    }
    avg = sum / length
  }
  if(avg < threshold && array.length == length) console.log(avg)
}

此代码返回0。

当平均值为<阈值和array.length == length时，如何计算运行平均值并运行一些代码？