pixl.js with analog moister sensor

I came up with this

var high = 0.55;
var low = 0.0017;

function map_value(val, in_min, in_max, out_min, out_max){
  var result = (val - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
  
  if(result < out_min) {
    return out_min;  
  } 
  else if(result > out_max) {
    return out_max;
  }
  
  return result;
}

function onTimer() {
  var h = analogRead(A0);
  var hp = map_value(h, low, high, 0, 100);
  var percentage = hp.toFixed(0)+"%";
  
  // Clear display
  g.clear();
  // Use the small font for a title
  g.setFontBitmap();
  g.drawString("Soil moister:");
  // Use a large font for the value itself
  g.setFontVector(10);
  g.drawString(percentage, 5,10);
  // Update the screen
  g.flip();
}

// Update soil moister every 2 seconds
setInterval(onTimer, 2000);
// Update soil moister immediately
onTimer();

Feedback on the code is welcome

I have 3 pucks im gooing to try next :) Im gooing to send via bluetooth to my pixl.js

edit:
Strange the high and low changes with battery vs plug