don't filter or throttle serial, let the user deal with it.

libs/microbit/led.ts

@@ -8,10 +8,6 @@ namespace led {
     let barGraphHigh = 0;
     // when was the current high value recorded
     let barGraphHighLast = 0;
-    // last time serial was written
-    let barGraphLastSerialMessage = 0;
-    // last filtered value
-    let barGraphFilteredValue = 0;
         
     /**
      * Displays a vertical bar graph based on the `value` and `high` value.
@@ -22,13 +18,9 @@ namespace led {
     //% help=/led/plot-bar-graph weight=20
     //% blockId=device_plot_bar_graph block="plot bar graph of %value |up to %high" icon="\uf080" blockExternalInputs=true
     export function plotBarGraph(value: number, high: number): void {        
-        value = Math.abs(value);
-        barGraphFilteredValue = (barGraphFilteredValue * 3 + value * 7) / 10;
         let now = input.runningTime();
-        if (now - barGraphLastSerialMessage > 100) {
-            serial.writeString(barGraphFilteredValue.toString() + "\r\n");
-            barGraphLastSerialMessage = now;
-        }
+        serial.writeString(value.toString() + "\r\n");
+        value = Math.abs(value);
         
         if (high != 0) barGraphHigh = high;
         else if (value > barGraphHigh || now - barGraphHighLast > 5000) {