plot Bar Graph

Display a bar graph for a number value.

led.plotBarGraph(2, 20);

A bar graph is a kind of chart that shows numbers as lines with different lengths. The value is plotted in LEDs as a ratio of a value to the high value you set as a maximum range. So, if there are 25 LEDs on the screen, then plotting 9 for the high value of 50 would display about 5 LEDs on the screen.

Parameters

  • value: a number that is the value of what you are measuring or trying to show. For example, if you are measuring the temperature of ice with the micro:bit, value might be 0 if the temperature is 0 degrees Celsius.
  • high: a number that is the highest possible number (maximum) that the value parameter can be. The lines in the bar graph will reach their highest point when value reaches this number. If high is 0, then the largest value recently plotted is used as the maximum.
  • valueToConsole: a boolean value that when true will also send the value to the serial port. A value of false will prevent the number in value from going to the serial output.

Serial Output

The ||led:plot bar graph|| block will also write the number from value to the serial port if you set the valueToConsole parameter to true. This is a way to help you record the values you’ve plotted.

Example: chart acceleration

Show a bar graph of the acceleration in the x direction of the micro:bit. The micro:bit’s x direction is from left to right (or right to left). The faster you move the micro:bit in this direction, the taller the lines in the bar graph will be. The high paramter is 1023 which sets the highest possible value of acceleration to show. Also, record the acceleration value by sending it to the serial port.

basic.forever(() => {
    let a = input.acceleration(Dimension.X);
    led.plotBarGraph(a, 1023, true)
})

See also

brightness, fade in, fade out, LED screen, stop animation