Computer Control: Flowol

1. Introduction

Flowol is a program for controlling objects, either on screen in simulation mode or, through an interface, real-world items such as lights, buzzers and sensors. Objects are controlled by creating flow charts that turn them on and off or read their values from sensors. Flowcharts are, effectively, computer programs. It should be easier to write computer programs with a visual flowchart language than in code.

2. The Toolbar and Symbols

The main symbols in a flowchart are as follows:

• Rounded rectangle - Start or Stop
• Parallelogram - output - turn something on or off such as a motor
• Rectangle - process such as waiting for a few seconds
• Diamond - decision, based on an input such as 'is it dark?' or 'is the button pressed?'

These can be seen in the Flowol toolbar.

Other symbols in the toolbar include:

• Cross - delete
• T - text label
• Hand - edit
• Line - add line
• Red triangle - run flowchart

To build a flowchart click on the symbol required and then click on the main canvas.

When a shape is placed on the canvas you can set up processes. Processes include reading inputs, turning outputs on and off and setting delays.

You can test what the inputs and outputs are connected to by clicking on the numbers in the toolbar at the bottom of the screen:

With the Bridge Light mimic loaded clicking on the Outputs will show you which outputs are connected to which lights. You can also click on the lights themselves to turn them on and off.

3. Placing Flowchart Symbols

When flowchart symbols are placed on the canvas a dialogue box opens at the bottom of the screen. The contents of the dialogue box depend on which shape was dropped onto the canvas. Choose the option from the dialogue box that suits what you want to do.