The circuit below is the same as the first PICAXE-08 circuit with the exception that a dark sensor circuit replaces the ordinary switch. Crocodile Technology software can be used to test the circuit before it is made with real components. The LEDs are outputs. Almost all circuits can be divided into INPUT, PROCESS and OUTPUT. These are clearly identified below.

The circuit above has a simple light sensor in the place of a push switch or pressure pad. When the light level rises, the resistance in the LDR falls and this eventually allows current to flow into the base of the transistor, energising the relay.
The relay is connected to Input 1 of the PICAXE-08. The sequence of LEDs turning on and off is determined by the flowchart below. Both the circuit and the flowchart have been created using Crocodile Technology® software. The flowchart is linked to the circuit and consequently it controls its actions;

1. A START box is selected from the menu and placed in the working area.

2. A decision box, called a ‘Test Input’ is connected to the start box. The text in the centre of the box is changed so that Input 1 is continually tested for activation. If input 1 is activated the programme moves down to the next line of the programme (the next process box). If Input 1 is not activated, the decision box continues to check for any change.

3. This process box (called Set Output) switches on Output 4, which in the case of the circuit above turns on an LED.

4. The Delay Box is set to 5 seconds and causes the programme to stay at this point for that time.

5. Output 4 is then switched off. This has the effect of turning off the LED.

6. Output 0 is then switched on, turning on the LED controlled by it.

7. Output 0 is kept on for 5 seconds and consequently the LED stays on.

8. Output 0 is turned off and, as a result, the LED.

9. A Stop box is always placed at the end of a flowchart. The programme comes to an end.

Crocodile Technology Software allows the translation of the flowchart into BASIC programming language. This is extremely useful if the programmer / circuit designer normally uses BASIC to programme the PICAXE-08 and other PICAXE ICs.
When the circuit has actually been made, the programme can be exported to it through the export command. The flow chart system simplifies programming.

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