Micro Switch

The Micro Switch (SPDT) is very similar to other switches but it has one main difference – It can be used in a few different ways. A Micro Switch works in such a way that rather than stopping the flow of electricity, it directs it one of two ways. Imagine a T-junction on a road, with a policeman stood in the middle. As you drive up to the junction, the policeman can direct you one of two ways, left or right. If you want, you can use this switch in three different ways: push-to-make, push-to-break or as a single-pole, double-throw (SPDT) switch.

There are a few ways to connect a toggle switch to the Crumble. First of all, you need to connect the common (com) pad on the switch to a + output, either from the battery pack or the Crumble. Then you can connect one of the other two pads (normally open or normally closed) to an input (A, B, C or D). Which one you choose will have the opposite effect. 

To make a push-to-make switch, you need to connect the ‘normally open’ pad to an input (A ,B, C or D). When the switch is pushed down, the electricity will flow through your circuit and make the input HI. When released, the chosen input will become LO again. To make a push-to-break switch, you need to do the opposite of what we did previously. You must connect the ‘normally closed’ pad to an input (A, B, C or D) instead. This time, the current will always flow through to your input, making it HI, but when you press the switch down, the circuit is broken and the input will become LO.

Note: Don’t forget you will need to add batteries.

Screeny Shot 9 Nov 2017, 12.17.25

We use this block to monitor our chosen input. Whenever the button is pressed, current will be going through your chosen input e.g. A. You can change the options by clicking the letter or HI.

Screeny Shot 9 Nov 2017, 12.40.07

Push-to-make switch (left) – Whilst the switch is pressed down, all of the sparkles will turn purple. Push-to-break switch (right) – The Sparkles are set to shine purple unless the switch is pressed, then they will turn off..

Here is the Crumble running the first block of code.

Where next?

The micro switch has a surprising number of uses. It can be used to provide multiple inputs to the Crumble, be used to control lights, motors, servos or even, be used as an obstacle detector!