11

Way Home Meter

TUTORIAL

Place your protractor on the centre point and mark

every 18 degrees. Then, using a ruler, line up the

centre point and these new marks; where this line

intersects with the semicircle is where each LED

should be placed. Starting on the side that you want

to be the front, use the 4 mm drill bit by hand (no

power drill needed) to create a hole for each of the

LEDs where you have marked.

Measure the dimensions of your servo and mark

it on around the centre point. Remember that the part

of the servo that rotates should be the centre point,

so offset the servo shape to suit. Cut the shape out

of the foam board and place the servo through from

the front.

Finally, you will need to place the buzzer module.

You can simply place the pins of the module into the

foam to mark where the holes should be and, using a

piece of wire, pierce the two holes so they go through

the foam board.

ON THE FINAL STRETCH

Place all the LEDs into the foam board from the

back. Bend the input pin of each LED back towards

the previous LED, and bend the output pin of each

towards the input pin of the next LED, and solder

them together. Slightly bend all the Ground pins

of the LEDs towards the centre of the circle and

all VCC pins away from the centre of the circle. Solder

wire between all the Ground and VCC pins.

Place the dot matrix PCB in the cut-out, and put

all the panels back in place. Pay careful attention

Right

Foam board all cut

and LEDs placed.

The foam board will

be clamped between

the display module

and the PCB

It’s a good idea to

practise cutting

out the shapes

and making the

LED holes using

scrap pieces of the

foam board!

QUICK TIP

You can take this project and make it differently,

depending on your requirements. Here are a

few suggestions:

-^ Add the ability to send the device a location and
time, and have it calculate when you need to leave
your home to make it on time.

• Add support for multiple people. Currently the
  device will request the travel time for the person
  who last sent a coordinate and display the correct
  name and information for them, but this could be
  improved to handle multiple people.


• Configurable alarms. Get notified when a
  person is X number of minutes away. Useful for
  starting dinner!

GOING FURTHER