Watch Your Kid Using Radio of Micro:bit

by madmakerclub

14800

Intro: Watch Your Kid Using Radio of Micro:bit

We sometimes hear of the accidents involving kids, causing injury and deaths. These are some possible reasons I can think of:

  1. the parents have other things to attend to and cannot keep an eye on the kids;
  2. the parents are thinking about other things and have forgotten about the kids;
  3. the parents are careless.

If there is something to remind the parents to watch over their kids, these accidents might could be avoided.

Watch Your Kid consists of 2 sets of wearable worn by the kid and the parent respectively

The Micro:bits are coded so that it can function as alarm when the kid is too far from the parent.

The radio of Micro:bit allows wireless communication between the two wearables.

Note: It works most of the time but may still fail too due to certain conditions. So, it is strongly advisable to be used for learning and entertainment purpose only.

STEP 1: Make Kid's Wearable (pouch) - Cut the Cloth

Make a pouch as the wearable for the kid. Cut out a cloth of 17cm x 14 cm.

STEP 2: Fold the Cloth

Fold the cloth upward to the size of 17 cm x 9 cm.

STEP 3: Fold the Cloth

Fold the both right and left sides of the cloth inward to the size of 10 cm x 9 cm (to keep the battery holder with wires).

STEP 4: Sew the Cloth

Sew both the right and left sides of the cloth into a pouch. The pouch is done.

STEP 5: Complete the Circuit

Complete the circuit. Make 2 sets of it.

STEP 6: Prepare Circuit to Be Put in Pouch

Put the battery holder below Micro:bit. Arrange wires and put them below battery holder.

STEP 7: Kid's Wearable Done

Put the circuit into the pouch. Pinned it at both sides on the kid's clothes. Arrange the buzzer so that it faces outward. The wearable for the kid is done.

STEP 8: Make Parent's Wearable (Velcro Strap)

Cut out 5 cm x 22 cm of double-sided tape. Cut out some cloth to be pasted at the front and the back of it. Cut a set of Velcro (5 cm x 5cm). Paste them at the ends of the front and the back of the cloth.

STEP 9: Parent's Wearable Done

Fix the circuit on the strap.

STEP 10: The Code

Code in Makecode Editor.

  • It shows the icon of a baby trolley on start so that the user knows it is working.
  • Set radio group to 1 so that both micro:bits are connected to the same channel.
  • Radio send number 0 to transfer data consistently(forever).
  • Signal strength: the value ranges from -128 to -42 (-128 means a weak signal and -42 means a strong one.)
  • When the kid is next to the parent, it shows the icon "✔".
  • When the kid starts to walk away from the parent, the signal of -42 will drop. When the distance is about 1 meter, the signal would fall below -65. This will trigger the buzzer and show the icon of "X".
  • Download the code to both the Micro:bits.

Click here for the sample code.

STEP 11: Demo

In the video, the rabbit acts as the kid, whereas the frog acts as the parent.