Arduino Parking Sensor

For this project, I made a parking sensor. In my parking lot, I keep hitting my bumper on the stairs at the end of my parking spot, and I wanted something to help me know how far to pull in. So I made this parking sensor to tell me when to stop.

I used this instructable for help with my code and wires :)

https://www.instructables.com/Circuit-Playground-Express-and-Ultrasonic-Distance/

For this project, you'll need

• arduino circuit playground express
• battery pack (I used one with three AAA batteries)
• HC-SR04 ultrasonic sensor
• piezo buzzer
• wire (any size will do)
• two 2.2 kohm resistors
• a box (I spray pained mine silver)
• hot glue
• soldering iron

First thing I did was to code my arduino. I used makecode adafruit circuit playground express (makecode.adafruit.com). I made this so that the lights will always be green. Once the car is within 31cm (approximately 1ft), the light will change to be red and will send out a beeping sound.

First thing that I did was solder the wires to the Vcc, Trig, and Gnd, parts of the ultrasonic sensor. I also soldered wires to both of the metal parts of the piezo buzzer. This way I could connect them to the arduino a little easier.

Any wires will work, but I found that the thinner wires were a little easier to connect with the solder.

Next, I soldered one of the resistors to a wire and then I soldered the wire to the echo connection.

I wanted all the wires to be inside the box so that you wouldn't see them. So I measured out where the sensors were going to be and where I would need to cut so that you could connect the wires underneith.

On the top, I put the ultrasonic sensor. I traced it with a pencil and then traced a square of where I would need to cut so that the wire connections would be inside the box.

I traced the arduino and then traced where the holes are on the side and then where the battery connection would be on the bottom.

I then traced a hole for the piezo buzzer so that it could slide in there.

I then cut the holes out but also left room where the ultrasonic sensor and arduino could be glued and connected to the box.

Next, I hot glued the ardino to the box. I stuck the wires in from the ultrasonic sensor and the piezo buzzer and then glued those on to the box. All of the wires are inside of the box

Note : I had my resistors hooked up wrong at first. They should not be connected, but one should be hooked up to the wire and the other will be on its own.

I attached all of the wires to the arduino

ULTRA SONIC SENSOR :

Vcc --> Vout

Echo --> (first) resistor --> A1

A1 --> (second) resistor --> ground

Trig --> A2

Gnd --> ground

PIEZO BUZZER :

one wire to A0

one wire to ground

after I put the wires where they need to go, I soldered them down to the arduino

** you could put the wires on the outside of the box, I just didn't want to see them

Next, I hot glued the battery pack into the box. For this, I put hot glue around the sides and made sure that the on / off switch was outside for easy access to turn it on and off. I also made sure that I wasn't gluing the top on so that I could take off the top to change out the batteries when needed.

Then, I plugged in the battery pack to the arduino

Test out your parking sensor and enjoy!