Parking in a tiny garage is just a pain. I'm always bumping into my garbage cans or whatever boxes I have queued up to be recycled. I have my own visual reference points that I use when parking, but closing one eye and lining up the sunroof on my car with the bracket on the wall gets tiresome.
Inspired by my tiny garage, and jcw from Jeelabs (see: Let's build a GPA) I decided to give it a shot.
1. A light sensor is used to detect when the ultra sonic sensor should start measuring the distance to the car.
2. If there is an invalid distance reading, the red LED will blink once per second.
3. As the car moves towards the target setting (as set by the potentiometer) the green LED begins to blink at a rate of once per 500ms, and as you move closer it blinks faster and faster.
4. Once the car is within a 10 cm window before or after the target, the green and red LEDs light up solid.
5. If you overshoot the target window, the red LED will begin to furiously blink.
Here is my bread board mock up:
I used color coded wires on the perf board so I can see how everything is connected to without thinking too much.
For the final placement, the screen was removed and the unit was placed into a small clear plastic project box. The ultrasonic sensor was mounted to a 2x4 with holes drilled for the transmitters and receivers. Bulk ribbon cable was used to connect the ultrasonic sensor to the main board.
To get the most accurate distance reading, the ultrasonic unit was mounted at my cars bumper height.
NOTE! This is preliminary code that will be further refined, and the VFD display will be eliminated.
| Component | Vendor | Cost |
| SainSmart Arduino Nano | Amazon | $15 |
| SunFouder US-100 Ultrasonic Sensor Module Temperature Compensation | Amazon | $6 |
| Hammond 1591STCL Translucent Polycarbonate Project Box | Amazon | $12 |
| 20pcs Photo Light Sensitive Resistor Photoresistor Optoresistor 5mm GM5539 5539 | Amazon | $6 |
| Jameco Cable Ribbon 40 Conductor Rainbow 28AWG 10 Feet Flat (Only used a small piece) | Amazon | $34 - used ~ $5 worth |
| 10K Breadboard Friendly Trim POT | Adafruit | $2 |
| Total | $46 |
2015-01-25 Teaser Published
2015-03-30 added final placement and costs
2016-08-27 corrected diagram showing red and blue swapped
2016-09-03 new final placement images