Intro: Reverse Engineering & Upgrading Car Parking Sensors
This instructable shows you to understand reverse engineering, analysing data and developing new product with these information.
Step 1: Finding Out Pinouts
In order to understand working principle of parking sensor, I needed to specify correct data pin. Then I measured voltage levels with multimeter and saw that there is 3-pin connection between Display unit and main unit, 4th cable is not working which are:
- GND - BLACK
- VCC - RED
- DATA - WHITE
I connected black one with ground and white one to Channel 1 of logic analyser.
Step 2: Connecting Logic Analyzer & Exploring Working Principle
After working for a week on understanding the meaning of bits, I found out that the first byte represents distance in a form of inverse of each bit, following 4 bits are sensor id and last 4 bits are stop bits.
Step 3: Adding a New "Speech" Future With Using Arduino & Serial Mp3 Player Module
I measured the durations of Start Signal, logical 1 and logical 0 in micro seconds. It helped me to split them into these three forms. Also I connected the data bus to arduino nano interrupt pin (D2).
After I extracted the data, I wrote a program that can sends command to serial mp3 player via uart. I used softwareserial D8 D9 on arduino.
Arduino Nano link is here
Mp3 module link is here
Arduino Nano Code is in the attachment
Step 4: File Paths in Microsd Card (Mp3 Player)
- 01\001.mp3 --> its welcome message
when you switch your car into reverse gear, you will meet with this.
the other files are like :
- 01\002.mp3 --> 10-20 cm.
- 01\003.mp3 --> 20-30 cm.
- 01\004.mp3 --> 30-40 cm.
- 01\005.mp3 --> 40-50 cm.
- 01\006.mp3 --> 50-60 cm.
Step 5: Designing the Circuit and PCB
Step 6: Ordering the JST XH Connectors and Speaker
Step 7: Final Part : Soldering PCB
It works perfectly! :)