[chiro3110]

So, with still a few days to let go of the lockdown, boredom had got the better part of me. Tried my hand at almost anything which I could think of including cooking some weird dishes (some were good, some were not!), trying a bit of wood work, exercising and definitely binge watching several stuff on OTT platforms. However, my love for making small DIY projects was going unfulfilled mostly due to the closure of online shopping and restricted finances as I'm unable to go back to work for the time being. I started looking at all the stuff I had at home and think of some project. What did I find there?

1. An Arduino Uno
2. An Ultrasonic distance measurement sensor

So kept thinking what do do with them when finally I had the idea to assemble a makeshift radar system for my garage. This would help in placing the car at the correct position: not too close to the walking path (to access pump and water reservoir) and not too far to have issues closing and locking the garage door. For this I would atleast need a power adapter (to power up the Arduino and sensor) and some LEDs. I soon found a spare torch with some LED strips in it. Out comes the destroyer in me to rip apart the case and salvage the LEDs! (not to mention the torch getting unusable henceforth)



After getting the parts ready, connected them up for a prototype circuit to check the the proof of concept and get the Arduino code ready as well. Once satisfied with the code, uploaded it and tested for the proper working of the circuit. I measured manually the proper distance where the green/red LEDs should fire up, added some tolerance and it was good to go. Here was a little bit of a technical hurdle. LEDs work at 3.5-4 V, where as Arduino works and supplies 5V over the digital pins. Normally one would add resistors to the LED to make it work but since there was no store or online ordering available something else was to be done. I used PWM (Pulse Width Modulation) to power the LEDs instead. The PWM pin was powered at around 30% (80 out of 255 steps), this would translate to the digital pin only having 5V on it for 30% of the time. This would effectively reduce the exposure and hence prevent the burn down of the LEDs. It seemed to be working fine. (so far!)




Next, it was time to set the project in an enclosure and finalize the wires and power lines. Thanks to my tools: Drill machine and Dremel Rotary the assembly task was fairly simple and done in a a couple of hours. Another dry test was done to check if all connections were proper. The assembly was completed and so far I was happy with with I had. It did not look professional but still it was suppose to be a DIY and it worked fine.




Last step before testing, to actually install in the garage. The sensor was aligned to the tentative car's number plate position (since it is the only flat surface to maximize the efficiency of the ultrasonic sensor, rough surface might bring attenuation). The LED strips (now covered with red and green paper) was attached with twist tie to the stair's handrail somewhere in line with the driver's range of vision. The wires did look a bit untidy, but was fine. It wasn't going to be a fully permanent installation but just a hobby lockdown project. Proabably with the proper parts a final always on version can be done. The power cable is actually attached to a smart switch which can powered on demand thru smartphone so normally it was off.





Now finally to testing hour. It's better with a video. P.S. It wasn't shot on a dashcam (still researching it on Team-BHP to narrow down) but with the mobile mounted on the windshield.

(Please seek to 9:20 for the final approach)

https://www.youtube.com/watch?v=KcYRmmnmaos

[Aditya]

Thread moved out from the Assembly Line. Thanks for sharing!

[mayankk]

How close were you before the lights turned red? It's pretty nifty, you ought to do a trial production of 6-7 units and sell it in the classifieds.

[chiro3110]

Originally Posted by mayankk

How close were you before the lights turned red? It's pretty nifty, you ought to do a trial production of 6-7 units and sell it in the classifieds.

I manually measured the correct parking spot's distance from the sensor installation area which came around 155 cm. To that added a small tolerance of 3 cm. Then this value was coded to the Arduino.

Thank you very much for the idea. Honestly, I never thought from a commercial standpoint. Probably a similar offering can be made in around 5000 INR. Though I can see the downers, firstly the distance of transition green-red is hard-coded to the Arduino which would be a variable for most. Secondly, some sort of reverse engineered car park sensor might also do the trick which probably sells for a lot less. But, thank you very much the proposition was very welcoming; might think about this if any workable solution comes to my mind for the above two issues.

[haisaikat]

Congratulations, well done indeed.

Until you are production ready, I believe a few convex mirrors placed around can also help in the meantime for those who are looking for a stop gap.

[jothishX]

Nice project. I would suggest (once the lockdown ends) to get the cheaper JSN-SR04T sensor (about Rs. 500) instead of the Maxbotix sensor (about 8k). The sensor is the same that is used in cars and is also waterproof. I've been using one for measuring the water level in my overhead tank and has been running for two years after being in the sun and rain.

[blackwasp]

Originally Posted by chiro3110

So kept thinking what do do with them when finally I had the idea to assemble a makeshift radar system for my garage. This would help in placing the car at the correct position: not too close to the walking path (to access pump and water reservoir) and not too far to have issues closing and locking the garage door.

Wow, this is very neat and quite handy I must say. You could even retrofit a similar one on the car bumpers itself giving you a front and year parking sensors with realtime range display (you might need a couple of 7 segment displays).

But keep it up man, what a great project.

[Reinhard]

Originally Posted by blackwasp

Wow, this is very neat and quite handy I must say. You could even retrofit a similar one on the car bumpers itself giving you a front and year parking sensors with realtime range display (you might need a couple of 7 segment displays).

This was the exact thought I had when I was reading the thread earlier. That instead of placing it in the parking, how about placing it on the car itself, so that it can work anywhere outside also when parking at different places with small clearances.

But then I realized if one doesn't have these items already available, installing readily available front and rear parking sensors might be a simpler thing for general public.
Yet - for a dedicated home parking solution - this is simply fantastic. You have the liberty to customize and precisely set the distance for warning & you can keep it quite tight since its a standard parking slot and you know the margins well. Its almost like the landing light signals for carrier borne planes.

Originally Posted by jothishX

Nice project. I would suggest (once the lockdown ends) to get the cheaper JSN-SR04T sensor (about Rs. 500) instead of the Maxbotix sensor (about 8k). The sensor is the same that is used in cars and is also waterproof. I've been using one for measuring the water level in my overhead tank and has been running for two years after being in the sun and rain.

Wow a radar sensor for water level? Why didn't you simply go for a conductivity based sensor instead? Would have been terribly cheap & easier in comparison I think?

[palsaumik]

This is excellent engineering stuff and I love such projects.

What sort of coding is needed to make this stuff work? Some technical details will be helpful.

[jothishX]

Originally Posted by Reinhard

Wow a radar sensor for water level? Why didn't you simply go for a conductivity based sensor instead? Would have been terribly cheap & easier in comparison I think?

The benefits of an ultrasonic sensors are many:
Need to dip at least 6 electrodes in water to detect water level at different levels 0, 25, 50, 75, 100% etc. The electrodes will get corroded over time due to running current. Also, electrolysis will take place due to dissolved salts and will foul the water.
The ultrasonic sensor on the other hand is contact-less and gives precise measurement, not in steps. Like this

I've mounted it on the tank lid.

[jnanesh]

The system would be an ultrasonic one, since radar works with radio waves which are electromagnetic waves, while ultrasonic waves are sound waves/pressure waves.

Don't mean to be nitpicking,the system by itself is a great idea, kudos!

[chiro3110]

Originally Posted by jothishX

Nice project. I would suggest (once the lockdown ends) to get the cheaper JSN-SR04T sensor (about Rs. 500) instead of the Maxbotix sensor (about 8k). The sensor is the same that is used in cars and is also waterproof.

Thank you very much for the recommendation. I was looking for alternate cheaper ultrasonic sensors to have a more economic built. Now that you have confirmed it's durability it would be a safe choice. In India, the JSN sensor is available for around 800-900 INR. Aliexpress quotes cheaper but with shipping and customs it would probably go a bit higher. I had already bought this Maxbotix sensor for another project which required more precision, but unfortunately that assignment did not see the light of day!

Originally Posted by blackwasp

Wow, this is very neat and quite handy I must say. But keep it up man, what a great project.

Thank you very much.

Originally Posted by Reinhard

This was the exact thought I had when I was reading the thread earlier. That instead of placing it in the parking, how about placing it on the car itself. Yet - for a dedicated home parking solution - this is simply fantastic. Its almost like the landing light signals for carrier borne planes.

The comparison was very flattering when comparing to landing light signals .

Yes, agreeing with you and @blackwasp, with the availability of front parking sensors (with the distance display) it would have been a better choice. Actually this was like a hobby DIY to keep occupied during this lockdown period. Just wanted to be engaged. TBH, I hardly use it while parking the car as I have become quite accustomed of the distances by now.

Originally Posted by palsaumik

This is excellent engineering stuff and I love such projects. What sort of coding is needed to make this stuff work? Some technical details will be helpful.

Thanks. To code Arduino the language used is C++. Same syntax albeit some more additional header files. You would need the Arduino IDE which can be obtained from their website. Once the Arduino is connected to PC via USB, the Arduino IDE will detect it and will allow you to upload your codes to it.

Originally Posted by jnanesh

The system would be an ultrasonic one, since radar works with radio waves which are electromagnetic waves, while ultrasonic waves are sound waves/pressure waves. Don't mean to be nitpicking,the system by itself is a great idea, kudos!

Yes, you are right. Probably sonar would have been a better term to use, may be. But normally sonar is associated with underwater systems.

[yash2424]

Awesome, something similar:
https://www.amazon.com/Striker-Adjus...s%2C144&sr=8-4

[ElonSkum]

Originally Posted by jothishX

The benefits of an ultrasonic sensors are many:
Need to dip at least 6 electrodes in water to detect water level at different levels 0, 25, 50, 75, 100% etc. The electrodes will get corroded over time due to running current. Also, electrolysis will take place due to dissolved salts and will foul the water.
The ultrasonic sensor on the other hand is contact-less and gives precise measurement, not in steps. Like this

Would the sensor work equally well, if the liquid were fuel- diesel or petrol , instead of water?

Would these ultrasonic sensors give a more precise reading as a fuel gauge than those based on variable resistor?

[jothishX]

It would work for any liquid. Actually factories handling harsh chemicals like sulphuric acid use ultrasonic sensors to measure depth in the tanks.

These sensors will give a precise measurement, but may spike occasionally if the liquid surface is not stable, or if the soundwave bounces off the sidewalls. All of these have to be normalized in code.