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By jbspfn
I have an old Ford Focus 2005. So it has no sensors what so ever. I want to modernize/upgrade it with new sensors starting with blind spot detection.

I thought your ultrasonic Distance Sensor (HC-SR04) (assuming I can protect the electronic board from weather elements so that only the round opening for sending/receiving ultrasound is exposed) is a good candidate, can these openings get damaged by rain/dust or are they rain/dust proof? The other problem I have with this sensor is that its physical size means that it is hard to make it inconspicuous. Do ou have a smaller ultrasonic sensor?

As an alternative I am thinking of using an infrared proximity sensor. Any suggestions on a small proximity sensor that is weather proof and will work well for blind spot detection?

Sorry, ignore the infra red proximity sensor. After a bit of thinking, I just realized that when raining the infra red light may bounce back when it hits rain drops and create false positives. Maybe a PIR (Passive Infrared Sensor might work) .

Any suggestion from Sparkfun about a good sensor I can use is welcome.
User avatar
By TS-Mark
Hi jbspfn,

The HC-SR04 is not weather-proof in really any way so having it on the outside of a car will almost certainly end up damaging it in some way. Also, a car/road is a very noisy environment so you will most likely get a lot of interference from the sensor causing errors in your range data. We do carry a couple of ultrasonic range finders that are designed for outdoor use: but again, you're probably going to get a lot of noise using those on a moving vehicle so it will not be ideal.

An IR sensor might work but, as you noted, you may have some quirks to work out to reduce false positives. Something like the TFMini Plus could work since it is a ToF sensor and you could work out something in your code that would flag false positives caused by rain and other liquid by creating a minimum read distance to trigger your warning.

A Passive IR sensor might work but you would really need to hone in it's field of view to avoid false positives. If you want to take a look at something like that, the SparkFun OpenPIR would be the best option we carry for this. It's more suited for motion/presence detection in a static area but it might work for your project.

I hope this information helps you get started with this project and decide whether or not SparkFun has the parts you need for it. If you have any other questions about these or other SparkFun parts in your project, let us know and we would be happy to help as much as we can.
User avatar
By jbspfn
Hi TS-Mark,
You are right. The XL-MaxSonar-WR1 and HRXL-MaxSonar-WR probably won't work. I drive a lot with my windows rolled down and the noise from my car and other surround noise even when there is no car in the blind spot is so overwhelming that I think they won't work. I am sure those noises cover the ultrasound spectrum of the sensors.

However I do like the TFMini Plus and I will buy one to test it on my car. Hopefully I can also implement some sort of filters in the code to remove false positives.

The PIR sensor is good and the nice thing about it is that it can sit in the car and look out through a window. Some sedans (like mine) have a small none openable glass covered triangular window at the back (passenger and driver sides) so the PIR can sit there and be protected from weather elements. But again I just have to buy one and test to see if it will work.

Thanks for the suggestions. You have saved me many potential hours of headaches lol.