I have a houseboat docked in a covered slip. I am looking for a product that will continually measure the distance between the top of my boat to the ceiling of the dock roof to help me know when/if the roof of the boat is getting too close to the marina dock roof. I.e., if there is a heavy rain I may need to move the boat to an uncovered slip to ensure the boat does not hit the dock roof. Does anyone know of a product that would be able to give me a continual reading that I can check? It would be even better if I could check these readings through a mobile app or software program too.
Any direction for a product like this would be greatly appreciated!!
Hello @houseboat_girl and welcome to the RobotShop community,
You could use an ultrasonic distance sensor for that, and since we are talking about a boat it would be nice if it is waterproof/weatherproof, model. This device will allow you to measure the distance from the boat to the roof or vice versa, depending on where you want to place it.
To read the data you will need a microcontroller, a great option is an Arduino because you’ll be able to find lots of tutorials with it. To be able to send this information to your phone you will also need a Bluetooth/Wifi module, or you could simpy get a microcontroller with Bluetooth/Wifi like an ESP32 or ESP8266, and to power everything a battery.
I hope this information can help you out!
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Thank you so much for this information, I will check out your recommendations!
Thanks again. 
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This module can be used to visually see the distance that the Ultrasonic module senses.
No microprocessor required.
You plug the Ultrasonic into this device and it then gives a continuous reading of the distance the sensor is detecting, on the LED display. Readings are performed once every second. It has an onboard chip that is performing the triggers and sensor conversions from the HC-SR04. If the waterproof version said earlier is used, this module can be mounted inside of the cabin with the connections routed to the sensor outside.
If mounted on the ceiling of the cabin interior, you could just look up at the ceiling and see the status of the sensor on the roof, outside. The lower the value to zero, the closer the exterior roof is to the slip root.
Take an old phone wire which has the four wires already in it, cut off the RJ11 connector from each end and drill a small hole to run thru the roof (seal it up after) and an unused cell phone adaptor to supply the power to this device, which will then power the SR04 thru the wire run. This module does all the work and displays the distance a human can read (in Millimeters).
Hope this Helps!
Acigan International
For users with coding skills, the device can be attached to a uProcessor and its readings are output on its TX pin, every second. Just read the UART port. No math involved. The transmitted data IS the reading, once per second. Eliminate all that logic doing the triggers and math at the sensor from your code and just get the latest value directly from the comm port and act upon it.
There are times when hardware does things better then software. This is one of those times.
Acigan International
Design Division
