Water Warning -- a Device to Save Your Boat
Introduction: Water Warning -- a Device to Save Your Boat
If you are a boat owner there is solid comfort in finally getting the boat on dry land. It can't sink there. Everywhere else it faces a constant battle to overcome the tendency to slip under the waves and disappear. During the winter here in Alaska our local Whittier harbor has its share of boats that suddenly and for mostly the commonest reasons slip away into the frozen dark; the only remaining signs are its lines still gamely tied to the dock. The one at the end of our dock was gone a couple years ago when I was visiting to scrape the snow off my own boat. The diver, who was half into his dry suit smoking a cigarette about to try raising the boat with inflatable bags, replied to my question of what caused the mishap with a ¯\_(ツ)_/¯. The statistics are quite clear: 2/3 of boats go down not supporting our president in a flotilla but quietly and inexplicably at their moorings. The answer is there are a lot of holes in the bottom of your boat. For those not familiar most are associated with the necessary functions of getting rid of poop, cooling the engine, air conditioning, electronic sensors, exhaust, sink drainage and the drainage of the deck. At any time these along with their associated tubing can spring a leak. Bilge pumps and their redundancy can keep it going for a while but eventually it sinks. We rely on either a passing good Samaritan or the call at two in the morning that someone has noticed that your boat is gone.
This water warning project is a simple device that will notify you with a text message and email if a float switch detects a bad situation. It works off a cell phone mediated microcontroller that is powered for years on a battery without need for attachment to the boats electrical system. The service (Hologram) has a minimal cost of $18 a year for the cloud connection and about $60 to build the actual unit-- and anyone can build it. I also propose a LORA version of the same system that could protect a whole harbor for only $25 a boat.
Step 1: Gather Your Materials
This project is really simple and requires very few items to make it work. If you are new to microcontrollers and electronics and just want to build it to protect your boat you can do this one easily.
1. Hologram Account--Sign on to Hollogram and get an account. They will send you a free SIM card that will fit the Microcontroller listed below. 537
There is a certain regimen to registering your SIM card on the site but it is easy and the site has very good instructions.
2. ARDUINO MKR GSM 1400--https://store.arduino.cc/usa/mkr-gsm-1400 The current price is $68 but I have seen it be as low as $55 not sure what causes it to vary. Not available ( that I know of) from suppliers in China. There are many GSM boards but most run afoul of the lack of infrastructure to support them -- retired 2G and 3G networks. This board really works instantly and is very well built and the Blynk app supports it. Make sure you get the antenna made for it!
3. 18650 Battery--generic $6.00 Don't undersize this battery! It takes a lot of power to do the cell phone call.
4. Float Switch--Anndason 6 Pieces Black Water Level Sensor Aquarium Tank Side Mounted Horizontal Liquid Float Switch $2.00
5. JST PH 2-Pin Cable -100mm --$1
Step 2: 3D Print It
The case is very basic and can be printed without supports in PLA. There are only three pieces to print. The base which is designed to fit the Arduino board very securely. The cover which has three holes: one for the charging/programing mini USB on the board, one for the antenna and one for the wires from the float switch. The support structure for the float switch can also be printed without supports and is sized for the nuts on the float switch. If you don't have a 3D printer you can honestly just put the Arduino in any plastic case that will fit it and the 18650 battery. The float you can just attach to anything as long as it supports it in your bilge. The antenna will just be attached to wall adjacent to the Arduino.
Step 3: Wire It/Build It
Wiring this does not require any wiring diagram unlike most of my projects. But it's simple so anyone can build it. The float switch just turns on the computer so that it runs the computer program that sends your text message. The 18650 battery you ordered hopefully has red and black wires attached so it will make it easy. 33