Arduino GPS Drone RC Boat

12.10.2018: I am in the progress in creating an auto-piloted, Arduino Mega-controlled, GPS and camera-equipped drone boat. Control is via 433 MHz serial modules to a c# windows forms remote application.

Steps Completed So Far

Building the boat and tasting some on the lake without GPS. Decided to share the project here.

15.10.18: Due to the boat being very low in the water, I decided to go for a bigger boat and also remake the electronics.

Now the plan is to have the following outline:

Arduino Mega. PWM control of the 2 motors by L298N (shield) for rudderless steering and propelling (tank like control).

01.11.18 After some trial and error soldering I have a prelimary circuit diagram

Description is as follows:

We have 4 separate power rails for 12V, 5V, 3.3V permanennt and 3.3V switchable.

Note that 12V means unregulated power from the battery, so it can also be another voltage up to 15V.

Power rail 12V from battery:

- feeds the 298N breakout board and thus the electrical drives of the boat and all
the buck converters

- will drop over time when the battery gets depleted

Power rail 5V

- regulated by LM2596 buck converter

- Feeds the arduino mega with constant 5V

- Feeds the logic level converter with the 5V voltage

Power rail permanent 3.3V

- regulated by 3.3V buck converter

- feeds the 3.3 V GPS, MPU9250 9DOF
accelerometer/compass and BMP280 pressure/humidity/temperature sensor and the 3.3V side of the logic level converter

Power rail switchable 3.3V

- same buck converter (800mAmps) as the permanent 3.3V rail

- can be switched on/off by tip122 npn transistor (didnt have a mosfet)

- tip122 switches through new ground wich is connected to 3.3V buck converter

- this 3.3V buck converter can thus be switched on and off via tip122 (gate connected to arduino digital pin using a 10kOhm resistor) and powers the camera and hc12 radio module

Other items in the circuit:

Mechanical switch:

Mechanical switch to conveniently turn on and off the whole electronics.

Voltage devider:

Then we have a voltage devider to measure the battery voltage with the Arduino. This voltage devider will turn 15V to a safe 5V which can be read by the arduino analog input pin. I used 20kOhm and 10 kOhm, see in the shematics.