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.
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
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.
- 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
- regulated by LM2596 buck converter
- Feeds the arduino mega with constant 5V
- Feeds the logic level converter with the 5V voltage
- 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
- 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 to conveniently turn on and off the whole electronics.
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.