My initial attempts at building an RC boat were a disaster. The first one I built used 433MHz RF modules that somehow worked properly only on land. The moment I placed the boat in the water, the electronics would go crazy (probably due to EM noise) and I had to dive in to save the boat. So I decided my next one would use 2.4GHz RF modules, and this post here is about my successful attempt 😀
I used a 2 liter Pepsi bottle as the boat hull. For the RF link, I used nRF24L01+ RF modules , and the friendly Arduino as the boats brains.
The boat uses two small DC motors to provide differential steering and propulsion. The propellers are made using plastic from SIM card packaging ( Tip: You can use heat from a hair dryer to shape the propellers). The motors are secured using a cable tie and hot glue. For water proofing, I used a silicone gasket maker along with hot glue to plug the holes.
To control the boat, I built a joystick controlled transmitter unit using another nRF24L01+ module and my minimal Arduino.
Fritzing sketches and schematics of the transmitter and receiver units (click the images to zoom in):
And finally, the Arduino code on github.
- You might have to insert capacitors at the motors and nRF24L01+ module (see schematics) to prevent erratic behavior caused by EM noise.
- I used a li-ion battery without protection circuitry for powering the motors. Using the protection circuitry caused the batteries to unexpectedly go in to low power.
- The weight of my Li-ion batteries helped submerge the boat to a desired extent and provided a center of gravity (for stability).