The PoolSkimmer project takes a standard RC Boat (e.g. the Nikko Sea Racer) and transforms it into a semi autonomous drone that can clean debris from a the top surface of a pool. This is an Arduino based project that uses standard motor controllers to take over the speed and direction of the boat. A sonic sensor is used to detect pool walls and ladders so the Pool Skimmer can change direction to avoid the object.
Heres a brief list of the parts used:
- Nikko Sea Racer RC Boat (or any rc boat that does NOT have an EXC controller)
- Aruduino UNO (Any Ardino that can mount the LD293 should do)
- Any Arduino Uno case/enclosure
- Arduino Motor Shield (LD293)
- HC-SR04 Sonor Sensor
- Breadboard jumper for Arduino
- 8" of 3/4" CPVC piping
- 4 of 45 degree CPVC connectors
- 4 of 90 degree CPVC connectors
- 1 Pool noodle with 3/4" center (should fit snuggly over the CPVC pipe)
- Replacement head for pool skimmer (rectangular model)
Approximate cost of the project: $120, should be less that $40 if you have an old RC boat that can be sacrificed for the project.
The frame needs to hold the skimmer and harness the boat so it can move as a single unit. The frame width should be at least two inches wider than the skimmer (on each side) to allow for the net to drag freely. The length of the frame should be at least 4 inches longer than the length of the net plus the length of the RC boat. The height of the frame should allow the back bar to secure to the boat. In the case of the model built for this project the dimensions were approximately 18 in x 24 in X 3 in. You may have to make adjustments for the exact size depending upon the boat model and skimmer net used. Note the use of the 45 degree connectors. This helped with the buoyancy and strength of the frame , but was not really necessary.
Cut 2 pieces from the pool noodle to fit over the frame side peices. This will help maintain buoyancy when making turns and resisting waves in the pool. When ready use CPVC cement to glue the pipe pieces together to form the frame.
The skimmer can be secured to the frame using 2 inch machine bolts. Drill a hole for the screw that is slightly larger than the screw used. The boat can be attached using wire ties. This allows for easy removal when maintenancing the boat.
Remove the top of the RC boat. The Arduino board will need to be mounted in a Arduino Case (case bottom only) and placed between the propeller motor and the propeller. You may have to use standoffs to prvent the shaft from rubbing in the Arduino case. For the Sea Racer there is sufficient room for Arudino Case for the top of the RC Boat to be placed back on. The motor shield mounts right on top of the Arduino Uno. This prevents the case top from be used. The LD293 pins line up with the Arduinos and some of them pass though for easy connections. It should look like this when the motor shield is mounted on the Arduino .
A Simple coat hanger can be used to mount the sonar sensor. Remove the black plastic rails on the top of the RC boat.The end of the coat hanger will fit snuggly into the rail holes on both sides of the boat seats. Bend the hanger so that the top of the hanger is about 8 to 10 inches over the boat surface. Use wire ties to secure the sonar sensor to the hanger (see picture on top of the page). Connect four of the jumpers to the sonic sensor pins. Label the ends so they can be easily connected later on (the sonic sensor has pin names on its circuit board).
The 6 batteries that power the RC boat are sufficient to power this project (including the Arduino board). Clip the end off of two of the breadboard jumpers (preferably one red and one black jumper) and solder the red jumper to the positive side of the battery terminal and the black the negative (you may have to remove the battery pack from the boat housing).
Unfortunately this project requires cutting wires on the RC boat. You will need to determine the wires that control the propeller motor and the rudder motor. This is easily accomplished by opening the boat and tracing the wires from the RC receiver (the circuit board in the picture) to the motors. Disconnect the two wires going to the Propeller motor (Black motor in the center of the boat) using a soldering iron. Repeat this for the wires going to the rudder motor as well. Label the wires so you can easily connect them in the following steps.
Connect the jumpers from the battery to the Motor sheild as shown in the wiring diagram (red to Vcc and black to ground). The jumper should slip snuggly over the power and ground pins. The Propeller wires should be connected to M1 and M2 on the motor shield as shown. There may be a little trial and error to determine forward and backward. Repeat the same for connecting the rudder pins to M3 and M4.
Connect the jumpers from the sonar sensor as indicated in the wiring diagram. Note that power and ground can be connected to Vcc and ground of the LD293 motor shield board.
Lastly connect the power and ground pins from the battery to the main power terminals on the LD293 motor shield board.
Once this repo has been cloned, an arduino project can be created using the Arduino IDE . The software can be downloaded into the Arduino from the IDE using a simple USB cable. Once the software is loaded, power off the Arduino and it should be ready for it maiden voyage.