Water Gun Robot

Michael Winter’s Squirt is an autonomous robot which can communicate with an Android phone. Optionally, the phone can be used as a controller to drive the robot. Squirt’s purpose is to water plants and chase away raccoons. It’s also a technology demonstration to prove the feasibility of using a smart phone to control small irrigation and well systems.

Squirt can either be in guard mode or phone control mode. In guard mode it searches for moving objects and squirts them. In phone control mode it is driven like a RC car. Steering can be by software joystick or by tilting the phone in the direction the robot should go.

The big red dot in the middle is a software joystick for driving. The red lines indicate distance senor values from the robot. If the green circle icon is pushed, the big red dot turns blue and becomes a pan/tilt joystick for the water gun. The orange circle with red dot is the water gun trigger.

Squirt can also be controlled by SMS text message from any cell phone. This is accomplished by using the Android phone to relay the message to the robot. For instance, if you send my Droid phone a message where the first character is a period, it will command the robot to fire the squirt gun.

The robot has a timid personality. It verbally comments on external events and on the human’s driving skills. In general, Squirt is wary of things sneaking up behind it.

The water gun is a slightly modified SIG SAUER STR70 Saturator electric water gun. It shoots 4 “bullets of water” every second; range is 6 meters. The amount of water is small and unlikely to damage even the most fragile of plants. Interestingly it features “realistic sound”. To me it doesn’t sound so much like a machine gun but more much like a powerful electric water gun, which it is. The noise is loud, which hopefully can scare raccoons away from tomato plants. How Squirt Works: Squirt uses 3 onboard processors plus a processor in each servo. The master processor is an Arduino Mega which is used for AI, navigation and as a master controller for the sub systems. The second processor is an ARM 9 board for controlling the high speed communications to the servos, last is a graphic processor for the OLED Display.

The Arduino Mega sends and receives data from the Android phone via blue tooth. The Arduino is constantly sending sensor and AI information to the phone. The robot receives driving, servo controlling and mode setting data from the phone. Personality functions are carried out both on the phone and the robot.

The water gun fires by using a relay to bypass the trigger circuit. A 3 color 1 watt LED has been mounted on the barrel to display status of the mood of the gun. Red, of course, means its upset and likely to fire shortly. Summary: Squirt demonstrates that a smart phone and a robot can work together to accomplish tasks. The next step is to design an simple irrigation system based on the technology, get philanthropic funding and hopefully help grow food.

Check out more on the construction overview and videos page for Squirt.

Fun Video:

Contact info for Michael Winter: robotmike@comcast.net