Method for Reading Sensors and Controlling Actuators Using Audio Interfaces of Mobile Devices

Abstract

This article presents a novel closed loop control architecture based on audio channels of several types of computing devices, such as mobile phones and tablet computers, but not restricted to them. The communication is based on an audio interface that relies on the exchange of audio tones, allowing sensors to be read and actuators to be controlled. As an application example, the presented technique is used to build a low cost mobile robot, but the system can also be used in a variety of mechatronics applications and sensor networks, where smartphones are the basic building blocks.

Increasing Students' Interest With Low-Cost CellBots

“…For example, it is possible to use the mobile device's compass or gyroscope to control the robot heading direction and curves [9]. Moreover, the accelerometer and computer vision can be used to compute odometry by using visual odometry techniques and to implement simultaneous localization and mapping (SLAM) techniques.…”

“…One solution that is gradually gaining more attention is the use of smartphones as the main controllers of low-cost robots [7]- [9], [19]. As mobile phones have several features and sensors directly useful for robots, operating them as a robot's main processing unit is an interesting option.…”

“…Moreover, the accelerometer and computer vision can be used to compute odometry by using visual odometry techniques and to implement simultaneous localization and mapping (SLAM) techniques. Computer vision can also be used to replace ultrasound and infrared distance sensors with good precision [9].…”

“…A reliable solution is to use dial tone multifrequency (DTMF) audio signals to easily control up to four dc motors using stereo audio interfaces of mobile devices [9].…”

“…More than 70% said that they would spend their money to build their own robot if it could be used in several courses. The main contribution of this paper is the application of a flexible and low-cost robot adapted from a previous work [9], disseminating the use of robotics for educational purposes. Also provided are a survey of state-of-the-art low-cost educational robots and an assessment of Brazilian students' interest in robotics-related subjects in this low-cost context.…”