• results
  • appendix
  • future work
  • analysis
• user interface
  • control protocol
  • GUI
• firmware
  • extra functionalities
  • height control
  • motor control
  • wireless communications
  • UART communications between subsystems
• hardware
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Contents:

Objective | Scope | Related Work

Introduction

In CSE 466: Software for Embedded Systems, one of the main focuses has been developing embedded software that integrates knowledge of specific development environments with other related topics to develop complex systems of multiple interacting devices. Over the course of the class, new series of concepts were introduced through the implementation of components specified in each weekly lab including selected embedded algorithms, useful communication protocols, and power management techniques. Fundamentally, these labs were designed to be cumulative in nature, building up students’ knowledge and experience to the current final project. | Back to contents |

Objective

The desired objective for the final project is to design and implement a working blimp bot, a wireless communication protocol to communicate with the designed blimp, and a user interface that allows users to utilize the given protocol. Ultimately, the project will produce a working blimp system that includes a flying control protocol as well as other features utilizing sensing and lighting equipment built onto the hardware. A wireless communication interface utilizing low-power RF signals to send and receive data will also be set up within this project. Lastly, a user interface will be implemented in order to initiate and facilitate direct communication with the built blimp module. | Back to contents |

Scope

As defined in the respective lab write-ups, there were considerable amounts of requirements that need to be met in the actual project design. At the very top of these requirements was the demand to include several commands within the user interface and blimp bot module including a start/stop command, a low battery monitor mechanism, motor control, and IR sensing. Following from this, there were three defined requirements within the blimp module design that had to be implemented, one of which included the usage of a movement system that interprets and changes the blimp’s position within a three-dimensional space. Another requirement included the specific usage of IR photosensors and LEDs instead of electric fields (used in previous labs) for proximity sensing and the height control feature. The other requirement involved using pulse-width modulation alongside the motors to control their individual timing and speed. Stricter requirements had to be met when designing the wireless communication protocol: within that particular specification, wireless communication was defined to be asynchronous (or full-duplex, meaning that communication happens simultaneously instead of in a “stop-and-wait” fashion). In addition, only a universal asynchronous receiver/transmitter (UART) was specified as satisfactory for data relay between the wireless chips and the computer or blimp. Lastly, the wireless connection created had to be established through a static link, forcing the wireless communication to only occur between the two defined wireless chips.

Wireless communication calls and handling was all handled through Texas Instruments’ (TI) SimpliciTI API (which was already setup on the lab stations). In addition, almost all hardware provided for this project consisted of TI microcontrollers or TI compatible equipment. Due to the versatility of the blimp bot module to include multiple TI components, the amount of desirable features that can be added to the overall functionality of the blimp ranges near infinite. However, in response to the specification changes made throughout the final project, the blimp bot had huge constraints, the biggest being time restrictions. In response to that, the blimp did not include the on-board compass heading feature proposed at the beginning. In addition, the mapping of linear data from the IR sensors was not included within the final analysis of the IR proximity sensing as this feature required unusual calibration of each sensor or the usage of a look-up table (LUT) based mapping of linear interpolated values, both which were not believed to be efficient within the overall timing of the blimp’s clocking unit. | Back to contents |

Related Work

The final project builds upon the final project for the previous CSE481 Robotics Capstone led by Dieter Fox. Similar to this project, the blimp bot project required manual user control of the blimp position as well as a wireless communication protocol and user interface for users to initiate commands on the blimp. However, due to the nature of the class being a Capstone course, the limitations of the blimp hardware were not as restrictive in comparison to the current final project. In addition, the Capstone project utilized different methods of wireless communication (Bluetooth) and hardware to run and power the blimp. Examples of this include a different balloon material, more powerful motors, and path-finding algorithms for autonomous control of the blimp. | Back to contents |