Part 1 - Overview and tools

The embedded systems (ES) formation require a broader set of knowledge, abilities and skills including informatics and electronics concepts in order to develop highly creative and imaginative applications based in analytical studies. Moreover, in an effort to improve the education quality it needs to be followed with intense hands-on laboratories. This paper presents a new approach for embedded systems courses appropriate for both high school and undergraduate classrooms, that has been conceived and designed to accomplish these goals, while motivating and equipping this next generation of engineers to rise to future challenges. The course structure was defined in order to be easy to understand and provide a logical flow along the topics, as it mostly progresses from simple topics to more advanced ones. The developed materials include slides for class room teaching, explanatory documents for student and educators future reference, laboratories, tests, programs and application examples after each chapter. Each module is dedicated to a specific aspect of the MSP430 device, including the description of a range of peripherals. This is the first part of the paper presenting the outline of the course. Particularly, this paper identifies the course need, presents its structure, and the initial subjects covering an introductory overview in logic design and embedded processors and a description of the available software and hardware development tools for the MSP430.info:eu-repo/semantics/publishedVersio

Processor, Payload, and Power Subsystem Development of the MISSat-1 CubeSat

This thesis details the development and programming of the processor subsystem, camera payload, and power subsystem of the Mississippi Imaging Space Satellite (MISSat-1). An overview of the hardware and software considerations necessary for the processor subsystem is discussed. An explanation of microcontroller uses as well as real time operating system fundamentals is also presented as it relates to MISSat-1. The subsystem deals with varieties of peripheral integration and communication standards among devices. The camera graphical user interface (GUI) was expanded with the addition of functions that improve CubeSat image handling. Additionally, image processing techniques and algorithms are considered to improve CubeSat images. This work continues the camera payload work undertaken by University of Mississippi electrical engineering students from previous years. This paper will then discuss the design and analysis completed thus far for the power subsystem of the MISSat-1. Such topics will include an in-depth solar panel investigation, which will lead to the selection of the solar panels that will be used on the MISSat-1. The solar panel selection, along with the other chosen subsystem components, will allow for the formation of the power budget, which shows the breakdown of power usage for each subsystem. The power budget will then be developed into a Matlab GUI. Finally, the power budget will be further analyzed by comparing it to other satellite projects

Microcontrollers for Mechanical Engineers: From Assembly Language to Controller Implementation

This paper describes the evolution of a graduate and advanced undergraduate mechanical engineering course on microcontrollers and electromechanical control systems. The course begins with developing an understanding of the architecture of the microcontroller, and low-level programming in assembly language. It then proceeds to working with various functions of the microcontroller, including serial communications, interrupts, analog to digital conversion, and digital to analog conversion. Finally, the students learn how to characterize first and second order systems, and develop and implement their own controllers for a variety of electromechanical systems. The course takes the uncommon approach of teaching assembly language programming to mechanical engineering students, with the students using assembly language programming for approximately half of the course and the remainder using the C programming language. The authors believe that this approach helps students develop a better understanding of the architecture of the microcontroller and low-level routines found in embedded control applications. The course provides a bridge between traditional mechatronics courses that focus on electronics and interfacing, and lab-based control courses that use turnkey data acquisition systems and graphical programming tools such as Simulink or LabVIEW. The course has existed for over two decades, using a variety of microprocessor and microcontroller platforms. After evaluating numerous alternatives, the course was recently updated to use a 32-bit ARM Cortex-M3 microcontroller evaluation board from STMicroelectronics paired with custom interfacing circuitry. This platform was chosen not only for more modern microcontroller technology, but also for the availability of free development tools and very inexpensive evaluation boards. This allows the students to write and test their programs outside of scheduled lab times, along with the ability to cost-effectively utilize microcontrollers in future projects

Implementation of a MSP430-based digital thermometer using the slope ADC of the timer port module

This report describes the slope A/D measurement of a resistance and the ease with which it can be applied to MSP430 microcontrollers. It describes a digital thermometer design that uses the slope ADC capabilities of the Timer Port module on the MSP430x3xx microcontrollers. It is used more generally as a reference on how to connect resistive sensors and reference resistors to the Timer Port module. All MSP430x3xx devices include the Timer Port module. The module allows several resistive sensors and reference resistors to be connected in an application. Unused module pins can be used as independent outputs. Slope A/D conversion is an analog-to-digital conversion technique that can be implemented with a comparator rather than a standalone ADC module or device. The technique is based on the charging/discharging of a capacitor with a known value. The number of clock cycles necessary to discharge the capacitor is then counted. Longer discharge times indicate larger voltages. The voltage is derived from the discharge time using the standard equation for capacitor discharge. In addition to digitizing voltages, a variation of the technique can be used to measure resistance. This is valuable in measuring any component that can have varying resistance, such as potentiometers and various types of transducers. Unlike voltage measurement, where the key relationship is between voltage and time while the resistance is constant, the key relationship in resistance measurement is between resistance and time, while the initial voltage remains constant. The R-relationship is linear, which means the calculation is easier and less- costly to implement in a microcontroller than for the exponential V-t relationship. The thermometer has been simulated by using a variable resistance instead of a thyristor. In addition care has been taken to optimize the power consumption by forcing the microcontroller to several low-power modes during the operation. The combination of the Timer Port module, the 16-bit CPU, and the ultra low power design provide unmatched MIPS per watt performance. The set up can be extended to provide a low power thermostat

Wireless sensor node design for heterogeneous networks

Two complementary wireless sensor nodes for building two-tiered heterogeneous networks are presented. A larger node with a 25 mm by 25 mm size acts as the backbone of the network, and can handle complex data processing. A smaller, cheaper node with a 10 mm by 10 mm size can perform simpler sensor-interfacing tasks. The 25mm node is based on previous work that has been done in the Tyndall National Institute that created a modular wireless sensor node. In this work, a new 25mm module is developed operating in the 433/868 MHz frequency bands, with a range of 3.8 km. The 10mm node is highly miniaturised, while retaining a high level of modularity. It has been designed to support very energy efficient operation for applications with low duty cycles, with a sleep current of 3.3 μA. Both nodes use commercially available components and have low manufacturing costs to allow the construction of large networks. In addition, interface boards for communicating with nodes have been developed for both the 25mm and 10mm nodes. These interface boards provide a USB connection, and support recharging of a Li-ion battery from the USB power supply. This paper discusses the design goals, the design methods, and the resulting implementation

Wireless Sensor Mesh Network for Irrigation Systems

Pepper Oak Farms, a company that grows their own olives for olive oil and has approximately 40,000 olive trees, is in need of an efficient way to monitor the soil and atmospheric conditions that are critical to the cultivation of their trees. The company at the moment only has two sensors and has to manually place the sensors at different locations to collect data on soil moisture and temperature. This is expensive, time consuming, and a lot of effort on the owner’s part to go out on the fields to collect this data. As a solution, the company would like to create a wireless mesh network with different nodes throughout the land to monitor and collect data from the sensors. The project goals are to implement this wireless mesh network with enough nodes in the network to cover most of the area on the land and for the project to be self-monitored. To help cover costs, we will be using modules that use Zigbee IEEE 802.15.4 wireless protocols and standards which are used for low power consumption and have a range of up to 100 meters. The modules will be interfaced with Texas Instrument’s Tiva C microcontrollers that will collect the output of the sensors to be later transmitted to the home network

SMaRT: Small Machine for Research and Teaching

We introduce SMaRT, a 16-bit single-cycle RISC-type processor with 16-bit-wide instructions. SMaRT features the novel concept of 2.5-address instructions to avoid the data loss that inherently exists in 2-address processors. Additionally, SMaRT’s short-branch instructions take advantage of the temporal locality of reference in accessing the upper or lower halves of the CPU’s 16x16 orthogonal register file. This allows SMaRT to significantly extend the range of the short-branch instructions. We show that these novelties are achieved at almost no performance cost and negligible hardware cost. SMaRT has four operation modes, namely Single-Step, to execute one instruction at a time, Manual, to display and inspect individual locations of data memory, Run, to run the whole code nonstop, and Init, to copy a read-only memory to the data memory for initialization purposes. We also implement and present an input/output port and a sorting coprocessor, and then hook it up to SMaRT through the port as an example. We have successfully synthesized the combined SMaRT and the sorting coprocessor into the Altera Cyclone II FPGA chip, and tested them

Internet based data collection and monitoring for wireless sensor networks

Thesis (M.S.) University of Alaska Fairbanks, 2007The omnipresence of the Internet and the advances in integrated circuit technologies has expanded the potential modes of communication and data collection. Adding Internet capabilities to any electronic device greatly extends the device's user interface, allowing the user to remotely configure and monitor the device over the network through the embedded web server. The embedded web server is expected to establish two-way communication and serve dynamic web pages using very limited resources. We adapted an existing embedded web server to allow remote control and monitoring of wireless sensor networks (WSN). This required establishing an interface to the WSN and developing firmware and user programs to communicate with the remote client. An interactive and flexible web-based user management interface is developed to allow the two-way interaction between the remote user and the wireless sensor network. The embedded server generates email alerts to the administrator about critical issues in the WSN, provides secure access to the WSN control modules, etc. Two embedded web servers are developed using different hardware platforms. The first solution is a low cost, energy efficient solution with somewhat limited functionality. The other uses a more powerful microcontroller-based platform and implements a fully-functional, dynamic web server with multiple web pages.1. Introduction -- 2. Embedded web server -- 3. Related studies -- 4. MSP430-based Web Server -- 5. Rabbit-based web server -- 6. Conclusion and future work -- 7. References -- Appendix A: TCP/IP protocol frame formats -- Appendix B: Embedded web server snapshots

Using SRAM Based FPGAs for Power-Aware High Performance Wireless Sensor Networks

While for years traditional wireless sensor nodes have been based on ultra-low power microcontrollers with sufficient but limited computing power, the complexity and number of tasks of today’s applications are constantly increasing. Increasing the node duty cycle is not feasible in all cases, so in many cases more computing power is required. This extra computing power may be achieved by either more powerful microcontrollers, though more power consumption or, in general, any solution capable of accelerating task execution. At this point, the use of hardware based, and in particular FPGA solutions, might appear as a candidate technology, since though power use is higher compared with lower power devices, execution time is reduced, so energy could be reduced overall. In order to demonstrate this, an innovative WSN node architecture is proposed. This architecture is based on a high performance high capacity state-of-the-art FPGA, which combines the advantages of the intrinsic acceleration provided by the parallelism of hardware devices, the use of partial reconfiguration capabilities, as well as a careful power-aware management system, to show that energy savings for certain higher-end applications can be achieved. Finally, comprehensive tests have been done to validate the platform in terms of performance and power consumption, to proof that better energy efficiency compared to processor based solutions can be achieved, for instance, when encryption is imposed by the application requirements