A high-speed FFT unit based on a low cost digital signal processor

1988 ◽  
Vol 35 (11) ◽  
pp. 1434-1438 ◽  
Author(s):  
P. Tortoli ◽  
F. Andreuccetti
Author(s):  
Markeljan Fishta ◽  
Franco Fiori

Abstract$$\varDelta \varSigma $$ Δ Σ analog-to-digital converters (ADCs) are largely used in sensor acquisition applications. In the last few years, standalone $$\varDelta \varSigma $$ Δ Σ modulators have become increasingly available as off-the-shelf parts. To build a complete ADC, a standalone modulator has to be paired with some advanced elaboration unit, such as a field programmable gate array (FPGA) or a digital signal processor (DSP), which is needed for the implementation of the decimation filter. This work investigates the use of low-cost, general-purpose microcontrollers for the decimation of $$\varDelta \varSigma $$ Δ Σ -modulated signals. The main challenge is given by the clock frequency of the modulator, which can be in the range of a few $$\hbox {MHz}$$ MHz . The proposed technique deals with this limitation by employing two serial peripheral interface (SPI) modules in a time-interleaved configuration. This approach allows for continuous acquisition and elaboration of relatively high-speed, digital signals. The technique has been applied to a case study, and a data conversion system has been practically realized. The performance of the proposed filter is compared to that of a digital filter, present on board a commercial microcontroller, and the results of experimental tests are provided.


2012 ◽  
Vol 49 (3) ◽  
pp. 243-259 ◽  
Author(s):  
Juvenal Rodríguez-Reséndiz ◽  
Fortino Mendoza-Mondragón ◽  
Roberto A. Gómez-Loenzo ◽  
M. Agustín Martínez-Hernández ◽  
Victor H. Mucino

In this article a methodology for constructing a simple servo loop for motion control applications which is suitable for educational applications is presented. The entire hardware implementation is demonstrated, focusing on a microcontroller-based (μC) servo amplifier and a field programmable gate array-digital signal processor (FPGA-DSP) motion controller. A novel hybrid architecture-based digital stage is featured providing a low-cost servo drive and a high performance controller, which can be used as a basis for an industrial application. Communication between the computer and the controller is exploited in this project in order to perform a simultaneous adaptive servo tuning. The USB protocol has been put into operation in the user front-end because a high speed sampling frequency is required for the PC to acquire position feedback signals. A software interface is developed using educational software, enabling features not only limited to a motion profile but also the supervisory control and data acquisition (SCADA) topology of the system. A classical proportional-integral-derivative controller (PID) is programmed on a DSP in order to ensure a proper tracking of the reference at both low and high speeds in a d.c. motor. Furthermore, certain blocks are embedded on an FPGA. As a result, three of the most important technologies in signal processing are featured, permitting engineering students to understand several concepts covered in theoretical courses.


Author(s):  
Hussain Attia ◽  
Ali Sagafinia

This paper presents an electronic design based on general purpose discrete components for speed control of a single phase induction motor drive. The MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse Width Modulation (SPWM) techniques with V/F method based on Voltage Controlled Oscillator (VCO). The load power is also controlled by a novel design to produce a suitable SPWM pulse. The proposed electronic system has ability to control the output frequency with flexible setting of lower limit to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the proposed controller able to control the value of load voltage to frequency ratio, which plays a major parameter in the function of IM speed control. Furthermore, the designed system is characterized by easy manufacturing and maintenance, high speed response, low cost, and does not need to program steps as compared to other systems based on Microcontroller and digital signal processor (DSP) units. The complete proposed electronic design is made by the software of NI Multisim version 11.0 and all the internal sub-designs are shown in this paper. Simulation results show the effectiveness of electronic design for a promising of a high performance IM PWM drive.


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