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Using the MSP-EXP430FG4618 Development Tool establish a data exchange between the MSP430FG4618 and MSP430F2013 devices using the SPI mode. The MSP430FG4618 uses the USCI module while the MSP430F2013 uses the USI module.

Laboratory communications: lab2 - echo test using spi

Introduction

The MSP430 contains built-in features for both parallel and serial data communication. This chapter describes the operation of these peripherals, and discusses the protocols, data formats and specific techniques for each type of data communication.

The communication modules available for the MSP430 family of microcontrollers are USART (Universal Synchronous/Asynchronous Receiver/Transmitter), USCI (Universal Serial Communication Interface) and USI (Universal Serial Interface). These provide asynchronous data transmission between the MSP430 and other peripheral devices when configured in UART mode. They also support data transmission synchronized to a clock signal through a serial I/O port in Serial Peripheral Interface (SPI) and Inter Integrated Circuit (I2C) modes.

Overview

This laboratory explores the USCI and USI communication interfaces in SPI mode. The MSP430 devices included on the Experimenter’s board will exchange messages between themselves, one being the MSP430FG4618 (master) that will control operation of the other MSP430F2013 device (slave). The master, by reading the current state of the slave, will drive the slave to the new desired state, controlling its activity. In this particular case, switching the state of LED3 will be implemented.

Resources

This laboratory uses the USCI module of the MSP430FG4618 device and the USI module included on the MSP430F2013. Both units operate in SPI mode.

The Basic Timer1 of the master device is programmed to switch the status of the slave device once every 2 seconds.

The slave is notified of the arrival of information through the counting end interrupt of the USI module.

The resources used are:

- USCI module;

- USI module;

- Basic Timer1;

- Interrupts;

- I/O ports.

Software application organization

The software architecture for this laboratory is shown in Figure 1.

The master unit is composed of two software modules ( Lab2_Comm_1.c ):

- The "Main master task" module contains the operation algorithm of master unit;

- The "ISR Basic Timer" module wakes the "Main master task" once every 2 seconds.

The slave unit is also composed of two modules ( Lab2_Comm_2.c ):

- The "Main slave task" module contains the operation algorithm of the slave unit;

- The "USI ISR" module reads the data received, prepares the USI module for new reception and wakes the "Main slave task" to execute the algorithm associated with the reception of the new command.

Software architecture

System configuration

Usci_b (master) control registers configuration

The SPI connection will operate in the following mode:

- Clock phase ->Data value is updated on the first UCLK edge and captured on the following edge;

- Clock polarity ->the inactive state is low;

- MSB first;

- 8-bit data;

- Master mode;

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
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cm
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2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
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Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
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Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
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"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
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A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
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Source:  OpenStax, Teaching and classroom laboratories based on the “ez430” and "experimenter's board" msp430 microcontroller platforms and code composer essentials. OpenStax CNX. May 19, 2009 Download for free at http://cnx.org/content/col10706/1.3
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