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Corso di Sistemi in Tempo Reale Laurea in Ingegneria dell‘Automazione a.a. 2008-2009. The dsPic33 and FLEX board. Paolo Pagano RETIS Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy [email protected]. Course Outline (1/2). Second day (24 th ) - PowerPoint PPT Presentation
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The dsPic33 and FLEX board
Paolo PaganoRETIS Laboratory,
Scuola Superiore Sant'Anna, Pisa, [email protected]
Corso di Sistemi in Tempo RealeLaurea in Ingegneria
dell‘Automazione a.a. 2008-2009
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Course Outline (1/2)
• Second day (24th)• FSM implementation in C (slides by prof. Di Natale)• A case study• Real Hardware demonstration
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Outline
• Introduction to the FLEX board• A FSM instantiation on the FLEX
• Visit the web site:
http://feanor.sssup.it/~pagano/personalWEB/courses.htm
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FLEX
idea:cheap, small, easy-to-use evaluation boards
Typical applications:• industrial sensing and control• small robots• wireless sensor networks• demo boards for university labs
embedded boards
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add-on boards
1 - 2.54mm pattern2 - 2.54mm alternate
pattern (RJ45 / RS232 connectors)
3 - 1.27mm pattern (SMD components)
4 - 5.08mm pattern (clamps)
breadboard
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add-on boards
1 - Serial port 2(RS232 / RS422 /RS485 / TP-UART)
2 - Serial port 1(RS232 / RS422 /RS485)
3 - CAN port 1
4 - CAN port 2
5 - I2C port
6 - SPI port
7 - 10Mbit Ethernet
8 - RJ45 Ethernet
multibus
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Our test device
• It is an extended basic flex board;• We connected the dsPic33 core to:
• Set of buttons (input);• Set of leds (output);• LCD display (status display).
• We have in mind to simulate an elevator controller:• its implementation starts from FSM modeling;• the model is validated by OTS tools (Uppaal);• the code generation is done by hand.
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How to program our device
• Our FLEX board should run a specific program (firmware);
• We need a compiler to translate from C to machine code;
• We need a linker command file that allows the test code to be targeted to the dsPIC33;
• We need a tool to transfer the firmware from the PC to the MCU flash memory.
MPLAB_C30
gld script
Microchip ICD2
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Peripheral Mapping
• Expansion Board PIN I/O:• Leds -> PortD (output)• But’s -> PortG (input)• LCD -> PortA (output)
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MCU I/O
• A port is a set of analog/digital enabled pins.• A port can be configured to catch analog or digital
inputs. Digital signals can have a duration (like those generated by pushing buttons) or can be “levels” (latch mode).• of course finite signals must be caught while high.
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How to configure ports
• dsPic has 7 ports defined in the included header:
• #include "p33FJ256MC710.h"• Configuring a port for OUTPUT
void initLeds (void){
TRISDbits.TRISD0 = 0;TRISDbits.TRISD1 = 0;TRISDbits.TRISD2 = 0;TRISDbits.TRISD3 = 0;TRISDbits.TRISD4 = 0;TRISDbits.TRISD5 = 0;TRISDbits.TRISD6 = 0;TRISDbits.TRISD7 = 0;TRISDbits.TRISD8 = 0;TRISDbits.TRISD9 = 0;TRISDbits.TRISD10 = 0;TRISDbits.TRISD11 = 0;TRISDbits.TRISD12 = 0;TRISDbits.TRISD13 = 0;TRISDbits.TRISD14 = 0;TRISDbits.TRISD15 = 0;
}:
• Configuring a port for INPUT:
void initButtons (void){
TRISGbits.TRISG6 = 1; TRISGbits.TRISG7 = 1; TRISGbits.TRISG8 = 1; TRISGbits.TRISG9 = 1;
}
4 Buttons
16 pels of the LCD
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How to read/write ports
• Writing OUTPUT:
void setLed ( int led, int on_off ){
switch (led){case 0:LATDbits.LATD0 = on_off;break;case 1:LATDbits.LATD1 = on_off;break;case 2:LATDbits.LATD2 = on_off;break;case 3:LATDbits.LATD3 = on_off;break;}
}
• Reading INPUT:
int getButton ( int j ){switch (j){case 0: return !PORTGbits.RG6;case 1: return !PORTGbits.RG7;case 2: return !PORTGbits.RG8;case 3: return !PORTGbits.RG9;}
}
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HOWTO initialize and transit
static enum State {IDLE, S0, S1, S2, S3
};static enum Signal {
ABSENT, GO_TO_S0, GO_TO_S1, GO_TO_S2, GO_TO_S3
};
void FSMInit(FSM *me){me->state_ = IDLE;
}void FSMTran_(FSM *me, unsigned int
dest){
me->state_ = dest;}
enum Signal FSMGetSignals(FSM *me){if (b0)
return GO_TO_S0;else if (b1)
return GO_TO_S1;else if (b2)
return GO_TO_S2;else if (b3)
return GO_TO_S3;
return ABSENT;}
init
transition
signal generation
