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hello,
can I do multitasking in ARM LPC2148. I want to display on LCD, LED and 7segment at the same time.
is it possible?????
do I need to install some operating system like real time Linux???
I am working with LPC2148. In this project, I am displaying data on LCDs which is continuously changing. also I want to read input ports.
can it be done like operating system working??? one program for checking i/p ports and second to display data on LCDs. only one is executing for fixed time and after timeout storing its status on stack and second is executing for fixed time..
Search keil forum for "RTX". Also inspect your "Options for target...", Target page ("operating system").
As Andy has already mentioned, multitasking is not necessary for what you've described.
A simple supervisory loop processing each module would almost certainly be sufficient.
I wrote this at 2008.Nov.04 =>
int main (void) { char LFnCR[] = "\n\r"; init_VIC(); UARTInit(9600); /* baud rate setting */ init_timer(); enable_timer(0); PINSEL2 = PINSEL2 & (~0x08); // for GPIO 8LED IODIR1 = LED8SET; // for GPIO 8LED MSPI_init(); while (1) { /* Loop forever */ GPIO8LED_show(); MSPI7LED_show(); UART0rbREAD(); if (cmd_ready) { UART0sbWRITE( (BYTE *)cmd_string, strlen((const char *)cmd_string) ); UART0sbWRITE( (BYTE *)LFnCR , 2 ); UART0sendKICK(); memset( cmd_string, 0x00, 32 ); cmdstr_i = 0; cmd_ready = 0; } KEYS_control(); } // return 0; } void KEYS_check(void) { IOPIN0_last = IOPIN0_this; IOPIN0_this = IOPIN0; IOPIN0_stat = IOPIN0_last ^ IOPIN0_this & IOPIN0_last; if ( ( IOPIN0_stat & KEY1 ) == KEY1 ) KEY1_pressed = 1; if ( ( IOPIN0_stat & KEY2 ) == KEY2 ) KEY2_pressed = 1; if ( ( IOPIN0_stat & KEY3 ) == KEY3 ) KEY3_pressed = 1; if ( ( IOPIN0_stat & KEY4 ) == KEY4 ) KEY4_pressed = 1; if ( ( IOPIN0_stat & KEY5 ) == KEY5 ) KEY5_pressed = 1; if ( ( IOPIN0_stat & KEY6 ) == KEY6 ) KEY6_pressed = 1; timer_KEYpress = 2; } void KEYS_control(void) { static BYTE GPIO8LED_pos = 1; static BYTE MSPI7LED_pos = 0; BYTE const HEX_TAB[16] = { // 0 1 2 3 4 5 6 7 8 9 0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90, // A b C d E F 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E }; if ( KEY1_pressed == 1 ) { GPIO8LED_show_on = 1 - GPIO8LED_show_on; KEY1_pressed = 0; } if ( KEY4_pressed == 1 ) { MSPI7LED_show_on = 1 - MSPI7LED_show_on; KEY4_pressed = 0; } if ( GPIO8LED_show_on == 0 ) { if ( KEY2_pressed == 1 ) { if ( GPIO8LED_pos > 1 ) GPIO8LED_pos--; KEY2_pressed = 0; } if ( KEY3_pressed == 1 ) { if ( GPIO8LED_pos < 8 ) GPIO8LED_pos++; KEY3_pressed = 0; } IOCLR1 = 1 << (17+GPIO8LED_pos) ; IOSET1 = ~( 1 << (17+GPIO8LED_pos) ); } if ( MSPI7LED_show_on == 0 ) { if ( KEY5_pressed == 1 ) { if ( MSPI7LED_pos > 0 ) MSPI7LED_pos--; KEY5_pressed = 0; } if ( KEY6_pressed == 1 ) { if ( MSPI7LED_pos < 15 ) MSPI7LED_pos++; KEY6_pressed = 0; } IOCLR0 = HC595_CS; SPI_SPDR = HEX_TAB[MSPI7LED_pos]; while( 0 == (SPI_SPSR & 0x80) ); IOSET0 = HC595_CS; } }
void GPIO8LED_show(void) { static BYTE GPIO8LED_on = 1; static BYTE GPIO8LED_i = 0; if ( ( timer_GPIO8LED == 0 ) && ( GPIO8LED_show_on ) ) { if (GPIO8LED_on) { IOSET1 = ~( LED8SET & ( 7 << (18+GPIO8LED_i) ) ); } else { IOCLR1 = LED8SET & ( 7 << (18+GPIO8LED_i) ); if ( GPIO8LED_i == 7 ) { GPIO8LED_i = 0; } else { GPIO8LED_i++; } } GPIO8LED_on = 1 - GPIO8LED_on; timer_GPIO8LED = 8; } } void MSPI_init(void) { //PINSEL0 = (PINSEL0 & 0xFFFF00FF) | 0x00005500; // Connect SPI PINSEL0 = (PINSEL0 & (~(0xFF << 8))) | (0x55 << 8) ; IODIR0 = HC595_CS; S0SPCCR = 0x52; // Set SPI Clock S0SPCR = (0 << 3) | // CPHA = 0, [del] (1 << 4) | // CPOL = 1, SCK [del] (1 << 5) | // MSTR = 1, SPI [del] (0 << 6) | // LSBF = 0, SPI [del] (0 << 7); // SPIE = 0, [del] } void MSPI7LED_show(void) { static BYTE MSPI7LED_i = 0; BYTE const HEX_TAB[16] = { // 0 1 2 3 4 5 6 7 8 9 0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90, // A b C d E F 0x88, 0x83, 0xC6, 0xA1, 0x86, 0x8E }; if ( ( timer_MSPI7LED == 0 ) && ( MSPI7LED_show_on ) ) { IOCLR0 = HC595_CS; // 74HC595 SPI_SPDR = HEX_TAB[MSPI7LED_i]; while( 0 == (SPI_SPSR & 0x80) ); // Wait IOSET0 = HC595_CS; if ( MSPI7LED_i == 15 ) { MSPI7LED_i = 0; } else { MSPI7LED_i++; } timer_MSPI7LED = 95; } }
void Timer0Handler (void) __irq { timer_counter++; if ( timer_KEYpress != 0 ) timer_KEYpress--; else KEYS_check(); if ( timer_GPIO8LED != 0 ) timer_GPIO8LED--; if ( timer_MSPI7LED != 0 ) timer_MSPI7LED--; T0IR = 1; /* clear interrupt flag */ VICVectAddr = 0; /* Acknowledge Interrupt */ }
The above code which I posted, is a [low quality] demonstration for: A simple supervisory loop processing each module would almost certainly be sufficient.