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Hi all I'm sitting with the MCB2100 from Keil trying to get the capture input CAP1,0 & CAP1,1 to work (P0.10 and P0.11) I have used the following code to make the inputs capture friendly... PINSEL0&=0xFFAFFFFF; T1CCR=0x1B; // I would like to capture both falling and rising edge on both pins... As you can see from the T1CCR i have set it for no interrupt (i would like to do this but i cant figure out how to do interrupts in keil) Im running with a 12MHz crystal and the frequency on both inputs which i wish to capture is 250Hz (i would like to get the dutycycle variation) Can any one help me setting up the registers im kinda lost or give me some hints... Best regards Lasse Madsen |
LPC2129 - Capture help requested :)
Started by ●February 23, 2005
Reply by ●February 23, 20052005-02-23
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Maybe my working code fragments will help you. I have CAP1.0 and CAP1.1
connected together, one for capture rising edge, another for falling edge. So I can measure pulse duration with a 1/60 us resolution. // Function of Pins P0.0 - P0.1 //PINSEL0 #define F00 (1 << 0*2) /* TXD0 */ #define F01 (1 << 1*2) /* RXD0 */ #define F04 (1 << 4*2) /* SCK */ #define F05 (1 << 5*2) /* MISO */ #define F06 (1 << 6*2) /* MOSI */ #define F07 (1 << 7*2) /* SS0 necessary even for Master */ #define F08 (1 << 8*2) /* TXD1 */ #define F09 (1 << 9*2) /* RXD1 */ #define F10 (2 << 10*2) /* CAPTURE1.0 */ #define F11 (2 << 11*2) /* CAPTURE1.1 */ #define PINSEL0init (F00 | F01 | F04 | F05 | F06 | F07 | F08 | F09 | F10 | F11) ..... void InitController() { PINSEL0 = PINSEL0init; PINSEL1 = PINSEL1init; PINSEL2 &= 0xFFFFFFF0; IODIR0 = OUTPUTS0; IODIR1 = 0xFF0000; T1PR = T1Prescaler - 1; T1CCR = 0xA; // CAP1.1 - rising, CAP1.0 falling T1TCR = 0x1; // Enable Timer 1 IOCLR1 = 0xFF0000; } ...... // The sequence should always be: falling, rising falling = T1CR0; rising = T1CR1; while (1) { if ((T1CR1 != rising) && (T1CR0 != falling)) { falling = T1CR0; rising = T1CR1; duration = falling - rising; ..... } The same free running timer1 can be used for a lot of other tasks too. Best regards, Varuzhan ----- Original Message ----- From: Lasse Madsen To: Sent: Wednesday, February 23, 2005 8:26 PM Subject: [lpc2000] LPC2129 - Capture help requested :) Hi all I'm sitting with the MCB2100 from Keil trying to get the capture input CAP1,0 & CAP1,1 to work (P0.10 and P0.11) I have used the following code to make the inputs capture friendly... PINSEL0&=0xFFAFFFFF; T1CCR=0x1B; // I would like to capture both falling and rising edge on both pins... As you can see from the T1CCR i have set it for no interrupt (i would like to do this but i cant figure out how to do interrupts in keil) Im running with a 12MHz crystal and the frequency on both inputs which i wish to capture is 250Hz (i would like to get the dutycycle variation) Can any one help me setting up the registers im kinda lost or give me some hints... Best regards Lasse Madsen ------ Yahoo! Groups Links a.. To |
