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Файл:Микропроцессорная техника / MSP430G2xx3_Code_Examples / msp430g2xx3_pinosc_01
.c/* --COPYRIGHT--,BSD_EX
* Copyright (c) 2012, Texas Instruments Incorporated
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Texas Instruments Incorporated nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*******************************************************************************
*
* MSP430 CODE EXAMPLE DISCLAIMER
*
* MSP430 code examples are self-contained low-level programs that typically
* demonstrate a single peripheral function or device feature in a highly
* concise manner. For this the code may rely on the device's power-on default
* register values and settings such as the clock configuration and care must
* be taken when combining code from several examples to avoid potential side
* effects. Also see www.ti.com/grace for a GUI- and www.ti.com/msp430ware
* for an API functional library-approach to peripheral configuration.
*
* --/COPYRIGHT--*/
//******************************************************************************
// MSP430G2xx3 Demo - Capacitive Touch, Pin Oscillator Method, 1 button
//
// Description: Basic 1-button input using the built-in pin oscillation feature
// on GPIO input structure. PinOsc signal feed into TA0CLK. WDT interval is used
// to gate the measurements. Difference in measurements indicate button touch.
// LEDs flash if input is touched.
//
// ACLK = VLO = 12kHz, MCLK = SMCLK = 1MHz DCO
//
// MSP430G2xx3
// -----------------
// /|\| XIN|-
// | | |
// --|RST XOUT|-
// | |
// | P1.1|<--Capacitive Touch Input 1
// | |
// LED 2 <--|P1.6 |
// | |
// LED 1 <--|P1.0 |
// | |
// | |
//
// Brandon Elliott/D. Dang
// Texas Instruments Inc.
// November 2010
// Built with IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430.h>
/* Define User Configuration values */
/*----------------------------------*/
/* Defines WDT SMCLK interval for sensor measurements*/
#define WDT_meas_setting (DIV_SMCLK_512)
/* Defines WDT ACLK interval for delay between measurement cycles*/
#define WDT_delay_setting (DIV_ACLK_512)
/* Sensor settings*/
#define KEY_LVL 220 // Defines threshold for a key press
/*Set to ~ half the max delta expected*/
/* Definitions for use with the WDT settings*/
#define DIV_ACLK_32768 (WDT_ADLY_1000) // ACLK/32768
#define DIV_ACLK_8192 (WDT_ADLY_250) // ACLK/8192
#define DIV_ACLK_512 (WDT_ADLY_16) // ACLK/512
#define DIV_ACLK_64 (WDT_ADLY_1_9) // ACLK/64
#define DIV_SMCLK_32768 (WDT_MDLY_32) // SMCLK/32768
#define DIV_SMCLK_8192 (WDT_MDLY_8) // SMCLK/8192
#define DIV_SMCLK_512 (WDT_MDLY_0_5) // SMCLK/512
#define DIV_SMCLK_64 (WDT_MDLY_0_064) // SMCLK/64
#define LED_1 (0x01) // P1.0 LED output
#define LED_2 (0x40) // P1.6 LED output
// Global variables for sensing
unsigned int base_cnt, meas_cnt;
int delta_cnt;
char key_pressed;
int cycles;
/* System Routines*/
void measure_count(void); // Measures each capacitive sensor
void pulse_LED(void); // LED gradient routine
/* Main Function*/
int main(void)
{
unsigned int i,j;
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
if (CALBC1_1MHZ==0xFF) // If calibration constant erased
{
while(1); // do not load, trap CPU!!
}
DCOCTL = 0; // Select lowest DCOx and MODx settings
BCSCTL1 = CALBC1_1MHZ; // Set DCO to 1MHz
DCOCTL = CALDCO_1MHZ;
BCSCTL3 |= LFXT1S_2; // LFXT1 = VLO
IE1 |= WDTIE; // enable WDT interrupt
P2SEL = 0x00; // No XTAL
P1DIR = LED_1 + LED_2; // P1.0 & P1.6 = LEDs
P1OUT = 0x00;
__bis_SR_register(GIE); // Enable interrupts
measure_count(); // Establish baseline capacitance
base_cnt = meas_cnt;
for(i=15; i>0; i--) // Repeat and avg base measurement
{
measure_count();
base_cnt = (meas_cnt+base_cnt)/2;
}
/* Main loop starts here*/
while (1)
{
j = KEY_LVL;
key_pressed = 0; // Assume no keys are pressed
measure_count(); // Measure all sensors
delta_cnt = base_cnt - meas_cnt; // Calculate delta: c_change
/* Handle baseline measurment for a base C decrease*/
if (delta_cnt < 0) // If negative: result increased
{ // beyond baseline, i.e. cap dec
base_cnt = (base_cnt+meas_cnt) >> 1; // Re-average quickly
delta_cnt = 0; // Zero out for pos determination
}
if (delta_cnt > j) // Determine if each key is pressed
{ // per a preset threshold
j = delta_cnt;
key_pressed = 1; // key pressed
}
else
key_pressed = 1;
/* Delay to next sample, sample more slowly if no keys are pressed*/
if (key_pressed)
{
BCSCTL1 = (BCSCTL1 & 0x0CF) + DIVA_0; // ACLK/(0:1,1:2,2:4,3:8)
cycles = 20;
}
else
{
cycles--;
if (cycles > 0)
BCSCTL1 = (BCSCTL1 & 0x0CF) + DIVA_0; // ACLK/(0:1,1:2,2:4,3:8)
else
{
BCSCTL1 = (BCSCTL1 & 0x0CF) + DIVA_3; // ACLK/(0:1,1:2,2:4,3:8)
cycles = 0;
}
}
WDTCTL = WDT_delay_setting; // WDT, ACLK, interval timer
/* Handle baseline measurment for a base C increase*/
if (!key_pressed) // Only adjust baseline down
{ // if no keys are touched
base_cnt = base_cnt - 1; // Adjust baseline down, should be
} // slow to accomodate for genuine
pulse_LED(); // changes in sensor C
__bis_SR_register(LPM3_bits);
}
} // End Main
/* Measure count result (capacitance) of each sensor*/
/* Routine setup for four sensors, not dependent on NUM_SEN value!*/
void measure_count(void)
{
TA0CTL = TASSEL_3+MC_2; // TACLK, cont mode
TA0CCTL1 = CM_3+CCIS_2+CAP; // Pos&Neg,GND,Cap
/*Configure Ports for relaxation oscillator*/
/*The P2SEL2 register allows Timer_A to receive it's clock from a GPIO*/
/*See the Application Information section of the device datasheet for info*/
P1DIR &= ~ BIT1; // P1.1 is the input used here
P1SEL &= ~ BIT1;
P1SEL2 |= BIT1;
/*Setup Gate Timer*/
WDTCTL = WDT_meas_setting; // WDT, ACLK, interval timer
TA0CTL |= TACLR; // Clear Timer_A TAR
__bis_SR_register(LPM0_bits+GIE); // Wait for WDT interrupt
TA0CCTL1 ^= CCIS0; // Create SW capture of CCR1
meas_cnt = TACCR1; // Save result
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
P1SEL2 &= ~BIT1;
}
void pulse_LED(void)
{
if(key_pressed)
{
P1OUT ^= LED_1 + LED_2;
}else{
P1OUT = 0;
}
}
/* Watchdog Timer interrupt service routine*/
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
{
TA0CCTL1 ^= CCIS0; // Create SW capture of CCR1
__bic_SR_register_on_exit(LPM3_bits); // Exit LPM3 on reti
}
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