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/* --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--*/ //***************************************************************************** // MSP430x42x0 Demo - SD16_A, Using the Integrated Battery Sensor // // Description: This example shows how to use the SD16_A module's integrated // Battery sensor (connected to input channel 5) to measure VCC. // A single conversion is initiated and then the CPU is disabled by entering // LPM0. Once the conversion has completed, a SD16_A interrupt occurs and // stores the result in variable "ADCresult". LED lights if batter is low // ACLK = LFXT1 = 32768 Hz, MCLK = SMCLK = DCO = 32 x ACLK = 1048576 Hz // //* An external watch crystal on XIN XOUT is required for ACLK *// // //* Minimum Vcc is required for SD16_A module - see datasheet *// // //* 100nF cap btw Vref and AVss is recommended when using 1.2V ref *// // // MSP430F4270 // ----------------- // /|\| XIN|- // | | | 32kHz // --|RST XOUT|- // | | // |A5+ | ( A5+, A5- connected internally ) // |A5- | // | | // | VREF |---+ // | | | // | | -+- 100nF // | | -+- // | | | // | AVss |---+ // | | // // L. Westlund / S. Karthikeyan // Texas Instruments Inc. // June 2005 // Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.30A //***************************************************************************** #include <msp430.h>
#define LOW_BAT 0xBFFF // ~3V
static unsigned int ADCresult;
int main(void) { volatile unsigned int i; // Use volatile to prevent removal // by compiler optimization P1DIR |= 0x01;
WDTCTL = WDTPW + WDTHOLD; // Stop WDT FLL_CTL0 |= XCAP14PF; // Configure load caps for (i = 0; i < 10000; i++); // Delay for 32 kHz crystal to // stabilize
SD16CTL = SD16REFON+SD16SSEL0; // 1.2V ref, SMCLK SD16CCTL0 |= SD16SNGL+SD16IE ; // Single conv, enable interrupt SD16INCTL0 |= SD16INCH_5; // Select Channel A5 for (i = 0; i < 0x3600; i++); // Delay for 1.2V ref startup
__enable_interrupt(); // Enable general interrupts
while (1) { SD16CCTL0 |= SD16SC; // Set bit to start conversion __bis_SR_register(LPM0_bits); // Enter LPM0 if( ADCresult < LOW_BAT ) { P1OUT |= 0x01; } else { P1OUT &= ~0x01; } __no_operation(); //SET BREAKPOINT HERE } }
