内容: //***************************************************************************** // 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 //--|RSTXOUT|- //| | //|A5+| ( A5+, A5- connected internally ) //|A5-| //| | //|VREF |---+ //| | | //| |-+- 100nF //| |-+- //| | | //|AVss |---+ //| | // //L. Westlund / S. Karthikeyan //Texas Instruments Inc. //June 2005 //Built with IAR Embedded Workbench Version: 3.30A //***************************************************************************** ＃i nclude #define LOW_BAT 0xBFFF// ~3V static unsigned int ADCresult; void 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 _EINT();// Enable general interrupts while (1) { SD16CCTL0 |= SD16SC;// Set bit to start conversion _BIS_SR(LPM0_bits); // Enter LPM0 if( ADCresult < LOW_BAT ) { P1OUT |= 0x01; } else { P1OUT &= ~0x01; } _NOP(); //SET BREAKPOINT HERE } } #pragma vector=SD16_VECTOR __interrupt void SD16ISR(void) { switch (SD16IV) { case 2: // SD16MEM Overflow break; case 4: // SD16MEM0 IFG ADCresult = SD16MEM0; // Save results (clears IFG) break; } _BIC_SR_IRQ(LPM0_bits); // Exit LPM0 }
《匠人手记》推荐网上购书渠道： 
匠人学习：
