// MSP430G2x13/G2x53 Demo - Comp_A,
//Simple 2.2V Low Battery Detect
// Description: Two comparator_A reference generators 0.25*Vcc and ~0.55V
// are compared for a simple battery check of 2.2V. In the subroutine
// Batt_Check, a small capacitor between P2.3 and Vss is first charged
// to 0.25*Vcc and then compared to ~0.55V. If 0.25*Vcc,
// is above ~0.55V, P1.0 is toggled, else set. Batt_Check is called
// constantly in an endless loop - in an actual application, Batt_Check
// should be called infrequently to save power.
// ACLK = n/a, MCLK = SMCLK = default DCO
//
// There is a tolerance of the Comp_A reference generator and in the
// device specific datasheet. In most applications, the tolerence of the
// reference generator is more than adequate to detect Low Battery.
//
// MSP430G2x13/G2x53
// -----------------
// /|\ | XIN|-
// | | |
// ---|RST XOUT|-
// | |e
// +-----|P1.1/CA1 P1.0|-->LED
// | | |
// ===.1uf| |
// | | |
// +-----|Vss
//
void Batt_Check(void);
unsigned int i;
//
// D. Dang
// Texas Instruments Inc.
// December 2010
// Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430g2553.h>
void main (void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1DIR |= 0x01; // P1.0 output
CACTL2 = P2CA4; // P1.1 = CA1
while (1) // Mainloop
{
Batt_Check();
}
}
void Batt_Check(void) {
CACTL1 = CAREF_1 + CAON; // 0.25*Vcc on P1.1, Comp. on
i = 30000; // delay
while(i>0) {
i--;
}
CACTL1 = CARSEL + CAREF_2 + CAREF_1 + CAON; // CAREF=3:0.55V on -, Comp. on
if (CACTL2 & CAOUT)
P1OUT ^= 0x01; // P1.0 toggle
else P1OUT |= 0x01; // P1.0 set
CACTL1 = 0x00; // Disable Comp_A, save power
}
这程序注释说明里面写的是P2.3与Vss有电容而图里面写的却是P1.1，而且到底应该怎么去验证这个程序？还有我不太懂"toggle"是什么意思，请专家指教。
