Hi all. The question is about Launchpad use for low-power applications.
Being in process of developing my program, I decided to measure power consumption. And it was about 27mA. Pretty high, yes.
As it noticed in SLAU533C, i switched off FET connectors, but the consumption decreased maximum to 3 mA.
Then I flashed the crystal with provided by TI code example (see below) to enter LPM3, disconnected all cables except of 3v battery connectors.
But generally nothing changed, and multimeter still shows about 22mA.
I tested the multimeter loading only resistor, it works good.
#include <msp430.h>
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
// Enable XT1
P5SEL |= BIT4+BIT5; // Port select XT1
UCSCTL6 &= ~(XT1OFF); // XT1 On
UCSCTL6 |= XCAP_3; // Internal load cap
// Loop until XT1 & DCO stabilizes
do
{
UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);
// Clear XT2,XT1,DCO fault flags
SFRIFG1 &= ~OFIFG; // Clear fault flags
}while (SFRIFG1&OFIFG); // Test oscillator fault flag
UCSCTL6 &= ~(XT1DRIVE_3); // Xtal is now stable, reduce drive
// strength
// Port Configuration
P1OUT = 0x00;P2OUT = 0x00;P3OUT = 0x00;P4OUT = 0x00;P5OUT = 0x00;P6OUT = 0x00;
P7OUT = 0x00;P8OUT = 0x00;PJOUT = 0x00;
P1DIR = 0xFF;P2DIR = 0xFF;P3DIR = 0xFF;P4DIR = 0xFF;P5DIR = 0xFF;P6DIR = 0xFF;
P7DIR = 0xFF;P8DIR = 0xFF;PJDIR = 0xFF;
// Disable VUSB LDO and SLDO
USBKEYPID = 0x9628; // set USB KEYandPID to 0x9628
// access to USB config registers enabled
USBPWRCTL &= ~(SLDOEN+VUSBEN); // Disable the VUSB LDO and the SLDO
USBKEYPID = 0x9600; // access to USB config registers disabled
// Disable SVS
PMMCTL0_H = PMMPW_H; // PMM Password
SVSMHCTL &= ~(SVMHE+SVSHE); // Disable High side SVS
SVSMLCTL &= ~(SVMLE+SVSLE); // Disable Low side SVS
__bis_SR_register(LPM3_bits); // Enter LPM3
__no_operation(); // For debugger
}
After a was looking around there, and the only which I found was about connections the VCORE pin to 470n capacitor. But as I can notice, in Launchpad it is already connected. I used only 3.3v, 5v and GND male headers.
Can someone helps me and give the right direction.
Thanks a lot.
