fet440_adc12_03.s43

MSP430 code examples

;******************************************************************************
;   MSP-FET430P440 Demo - ADC12, Sample A10 Temp, Set P5.1 if temp ++ ~2c
;
;   Description: Use ADC12 and the integrated temperature sensor to detect
;   temperature gradients. The temperature sensor output voltage is sampled
;   every ~125ms and compared with the defined delta values using an ISR.
;   Sample time is 256 ADC12CLK cycles which needs to be greater than
;   30us for temperature sensor (see datasheet). ADC12 is operated in
;   repeat-single channel mode with the sample and convert trigger sourced
;   from Timer_A CCR1. The ADC12MEM0_IFG at the end of each converstion will
;   trigger an ISR.
;   ACLK = n/a, MCLK = SMCLK = default DCO, ADC12CLK = ADC12OSC
;
;                 MSP430F449
;             -----------------
;         /|\|              XIN|-
;          | |                 |
;          --|RST          XOUT|-
;            |                 |
;            |A10 (Temp)   P5.1|-->LED
;
;
;   M. Buccini
;   Texas Instruments Inc.
;   Feb 2005
;   Built with IAR Embedded Workbench Version: 3.21A
;******************************************************************************
#include  <msp430x44x.h>

ADCDeltaOn  EQU     12                      ;  ~ 2 Deg C delta for LED on
                                            ;
;------------------------------------------------------------------------------
            ORG     01100h                  ; Program Start
;------------------------------------------------------------------------------
RESET       mov.w   #0A00h,SP               ; Initialize stack pointer
            mov.w   #WDTPW+WDTHOLD,WDTCTL   ; Stop watchdog
            mov.w   #SHS_1+SHP+CONSEQ_2,&ADC12CTL1  ; TA trig., rpt conv
            mov.b   #SREF_1+INCH_10,&ADC12MCTL0  ; Channel A10, Vref+
            bis.w   #001h,&ADC12IE          ; Enable ADC12IFG.0
            mov.w   #SHT0_8+REF2_5V+REFON+ADC12ON+ENC,&ADC12CTL0  ; Config ADC12
            mov.w   #OUTMOD_4,&TACCTL1      ; Toggle on EQU1 (TAR = 0)
            mov.w   #TASSEL_2+MC_2,&TACTL   ; SMCLK, cont-mode
ADC_Wait    bit.w   #001h,&ADC12IFG         ; First conversion?
            jz      ADC_Wait
            mov.w   &ADC12MEM0,R4           ; Read out 1st ADC value
            add.w   #ADCDeltaOn,R4          ;
            clr.b   &P5OUT                  ; Clear P5
            bis.b   #02h,&P5DIR             ; P5.1 as output

                                            ;
Mainloop    bis.w   #LPM0+GIE,SR            ; Enter LPM0, enable interrupts
            nop                             ; Required only for debugger
                                            ;
;------------------------------------------------------------------------------
ADC12_ISR;
;------------------------------------------------------------------------------
            cmp.w   R4,&ADC12MEM0           ; ADC12MEM0 = A10 > R4
            jlo     ADC_ISR_1               ; Again
            bis.b   #02h,&P5OUT             ; P5.1 = 1
            reti                            ;		
ADC_ISR_1   bic.b   #02h,&P5OUT             ; P5.1 = 0
            reti                            ;		
                                            ;
;------------------------------------------------------------------------------
;           Interrupt Vectors
;------------------------------------------------------------------------------
            ORG     0FFFEh                  ; RESET Vector
            DW      RESET                   ;
            ORG     0FFEEh                  ; ADC12 Vector
            DW      ADC12_ISR               ;
            END