#include "msp430.h" #include #include #include volatile int a=0; volatile int b=0; volatile int c=0; volatile unsigned char TXData; volatile unsigned char TXByteCtr; volatile unsigned char RXByteCtr; //volatile unsigned char RXByteCtrHmd; volatile uint16_t ReceivedData; float fTemp; float fHumid; void main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop WDT P3DIR |= BIT6 +BIT7; P3OUT &= ~(BIT6 +BIT7); /* PMAPPWD = 0x02D52; // Get write-access to port mapping regs P1MAP3 = PM_UCB0SDA; // Map UCB0SDA output to P2.6 P1MAP1 = PM_UCB0SCL; // Map UCB0SCL output to P2.7 PMAPPWD = 0; // Lock port mapping registers */ P1SEL |= BIT3 + BIT2; // Select P2.6 & P2.7 to I2C function UCB0CTL1 |= UCSWRST; // Enable SW reset UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset UCB0BR0 = 16; // fSCL = SMCLK/12 = ~100kHz UCB0BR1 = 0; //0x80 is the address of sht21 //UCB0I2CSA = 0x48; // Slave Address is 048h UCB0I2CSA = 0x40; // Slave Address is 040h UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation UCB0IE |= UCTXIE; UCB0IE |= UCRXIE;// Enable TX interrupt UCB0IE |= UCNACKIE; UCB0IE |= UCSTPIE ; UCB0IE |= UCSTTIE ; /* TXDataTemp = 0xE3; TXDataHumidity=0xE5;// Holds TX data*/ while (1) { __delay_cycles(15000); TXByteCtr = 0x01; // Load TX byte counter RXByteCtr = 0x01; //RXByteCtrHmd=0x01; // while (UCB0CTL1 & UCTXSTP); if (UCB0STAT & UCBBUSY) // test if bus to be free { // otherwise a manual Clock on is // generated P1SEL &= ~BIT2; // Select Port function for SCL P1OUT &= ~BIT2; // P1DIR |= BIT2; // drive SCL low P1SEL |= BIT3 +BIT2; }// Ensure stop condition got sent TXData= 0xE3; UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition //__delay_cycles(); __bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/ interrupts /*loop:// is TX'd if(a==1) { a=0; printf("%s","for transmission problem"); UCB0CTL1 |= UCTR +UCTXSTT; // I2C stop condition //__delay_cycles(50); __bis_SR_register(LPM0_bits + GIE); if (c!=1) goto loop; }*/ /*if(b==1){ b=0;*/ /*while (UCB0CTL1 & UCTXSTP); while (UCB0STAT&UCBBUSY) ;*/ UCB0CTL1 &=~UCTR;// Use SMCLK, keep SW reset // Clear SW reset, resume operation // Enable TX interrupt UCB0CTL1 |= UCTXSTT; __bis_SR_register(LPM0_bits + GIE); fTemp = -46.85 + ((175.72)*((float) ReceivedData/65536)); printf("Temp=%f", fTemp ); /*}*/ /*loop2:// is TX'd if(a==1) { a=0; printf("%s","for receiving problem"); UCB0CTL1 &=~UCTR; UCB0CTL1 |= UCTXSTT; // I2C stop condition //__delay_cycles(50); __bis_SR_register(LPM0_bits + GIE); if (UCB0STAT&UCBBUSY) goto loop2; }*/ TXByteCtr = 0x01; // Load TX byte counter RXByteCtr = 0x01; TXData = 0xE5; UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition //__delay_cycles(); __bis_SR_register(LPM0_bits + GIE); UCB0CTL1 &=~UCTR;// Use SMCLK, keep SW reset // Clear SW reset, resume operation // Enable TX interrupt UCB0CTL1 |= UCTXSTT; __bis_SR_register(LPM0_bits + GIE); fHumid = -6 + ((125)*((float) ReceivedData/65536)); printf("Humidity=%f", fHumid ); printf("counter1=%d,counter2=%d\n",10,9); // Increment data byte } } //------------------------------------------------------------------------------ // The USCIAB0_ISR is structured such that it can be used to transmit any // number of bytes by pre-loading TXByteCtr with the byte count. //------------------------------------------------------------------------------ #pragma vector = USCI_B0_VECTOR __interrupt void USCI_B0_ISR(void) { switch(__even_in_range(UCB0IV,12)) { case 0: break; // Vector 0: No interrupts case 2: break; // Vector 2: ALIFG case 4: P3OUT |=BIT7; // UCB0CTL1 |= UCTXSTP; // I2C stop condition a=1; //P3OUT=BIT6; printf("%s","not acknowledgement interrupt"); __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0 break; // Vector 4: NACKIFG case 6: P3OUT |=BIT6; printf("%s","in start flag"); __bic_SR_register_on_exit(LPM0_bits); break; // Vector 6: STTIFG case 8: printf("%s","in stop flag"); __bic_SR_register_on_exit(LPM0_bits); break; // Vector 8: STPIFG case 10: if (RXByteCtr) { RXByteCtr--; ReceivedData= UCB0RXBUF<<8 ; UCB0CTL1 |= UCTXSTP; } else{ UCB0CTL1 |= UCTXNACK ; ReceivedData|= UCB0RXBUF; ReceivedData =ReceivedData>>2; ReceivedData=ReceivedData<<2; // tc = -46.85 + ((175.72)*((float) Temp/65536)); while(UCB0CTL1 & UCTXSTP); P3OUT |=BIT6; //printf("Temp=%f", tc ); __bic_SR_register_on_exit(LPM0_bits); } break; // Vector 10: RXIFG case 12: // Vector 12: TXIFG if (TXByteCtr) // Check TX byte counter { UCB0TXBUF = TXData; //(UCB0CTL1 & UCTXSTT);// Load TX buffer TXByteCtr--; // Decrement TX byte counter } else { //P3OUT ^= BIT6; // Toggle LED1 UCB0CTL1 |= UCTXSTP; while (UCB0CTL1 & UCTXSTP);// I2C stop condition // c=1 ; // Clear USCI_B0 TX int flag // b=1; printf("%s","transmission finished"); __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0 } break; default: break; } // __delay_cycles(500); } /* #include "msp430.h" #include #include #include volatile int a=0; volatile int b=0; volatile unsigned char TXData; volatile unsigned char TXByteCtr; volatile unsigned char RXByteCtr; volatile uint16_t Temp; void main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop WDT // __delay_cycles(2000000); P3DIR |= BIT6 +BIT7; P3OUT &= ~(BIT6 +BIT7); PMAPPWD = 0x02D52; // Get write-access to port mapping regs P1MAP3 = PM_UCB0SDA; // Map UCB0SDA output to P2.6 P1MAP1 = PM_UCB0SCL; // Map UCB0SCL output to P2.7 PMAPPWD = 0; // Lock port mapping registers P1SEL |= BIT1 + BIT3; // Select P2.6 & P2.7 to I2C function UCB0CTL1 |= UCSWRST; // Enable SW reset UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz UCB0BR1 = 0; //0x80 is the address of sht21 //UCB0I2CSA = 0x48; // Slave Address is 048h UCB0I2CSA = 0x40; // Slave Address is 040h UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation UCB0IE |= UCTXIE; // Enable TX interrupt UCB0IE |= UCNACKIE; TXData = 0xF3; // Holds TX data while (1) { TXByteCtr = 0x01; // Load TX byte counter RXByteCtr = 0x01; while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition //__delay_cycles(); __bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/ interrupts __no_operation(); // Remain in LPM0 until all data loop:// is TX'd if(a==1) { a=0; UCB0CTL1 |= UCTXSTT; // I2C stop condition //__delay_cycles(50); printf("%s","not acknowledgement interrupt outer"); __bis_SR_register(LPM0_bits + GIE); if (UCB0STAT&UCBBUSY) goto loop; } printf("counter1=%d,counter2=%d\n",10,9); // Increment data byte } } //------------------------------------------------------------------------------ // The USCIAB0_ISR is structured such that it can be used to transmit any // number of bytes by pre-loading TXByteCtr with the byte count. //------------------------------------------------------------------------------ #pragma vector = USCI_B0_VECTOR __interrupt void USCI_B0_ISR(void) { switch(__even_in_range(UCB0IV,12)) { case 0: break; // Vector 0: No interrupts case 2: break; // Vector 2: ALIFG case 4: // UCB0CTL1 |= UCTXSTP; // I2C stop condition a=1; printf("%s","not acknowledgement interrupt"); __bic_SR_register_on_exit(LPM0_bits); // Exit LPM0 break; // Vector 4: NACKIFG case 6: printf("%s","in start flag"); P3OUT=BIT6;break; // Vector 6: STTIFG case 8: printf("%s","in stop flag");P3OUT=BIT7;break; // Vector 8: STPIFG case 10: if (RXByteCtr) { RXByteCtr--; Temp= UCB0RXBUF<<8; UCB0CTL1 |= UCTXSTP; } else{ Temp|= UCB0RXBUF; while(UCB0CTL1 & UCTXSTP); P3OUT |=BIT6; __bic_SR_register_on_exit(LPM0_bits); }break; // Vector 10: RXIFG case 12: // Vector 12: TXIFG if (TXByteCtr) // Check TX byte counter { UCB0TXBUF = TXData; // Load TX buffer TXByteCtr--; // Decrement TX byte counter } else { //P3OUT ^= BIT6; // Toggle LED1 UCB0CTL1 |= UCTXSTP; while (UCB0CTL1 & UCTXSTP);// I2C stop condition // Clear USCI_B0 TX int flag __bic_SR_register_on_exit(LPM0_bits); b=1; printf("%s","transmission finished");// Exit LPM0 } break; default: break; } } */