Hi, I am building a mini robot using the msp430 launchpad. The robot has an IR proximity sensor in front and it stops and backs up when it senses an object too close. Every thing was working fine until I thought it would be cool to put the sensor on a mini servo so it can sweep the area and see more objects. So now I am using timerA0 for the drive motors, timerA1 for the servo and the ADC for the sensor. The problem I am having is it seems timerA1 may somehow be interfering with the ADC. Both the servo and the drive motors work together until the sensor sees an object, then it never escapes the 'backup'code, and I don't even think the ADC interrupt is getting fired anymore. I think this results in some misunderstandings I have about the timers, such as whats the difference between TIMER1_A1_VECTOR and TIMER1_A0_VECTOR? Likewise for timerA0. I haven't been able to find documentation about it. Any help or tips on how to improve my code are much appreciated. Thanks! #include #define AIN1 BIT4 //Input 1 for motor A, PORT 1 #define AIN2 BIT5 //Input 2 for motor A, PORT 1 #define BIN1 BIT4 //Input 1 for motor B, PORT 2 #define BIN2 BIT5 //Input 2 for motor B, PORT 2 #define stdby BIT2 //Stand by to release motor, PORT 2 #define MCU_CLOCK 1100000UL #define PWM_FREQUENCY 50 // In Hertz, ideally 50Hz. int pos = 0; int timer = 0; void GPIO_Setup() { /*** GPIO Set-Up ***/ P1DIR |= AIN1 | AIN2; //Inputs for direction/mode control P1DIR |= BIT2 | BIT7; P1SEL |= BIT2; //PWM for motor A P2DIR |= stdby | BIN1 | BIN2; //Release motor by pulling high P2DIR |= BIT1; // P2.1 = output P2SEL |= BIT1; // P2.1 = TA1 output } void Timer0A_Setup() { /*** Timer0_A Set-Up ***/ TA0CTL |= TASSEL_2 | MC_1 | ID_3; TA0CCR0 |= 1000; TA0CCTL1 |= OUTMOD_7; TA0CCR1 |= 500; } void Timer1A_Setup() { unsigned int PWM_Period = (MCU_CLOCK / PWM_FREQUENCY); // PWM Period unsigned int PWM_Duty = 1000; TA1CCTL1 = OUTMOD_7 + CCIE; // TACCR1 reset/set TA1CTL = TASSEL_2 + MC_1; // SMCLK, upmode TA1CCR0 = PWM_Period-1; // PWM Period TA1CCR1 = PWM_Duty; // TACCR1 PWM Duty Cycle } void ADC_Setup() { ADC10CTL0 = SREF_1 + REFON + REF2_5V + ADC10SHT_2 + ADC10ON + ADC10IE; // ADC10ON, interrupt enabled __enable_interrupt(); // Enable interrupts. TACCR0 = 300; // Delay to allow Ref to settle ADC10CTL1 = INCH_0; // input P1.0 A0 ADC10AE0 |= BIT0; // PA.0 ADC option select } void forward() { //This just makes the motor go straight from the start TA0CCR1 = 500; //Set motor conditions CCW Motor A P1OUT &= ~AIN1; //AIN1 LOW P1OUT |= AIN2; //AIN2 HIGH //Set motor conditions CCW Motor B P2OUT &= ~BIN1; //AIN1 LOW P2OUT |= BIN2; //AIN2 HIGH //TA1CTL = TASSEL_2 + MC_1; //For some reason this makes the ADC freak out. It stops sampling it appears } void backUp() { //TA1CTL = TASSEL_2 + MC_0; // SMCLK, stop the timer //TA1CCR1 = 500; TA0CCR1 = 500; //Set motor conditions CW Motor A P2OUT = 0; P2OUT |= stdby; //stdby low (OFF) P1OUT = 0; P1OUT &= ~AIN2; //AIN1 LOW P1OUT |= AIN1; //AIN2 HIGH P2OUT |= stdby; //stdby low (ON) while(ADC10MEM > 415) { P1OUT |= BIT7; ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start __bis_SR_register(CPUOFF + GIE); // LPM0, ADC10_ISR will force exit if(ADC10MEM 415) //This is a measure of how close an object is (its too close now, back up) { // P2OUT &= ~stdby; //stdby low (OFF) P1OUT |= BIT7; shortBrake(); backUp(); } else { //shortBrake(); P2OUT |= stdby; //stdby low (ON) forward(); P1OUT &= ~BIT7; } } } // ADC10 interrupt service routine #pragma vector=ADC10_VECTOR __interrupt void ADC10_ISR(void) { __bic_SR_register_on_exit(CPUOFF); // Clear CPUOFF bit from 0(SR) } #pragma vector=TIMER1_A1_VECTOR // Timer1 A1 interrupt service routine __interrupt void Timer1_A1 (void) { timer++; if(pos == 0 && timer == 50) { TA1CCR1 = 500; pos = !pos; timer = 0; } else if(pos == 1 && timer == 50) { TA1CCR1 = 4000; pos = !pos; timer = 0; } TA1CCTL1 &= ~CCIFG; }
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