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26/11/2012 #1


Timer 3 dspic30F Resetea
Buenas,

Me estoy peleando con el ADC del dspic30F6013A. Quiero configurar el ADC con el timer3, pero cuando activo el T3, T3CONbits.TON=1, el dsp se resetea.


Alguien podría explicarme qué está mal?

muchas gracias

Mi código es el siguiente:

Código:
void ADCInit (){

        //ADCON1 Register
        //Set up A/D for Automatic Sampling
        //Use Timer3 to provide sampling time
        //Set up A/D conversrion results to be read in 1.15 fractional
        //number format.
        //All other bits to their default state
        ADCON1bits.FORM = 3;
        ADCON1bits.SSRC = 2;
        ADCON1bits.ASAM = 1;


        //ADCON2 Register
        //Set up A/D for interrupting after 16 samples get filled in the buffer
        //All other bits to their default state
        ADCON2bits.SMPI = 15;
        //ADCON3 Register
        //We would like to set up a sampling rate of 8KHz
        //Total Conversion Time= 1/Sampling Rate = 125 microseconds
        //At 20 MIPS, Tcy = 50 ns = Instruction Cycle Time
        //Tad > 667ns (for -40C to 125C temperature range)
        //We will set up Sampling Time using Timer3 & Tad using ADCS<5:0> bits
        //All other bits to their default state
        //Let's set up ADCS arbitrarily to the maximum possible amount = 63
        //So Tad = Tcy*(ADCS+1)/2 = 1.6 microseconds
        //So, the A/D converter will take 14*Tad periods to convert each sample (12-bits ADC) =  14*1.6usec= 22.4usec. 
        ADCON3bits.ADCS = 63;

        //Next, we will to set up Timer 3 to time-out every 125 microseconds
        //As a result, the module will stop sampling and trigger a conversion
        //on every Timer3 time-out, i.e., 125 microseconds. At that time,
        //the conversion process starts and completes 14*Tad periods later.
        //When the conversion completes, the module starts sampling again
        //However, since Timer3 is already on and counting, about 103 (102.6usec)
        //microseconds later (=125 microseconds - 14*Tad), Timer3 will expire
        //again. Effectively, the module samples for 103 microseconds and
        //converts for 15 microseconds
        //NOTE: The actual sampling rate realized may be 7998.698 Hz (103 + 14*1.6 = 7974.48Hz)
        //      due to a small round off error. Ensure you provide the
        //      true sampling rate to dsPICworks if you are trying to plot
        //      the sampled or filtered signal.

        TMR3 = 0x0000;
        PR3 = SAMPCOUNT; // (FCY/SAMPLINGRATE)+1 = ((FOSC*PLL/4)/SAMPLINGRATE)+1 = ((10000000*8/4)/8000)+1 = 2501
        IFS0bits.T3IF = 0;
        IEC0bits.T3IE = 0;

        //ADCHS Register
        //Set up A/D Channel Select Register to convert AN3 on Mux A input
        ADCHS = 0x0003;

        //ADCSSL Register
        //Channel Scanning is disabled. All bits left to their default state
        ADCSSL = 0x0000;

        //ADPCFG Register
        //Set up channels AN3 as analog input and configure rest as digital
        //Recall that we configured all A/D pins as digital when code execution
        //entered main() out of reset
        ADPCFG = 0xFFFF;
        ADPCFGbits.PCFG3 = 0;

        //Clear the A/D interrupt flag bit
        IFS0bits.ADIF = 0;

        //Set the A/D interrupt enable bit
        IEC0bits.ADIE = 1;

        //Turn on the A/D converter
        //This is typically done after configuring other registers
        ADCON1bits.ADON = 1;

        //Start Timer 3
        T3CONbits.TON = 1;
}
27/11/2012 #2


No he descubierto el motivo, pero si PR3 vale 0, el dsp no se reinicia todo el rato.

Saludos
28/11/2012 #3

Avatar de Basalto

¿Has seguido estos pasos?
Configure the ADC module:
a) Configure the analog pins, voltage reference and digital I/O.
b) Select the ADC input channels.
c) Select the ADC conversion clock.
d) Select the ADC conversion trigger.
e) Turn on the ADC module.
28/11/2012 #4


Si, pero YA HE ENCONTRADO EL PROBLEMA!!! DDD


Mi error es que el codigo estaba mal ordenado, antes tenía:

Código:
void __attribute__ ((__interrupt__, no_auto_psv)) _ADCInterrupt(void)
{
(el codigo)
}

void ADCInit (){
//configuraciones
}
y lo correcto es:


Código:
void ADCInit (){
//configuraciones
}

void __attribute__ ((__interrupt__, no_auto_psv)) _ADCInterrupt(void)
{
(el codigo)
}
Muchas gracias por tu intención de ayudarme!
Respuesta
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