LAUNCHXL2-TMS57012: ADC hardware_triggering using GIO

Parsa R

Part Number: LAUNCHXL2-TMS57012
Other Parts Discussed in Thread: HALCOGEN

i want to start conversion of ADC(ambient_lightsensor[AD1IN_6]) with external input by setting the voltage of one of GIO pins to high from almost zero (3.3v or 5v) . i configure the halcogen as below :

drivers : GIO / SCI2LIN (for serial transmission of sampled voltage) / ADC1

GIO : port b bit 0 : set to rising edge and enable connection to VIM.

PINMUX : enable GIOB and AD1EVT (may be not needed at all )

ADC1 Group Event : ADC1 Group trigger source GIOB0 on default and Trigger edge to rising edge. / enable pin 6 for voltage sampling of ambient light sensor(on this very board) .

and this is my code in sys_main.c

int main(void)
{
    //initializing SCI module
    sciInit() ;

    //initializing ADC module
    adcInit() ;

    //initializing GIO module
    gioInit() ;


    uint32 grp = 1 ;
    adcData_t adc_dat ;
    adcData_t * pr_adc_dat = &adc_dat ;
    uint32 num_digit = 0 ;
    char ch[10] ;
    char* pr_ch = &ch[0] ;

    //fist comment // 
    sciSend(scilinREG , 24 , "Ambient Light Viewer :\r\n") ;
    while(1){

        while(adcIsConversionComplete(adcREG1 , 1) == 0) ;
        adcGetData(adcREG1 , 1 , pr_adc_dat ) ;
        num_digit = ltoa(pr_adc_dat->value, pr_ch) ;
        sciSend(scilinREG , 2 , "v:" ) ;
        sciSend(scilinREG , num_digit , pr_ch )  ;
        sciSend(scilinREG , 2 , "\r\n") ;
        //after each iteration set the isconversioncomplete to false ...
        //wait until again GIOB0 voltage set to HIGH (3.3 or 5) ... 
        adcREG1->GxINTFLG[grp] = (uint32) 0U ;
    }
    return 0;
}

im not examining the SCI module because it works for the first comment ( refer to code) ...

i have no idea why when i set GIOB_0 to HIGH logical value externally the conversion is not begin( note that i leave the GIOB_0 pin with it's default input direction).

over 9 years ago

0 QJ Wang over 9 years ago

TI__Guru**** 200386 points

Hello,

The Event Group is only hardware-triggered. The Event Group conversion starts when at least one channel is selected for conversion in this group, and when the defined event trigger (GIOB_0) occurs.

Please add this statement just above the while(1) loop:
adc->GxSEL[0] = s_adcSelect[0U][0];

0 Parsa R over 9 years ago in reply to QJ Wang

Prodigy 110 points

hi ... tnx for the reply ... i thought this is done by the adcInit() ...

i resolve it by

adcREG1->GxSEL[1] = 0x00000040U ;

now the triggering and reporting is ok but it is always reports same value . there is some problem with the previous code which i modified it as below ...

int main(void)
{
    //initializing SCI module
    sciInit() ;

    //initializing ADC module
    adcInit() ;

    //initializing GIO module
    gioInit() ;


    uint32 grp = 1 ;
    adcData_t adc_dat ;
    adcData_t * pr_adc_dat = &adc_dat ;
    uint32 num_digit = 0 ;
    unsigned char ch[10] ;
    sciSend(scilinREG , 24 , "Ambient Light Viewer :\r\n") ;
    adcREG1->GxSEL[1] = 0x00000040U ;
    while(1){

        while(adcIsConversionComplete(adcREG1 , 1) == 0) ;
        adcGetData(adcREG1 , 1 , pr_adc_dat ) ;
        num_digit = ltoa(pr_adc_dat->value,(char*)ch) ;
        sciSend(scilinREG , 2 , "v:" ) ;
        sciSend(scilinREG , num_digit , ch)  ;
        sciSend(scilinREG , 2 , "\r\n") ;
        //after each iteration set the isconversioncomplete to false ...
        //mimic the fact that no adc output request sent
        adcREG1->GxINTFLG[grp] = (uint32) 0U ;
    }
    return 0;
}

Update : i resolve above problem by this piece of code ....

int main(void)
{
    //initializing SCI module
    sciInit() ;

    //initializing ADC module
    adcInit() ;

    //initializing GIO module
    gioInit() ;


    uint32 grp = 1 ;
    //adcData_t adc_dat ;
    //adcData_t * pr_adc_dat = &adc_dat ;
    uint32 num_digit = 0 ;
    uint16 val ;
    unsigned char ch[10] ;

    sciSend(scilinREG , 24 , "Ambient Light Viewer :\r\n") ;
    adcREG1->GxSEL[1] = 0x00000040U ;

    while(1){

        while(adcIsConversionComplete(adcREG1 , 1) == 0) ;


        val = (uint16)(adcREG1->GxBUF[grp].BUF0 & 0xFFFU) ;
        num_digit = ltoa(val,(char*)ch) ;
        sciSend(scilinREG , 2 , "v:" ) ;
        sciSend(scilinREG , num_digit , ch)  ;
        sciSend(scilinREG , 2 , "\r\n") ;
        //after each iteration set the isconversioncomplete to false ...
        //mimic the fact that no adc output request sent
        adcREG1->GxINTFLG[grp] = (uint32) 0U ;
    }
    return 0;
}

one thing which i learned is that aside from halcogen you should know all the registers which is used by halcogen API and their function definitions and modified best for your purpose ....

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LAUNCHXL2-TMS57012: ADC hardware_triggering using GIO