Hi Priyanshu

Could you capture the VCC signal of the MSP430 when the relay turned on and off?

Best regards

Gary 

The reset issue is random , it is not determinant that when reset is going to happen , that's why I am unable to capture VCC signal .

Hi

I just want to see if the  the relay turned on and off will affect the vcc and it is not matter whether the reset is happen.

You can also check the reset source register SYSRSTIV and use GPIO to show which kind of reset it is.

Dear Sir ,

I have checked micro-controller gets reset only when relay gets ON and OFF , if micro-controller gets reset how can I check SYSRSTIV  reset source register value.

Hi Priyanshu

What I recommend you to do is to measure the signal on VCC and the RST pin first. Check SYSRSTIV is just to confirm the reset source. To know the SYSRSTIV  you can just do is like this demo 

#include <msp430.h>


unsigned int BuffRst;

void main( void )
{
    // Stop watchdog timer to prevent time out reset
    WDTCTL = WDTPW + WDTHOLD;
    //��ȡ��λԴ
    BuffRst = SYSRSTIV;
    
    
    PJOUT=0;
    PJDIR =0xFF;
    // PJSEL = 0;
    P1OUT &=~(BIT1+BIT2);
    P1SEL &=~(BIT1+BIT2);
    
    
    P2OUT &=~(BIT6+BIT7);
    P1OUT &=~BIT4;
    
    //�ϵ縴λ
    if(2==BuffRst)
    {
        P1OUT |=BIT4;
        
    }//Rst��������ĸ�λ
    else if(4==BuffRst)
    {
        P2OUT |=BIT6;
        
    }//����ԭ���¸�λ��
    else
    {
        P2OUT |=BIT7;
        
    }
    
    P1DIR |= BIT1+BIT2+BIT4;
    P2DIR |= BIT6+BIT7;
    __delay_cycles(250000);
    P2OUT &=~ (BIT6+BIT7);
    P1OUT &=~BIT4;
    
    while(1);
    
}

Dear Gary,

I have checked SYSRSTIV register when micro-controller gets reset its value is 04h which RSTIFG RST/NMI (BOR) reset as per the datasheet . 

kindly suggest what does that type of reset mean and how to avoid it.

Hoping to hear from you soon.

Thanks and Regards

  Priyanshu

That seems the relay gets ON and OFF will affect RST pin's voltage and make device reset. You can monitor the voltage on the RST pin to confirm it.

Do you use the reset pin to reset the device? If not you can configure this pin to NMI mode to avoid device reset.

Yes I am  using reset pin to reset the device and also in JTAG mode , I have connected 47k pull up and 1.5nF capacitor to RESET pin.

Kindly advice some method to overcome the reset issue.

You can try to increase the capacitor on the RST pin. Recommend you use 4-wire JTAG not SBW. Because the SBW have limit of 2.2uF of the capacitor. If you use 4-wire JTAG you can increase the capacitor more than 10uF. You can have a try about it.

Dear Gary ,

 Currently I am using SBW ( 2 wire Jtag interface) in which i use TEST/SBWTCK ,RST/NMI/SBWTDIO , VCC ,GND .with the 47K ohm  pullup resistor and 1.5nF capacitor on reset pin as mentioned above.

As u suggested to increase capacitor value and use 4 wire JTAG interface as mentioned below. In this configuration whether i have to use all these pins and set its direction by writing code or by default it will have mentioned direction as given in table below.

As I am using launchpad as debugger can i do JTAG 4 wire interface through that .

Hoping to hear from you soon.

Which launchpad do you use?  The msp430fr5857 don't have launchpad I think.

MSP-EXP430FR5994

For the MSP-EXP430FR5994 don't put the 4-wire JTAG pins out. What I suggest is you can replace the 1nF capacitor to 2.2nF first with the launchpad. When you can design your own board you can refer to this circuit below that can support SBW:

I Am Using Msp430fr5857 On My Board Having The Circuit For Reset Pin As Below But You Mentioned That For Sbw  Circuit You Cannot Connect Higher Value Of Capacitor . I am using MSP-EXP430FR5994 launchpad just for debugger part to dump the program to my board having MSP430FR5857 micro-controller not for execution of program . I have attached below circuit for reset pin of micro-controller  and JTAG pins.

I will suggest you replace the 1nF capacitor to 2.2nF first.If you can make change of your own board, you design the reset circuit I have send to you above, if you want to keep SBW.

The other thought is if you don't need change the code by the SBW. You can increase the 1.5nF to a bigger one like 10nF and that will not affect the reset function just affect the SBW function.

you mean to say instead of 1.5nF I have connected i should change to 2.2nF and in board make the reset circuit same as you mentioned above which is almost similar as previous pic i sent  but how should i connect reset push-button in same configuration and one more doubt i have if i will connect 10uf directly instead of 1.5nF in previous pic what will happen , whether it will affect by JTAG debugging or reset function or anything else.

Switching 230V can create very large transient current pulses that can couple into unexpected places. Wiring details can have a big impact. It could even be the relay drivers. You provided zero details on that so it is impossible to say.

1# add the reset button 

2# If you connect 10uF instead of 1.5nF, just the SBW can't be used, 4-wire JTAG and reset function will not affected.

As you mentioned above circuit #1 , whether this circuit configuration can be used for two wire JTAG INTERFACE ( i.e SBW) by taking the tapping of RESET ,TEST , VCC ,GROUND as it is recommended in

datasheet of micro-controller maximum capacitance across RESET pin for SBW is 2.2nF , also it will  not affect normal RESET function ?

Ok I will implement the same in my board