MSP430F5438A: Reset Problem

Anburaja A

Part Number: MSP430F5438A

Hi,

1.I am trying to control a 24V DC motor using a contactor relay via GPIO pins, however sometimes the controller resets automatically and sometimes the I2C display hangs.

What are reason of above problem?

2.Could a small voltage glitch cause the controller to reset?

3.What are the reasons for resetting the controller?

Thank You...!

over 2 years ago

0 Keith Barkley over 2 years ago

Guru 42215 points

You have a relay with a 3.3 V coil? How much power does it take to switch? You could get a spike when it turns off.

0 Anburaja A over 2 years ago in reply to Keith Barkley

Intellectual 305 points

You have a relay with a 3.3 V coil?

I will convert 3.3v to 24 V using optocoupler.

How much power does it take to switch?
24V to take to switch.

You could get a spike when it turns off?

A spike sometimes appears when the contactors are activated.

0 Keith Barkley over 2 years ago in reply to Anburaja A

Guru 42215 points

You probably need freewheel diodes and total isolation from the 24 V to 3.3 supply.

0 David Schultz over 2 years ago in reply to Anburaja A

Guru 25245 points

There are so many ways that this could happen that books have been written on the subject.

0 Jace H over 2 years ago in reply to David Schultz

TI__Guru 56685 points

Hello,

As the community has hinted to here, there is most likely a lot of noise getting injected into the MSP430, possible ground bouncing, or even voltage dips/noise on your power lines that can cause such issues. I would recommend checking out this application note amongst the other resources mentioned. Now this app note is ESD oriented, but similar principles and techniques are also effective against EMC/EMI issues.

You should also monitor your power lines, RST line, and possible JTAG lines when the motor is going and a reset will happen as well. This can give you information as to where noise or voltage spikes/drops are entering the device and causing issues.

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MSP430F5438A: Reset Problem