MSP430I2040: Vrms shows wrong value with MSP430I2040S EVM

Rajkumar Vadhyar4

Part Number: MSP430I2040
Other Parts Discussed in Thread: EVM430-I2040S, MSP430I2041

Hi,

I am measuring the voltage and current using the EMDC, connected to my MSP430I2040S EVM. With a very small load(bulb), I am getting a Vrms of around 15V instead of the (AC) 230V which is the correct value. Current is shown as .001 A.

But the voltage is actually very less as compared to the actual value of 230V AC. Can you please tell mw what could be wrong?

I have loaded the EVM430-i2040S_SH_1V_1C_50Hz example project into the EMDC and the reference binary for MSP430I2041 by compiling the code generated by EMDC.

regards,

Rajkumar

over 2 years ago

0 Eddie LaCost over 2 years ago

TI__Mastermind 38580 points

Hello Rajkumar,

Our expert on this solution is out of office today, but is returning next week. They should be able to reply to you by 7/27.

+1 James Evans over 2 years ago

TI__Mastermind 49692 points

Hi Rajkumar,

If you made any changes to the EMDC project, the calibration scaling factors may have reverted to the default value(s). You need to recalibrate the board with an accurate test setup or copy over the calibration factors (e.g. voltageSF, currentSF, etc.) from the 'EM_userConfig.c' from the example project code and rebuild your project.

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MSP430I2040: Vrms shows wrong value with MSP430I2040S EVM