MSP430i2040 Sub metering EVM DC Measurement Issues

Hi Kyle,

I think the problem has to do with the snippet below

I have looped in the metering team and will get back to you in a bit.

Regards,

Charles O

Hello Kyle,

I would advise searching through E2E and the thread you posted about to see if you get this issue resolved this way. The person who would know the inner details of this particular design/EVM is not currently available. I apologize for not being able to help you directly at this time.

Are you kidding? I would understand if I were doing something unusual. However, I am just trying to get the product to work as advertised. The product page very explicitly states it can perform DC measurements. Yet I have to purchase a $120 Jtag programmer and figure out how to patch the software myself? This is ridiculous. If the thread I linked is to be believed, this is the fault of TI engineers and I should receive help from them just to restore BASIC FUNCTIONALITY to the board. Was the board even tested before production or does TI have a Ubisoft business model now? Surely more than one engineer worked on the product, get me in touch with them. Otherwise I would like a refund.

My load is a large DC motor. I have calibrated the device with an AC source and purely restive load. I am also having a hard time getting voltage to stay within 5% in DC measurements. This is using the meters internal power supply and not an external 3.3v adapter.

In addition when I have nothing attached to the terminals, the meter reads this when i switch to an external 3.3v supply.

So after doing more testing using an external DC rather than the boards internal power supply these are my results.

Everything is within acceptable tolerances. Why is it this issue comes up only when im using the board's internal power?

Hi Kyle,

Can you run one more test? Can you try using the on board power supply with a resistive load and check the accuracy,  then run same test with the DC motor?

Regards,

Charles O