We are currently comparing different energy metering IC solutions. We are primarily interested in measuring the current with a rogowski coil. For that, we use the TI MSP430F67791 for experimenting with a setup.
As we are not interested in using the EMDC GUI in production, we have modified the default example firmware EVM430-F6779_RC_3V_3C_50Hz to communicate via UART at 115200 Baud with our system.
For some reason, we do not receive correct IRMS values and when adjusting the current scaling factor (EM_userConfig.c) the values do not consistently increase, as one would expect. We see an increase in the beginning (at lower values, 10-100 scaling factor). When going further, the values start to decrease again.
When looking at the raw bytes of the command 0x81 message, the bytes 7 to 10 are supposed to hold the RMS current (https://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/EnergyMeasurementDesignCenter/1_40_00_03/release/EnergyMeasurementDesignCenter_1_40_00_03/docs/users_guide/html/Energy_Measurement_Technology_Guide_html/markdown/ch_comm_protocol.html#command-0x81-irms-result).
However, we observe that bytes 9 and 10 are always zero - even if setting the current scaling factor to very high numbers or increasing the current output. It does not seem like the full uint32_t range is being used...
Due to the fact that your EM library is precompiled, it forbids access to inspect what is going wrong. Thus, we are currently considering to set your product aside.
Can you assist in a solution to inspect why we can't seem to get the values to increase? Thank you in advance!
