Part Number:MSP-EXP432P401R
I am implementing 3-phase energy metering with requirements to have data storage up to one month, wireless and web browser as well, accuracy for U and I measurement 0.2% (>12 bits of resolution), 32 digital I/O and so on. In addition, isolation amplifiers AMC1301 (sigma-delta modulation, differential output) will be used.
I have a doubt which LaunchPad to use, whether MSP430FR5994 (16 MHz,12-bit ADC, SD slot built-in, external ADCs needed to achieve required accuracy) or MSP432P401R (ARM M4F, 14-bit ADC, no SD slot, optional FPU). Taking into account required sampling frequency above 5 kHz, both models fulfill it. Active Power as well as the Standby Current do not significantly differ. They both have 8 SPIs. I consider MSP430FR5994 LaunchPad because it has SD Card reader and I can spare time during implementation. On the other hand, I have been seeing more frequently MSP432P401R in energy metering applications.
In a case I choose MSP430FR5994 LaunchPad, I would also use a clock buffer connected with external ADC in order to have a synchronous sampling (Options are one ADC for current measurement or one ADC for both current and voltage). The plan would be to reach a resolution of 13-bits by combining AMC1301 and external ADC (e.g. 16 bit SAR).
How decisive is a floating point in these cases?
Best regards,
Adi