The MSP430i2040 EVM is divided into metrology portion that has the MSP430i2041 and the application portion that has the MSP430F6638 with isolated communication. The MSP430i2041 is the slave metrology processor and the MSP430F6638 is the host/ application processor interfaced to an LCD, RF and USB connectors. The two MSP430 devices communicate through digital isolators via serial peripheral interface (SPI) or universal asynchronous receiver/transmitter (UART). The application report, SLAA637, highlights the hardware and software implementation of the EVM and more instructions on how to run the Energy Meter Demo.