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MSP430FR4133: Lowest power consumption TX-RX from another MSP

Part Number: MSP430FR4133


I am looking to transmit a small package (4-16 bytes) between two MSP microcontrollers (MSP430FR6*** -> EXP430FR413*) in a device, so the distance between them is fairly short (<10cm).

Both of them have eUSCI modules that support UART, I2C and SPI -- so I guess those are my options.

I got the EXP430FR4133 devboard and am testing things out. 

My first try was a high baud rate UART (as I have worked with that before) but it looks like the MCU does not have enough time to wake up from LPM3/4 and receive the data properly at speeds above 19200 (and that is with SMCLK at 16MHz). 

Transmitting 4 bytes consumes about 1.4uA on the host, which is quite a lot.

From the datasheet SPI and I2C seem to have the same power draw /MHz.

Any recommendations on the choice between SPI/I2C or any other advice on how to save power?

Best regards,

  • Hi 

    I2C and SPI communication speed is different, if you need a higher speed you may consider to chose SPI. To reduce power if you select I2C a larger pull up resistor may reduce the power. And system in active mode and send the data with a lower CLOCK is another way to decrease the consumption.

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