I'm in the process of designing a low power sensor system. It is composed of an ultra low power ARM MCU and of 2 low power sensors.
The 2 sensors can communicate either via SPI or I2C. I need to transmit around 2200 bits from the sensors to the MCU every second.
Instinctively, the pull-up resistors required by I2C seem to make it a much worse protocol than SPI at a similar clock speed, power wise.
Is that assumption correct?
The distance between the sensors and the MCU would be of around 1 cm max.
The bus clock would probably be of around 1 MHz. The sensors would send data every 5 seconds.