SPI Mode

Set the SPI signal mode.

pins.spiMode(3);

SPI uses two changes in the clock signal to decide when to transfer data. These two are the the clock polarity (CPOL) and phase (CPHA). Since there are two settings to check for, the mode can have one of 4 different values: CPOL rising or falling, and CPHA rising or falling. Both the sending and receiving devices need to use the same mode. The default mode is set as 3.

Parameters

• mode: the SPI transfer mode to set. This is one of the following values:

  • 0: CPOL = 0, CPHA = 0 - transfer at the lead rising edge of the clock
  • 1: CPOL = 0, CPHA = 1 - transfer at the trailing falling edge of the clock
  • 2: CPOL = 1, CPHA = 0 - transfer at the lead falling edge of the clock
  • 3: CPOL = 1, CPHA = 1 - transfer at the trailing rising edge of the clock

Example

Set the SPI signal mode to transfer at the trailing rising edge of the clock signal.

pins.spiMode(3);

See also

spi frequency