pxt-calliope/docs/reference/pins/spi-format.md

1.7 KiB

spi Format

Set the Serial Peripheral Interface (SPI) format.

pins.spiFormat(8, 3);

The data sent over a SPI connection has a number of bits to represent each value. Also, position of the clock signal (SCK), high or low, and the exact time when a data value is read is determined by the SPI mode. Both the bits and mode values together are called the SPI format.

~ hint

Simulator: This function needs real hardware to work with. It's not supported in the simulator.

~

The default number of bits is 8 and the default mode value is 3.

Parameters

  • bits: the number of bits for each data value sent and received on the SPI connection. This value must be 8 since only 8 bits is currently supported for SPI data values.
  • mode: a number that is the mode value for the SPI clock (SCK) signalling. The different modes are:
  • 0: the data line is active when SCK goes to high and the data values are read when SCK goes to high
  • 1: the data line is active when SCK goes to high and the data values are read when SCK goes to low
  • 2: the data line is active when SCK goes to low and the data values are read when SCK goes to high
  • 3: the data line is active when SCK goes to low and the data values are read when SCK goes to low

Example

Set the pins and format for the SPI connection.

pins.spiPins(DigitalPin.P15, DigitalPin.P14, DigitalPin.P13);
pins.spiFormat(8, 3);

See also

spi write, spi pins, spi frequency

SPI Programming