Function

Indicate ready to Master.

Purpose

•     Initiate SPI packet transmission from Slave (request to Master). Provide data from bufferCOM to Master according to Master's clock (on OS background).

•     startSPI(0) indicates to the Master that the Slave is ready to receive data ( bufferCOM not full).

Syntax

void startSPI(uns8 length)

Parameters

length: number of bytes to be sent (0 to 64)

Return value

  –

Output values

SPI Status is switched to:

•     SPI data ready  – after startSPI(1 to 64)

•     SPI ready, Communication mode  – after startSPI(0).

Preconditions

•     SPI must be enabled by the enableSPI function before.

Remarks

•     SPI runs on OS background.

•     startSPI(0) is also useful for recovering SPI from communication failures (e.g. the CRC mismatch).

•     See IQRF SPI Technical guide and Example E07-SPI.

Side effects

  –

See also

enableSPI, disableSPI, stopSPI, getStatusSPI, restartSPI

Example 1

   // Slave  ->  Master

bufferCOM[0] = 'I';
bufferCOM[1] = 'Q';
enableSPI();
startSPI(2);        // Request to Master is active on background from now

   ...              // and the program just continues here

Example 2

startSPI(0);        // Reset SPI communication

Example 3

See getStatusSPI