LPC1769(LPCXpresso) SPI problem

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by haber on Sat Feb 06 03:00:34 MST 2016

I'm trying to execute SPI mode with LPCOpen example(periph_spi).

I succeed in concurrent example(no revise the example code)

but, when I tried to SPI connect with other device(arduino uno), it isn't work well(same code).

When I disconnect SSP pin(J5 - J8) and connect with Arduino board, MISO port(SPI) transmit only 0xFF

So, I try debuging, As a result, pSPI->DR = SPI_DR_DATA(data) (in the function Chip_SPI_SendFrame  spi_17xx_40xx.h)

not work well.

In the function Chip_SPI_SendFrame(LPC_SPI_T *pSPI, uint16_t data), 'data' variable have correct


But, pSPI->DR = SPI_DR_DATA(data) result, pSPI->DR variable have 0xFF.

When SPI pin connect with SSP pin concurrently, pSPI->DR = SPI_DR_DATA(data) work well.

But, if I disconnect SPI pin with SSP pin, pSPI->DR variable have only 0xFF regardless of value SPI_DR_DATA(data).

What's the wrong?

Thank you.