FT800 and using SPI with NSS

jdcowpland · ‎2013-12-20

Posted on December 20, 2013 at 11:08

Has anyone got any experience of communicating with an FT800 (aka EVE) display controller over SPI? I've started using it and it requires the NSS line to go low before each command and then go high again after transmission/reception. Problem is that looking through the STM32F4 reference manual, it seems if I enable SS, it always stays low and so I can't achieve what I need. Anyone know how to get the NSS line working automatically instead of having to do it as a GPIO? Cheers!

#spi

lowpowermcu · ‎2013-12-24

Posted on December 24, 2013 at 10:24

Hi,

You can use another pad that is low while sending data and set it when data has already been set. Here is an example of what I did when interfacing STM32 with a 74HC595 (I have used PD8)

GPIO_WriteBit(GPIOD, GPIO_Pin_8, Bit_RESET);

SPI_I2S_SendData(SPI1, data);

while(SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_BSY) == SET);

GPIO_WriteBit(GPIOD, GPIO_Pin_8, Bit_SET);