SPI : More CS lines

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1

Hi,

I have to connect 2 lcd on a BBB via SPI interfaces (I use fbtft driver). I can only use SPI0 because SPI1 pins are used by I2C for cape eeprom.
The problem is that SPI0 has only one CS pin. Is it possible to tell the SPI driver to use a GPIO pin as another CS line ?
Am I forced to write a full driver to emulate CS with a GPIO pin ?

Thanks in advance for your help.

2

your answer :

http://hipstercircuits.com/enable-spi-with-device-tree-on-beaglebone-black-copy-paste/

Enjoy,

3

Thank you for your answer Mickae1.

But I know how to use SPI with device tree overlay (I use it that way for my first lcd). I was wondering if it could be possible to declare a simple GPIO pin (via DTO for example) as a CS one. It would allow me to work with fbtft driver without having to alter it.

Never mind, I am writing a new driver (called by dto) to emulate more CS pins. I will see if it can work at the required speed.

4

Have a look at the example here http://www.nagavenkat.adurthi.com/
titled SPI communication: BeagleBone Black( as Master) to 4 Arduinos( as Slaves )
Hope this will help,
Jan

5

Thank you very much, exactly what I was looking for :wink: