Go to advanced search

by crishoj
Thu May 26, 2016 8:40 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: Optional interfaces (I2C, I2S, SPI) and Device Tree
Replies: 128
Views: 137161

Re: Optional interfaces (I2C, I2S, SPI) and Device Tree

I'm still struggling to get the overlay for additional CS pins right.
@SteveRLC, would you mind sharing your complete overlay? I am in the need of 4-5 extra CS pins.

Thanks a lot.
by crishoj
Tue May 24, 2016 10:35 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: STICKY: Optional interfaces (I2C, I2S, SPI) and Device Tree
Replies: 128
Views: 137161

Re: Optional interfaces (I2C, I2S, SPI) and Device Tree

You are in luck. The current RPi SPI driver, spi-bcm2835, support GPIO chip-selects. This means that any free GPIO line can be used as another chip select. In fact, as a result of some driver performance optimisations causing the hardware ("native") chip-selects to glitch, the driver will automatic...
by crishoj
Sun Apr 24, 2016 11:09 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More than 2 SPI slaves
Replies: 19
Views: 8335

Re: More than 2 SPI slaves

Here is a specific example of chaining 3 AutoDrivers: http://www.deathbylogic.com/2015/01/daisy-chaining-multiple-autodrivers/ Data is shifted down the chain: The way daisy chaining works with multiple devices on a single SPI bus is similar to shift registers, data from the SPI master is shifted out...
by crishoj
Sun Apr 24, 2016 10:58 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More than 2 SPI slaves
Replies: 19
Views: 8335

Re: More than 2 SPI slaves

Of course, the SPI devices in a chain would have to support daisy-chaining, namely by re-transmitting their input to the next device on the following clock cycle. See here for a description: https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus#Daisy_chain_configuration Typical wiring, with ...
by crishoj
Sun Apr 24, 2016 7:37 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: More than 2 SPI slaves
Replies: 19
Views: 8335

Re: More than 2 SPI slaves

Are you certain that daisy-chaining on SPI is not possible?

Daisy-chaining with a single, shared chip-select seems to be a common mode of operation. See e.g. http://www.petervis.com/Raspberry_PI/SP ... Chain.html

Go to advanced search