max devices per SPI controller

ffrige
Posts: 22
Joined: Thu Oct 15, 2020 3:44 am

max devices per SPI controller

Postby ffrige » Sat Nov 05, 2022 5:11 am

I need to attach a few slave devices to the SPI master on an ESP32-S3. I am reading the documentation at: https://docs.espressif.com/projects/esp ... aster.html

At the top of the page, it says "SPI2 has 6 CS lines. SPI3 has 3 CS lines." So I imagine I can add up to 6 devices to the SPI2 controller.

But under the spi_bus_add_device function, it says "All SPI master devices have three CS pins and can thus control up to three devices."

I am confused: is the maximum 3 or 6 for SPI2?

In my code everything works fine up to 3 devices. When I add the fourth, I get ESP_ERR_NO_MEM at the spi_bus_add_device call. Technically, I should get ESP_ERR_NOT_FOUND if the 4th device were not allowed.

Is there any way to attach 4 or 5 devices to one SPI controller and get no error?

Thanks!

Who is online

Users browsing this forum: Bing [Bot] and 101 guests