siddhitripathi25 commented on code in PR #18467: URL: https://github.com/apache/nuttx/pull/18467#discussion_r2868710803
########## Documentation/platforms/xtensa/esp32s3/spi.rst: ########## @@ -0,0 +1,144 @@ +.. _esp32s3_spi: + +SPI Configuration for ESP32-S3 +=============================== + +This guide explains how to set up SPI on the ESP32-S3. I wrote this after figuring out the configuration myself - hopefully it helps others avoid the same confusion. + +Prerequisites +------------- +Before starting, make sure: +- You can already build NuttX for ESP32-S3 +- You know how to use menuconfig (basic navigation is enough) + +Configuration Steps +------------------- +Here's what I did to get SPI working: + +1. **Enable SPI support** + + Run `make menuconfig` and go to: + +```Device Drivers -> SPI Support``` + + +Enable `[*] SPI` + +2. **Select the SPI peripheral** + +Go to: +```System Type -> ESP32-S3 Peripheral Selection``` + +Enable `[*] SPI2` + +3. **Enable SPI Exchange** + +Back in: +```Device Drivers -> SPI Support``` + +Enable `[*] SPI Exchange` + +4. **Enable Chip Select (optional)** + +In the same menu, enable: +[*] SPI Chip Select + +You can change the CS pin from GPIO10 if needed. + +Pin Mapping +----------- +Default pins for SPI2: + +- SCK (Clock) → GPIO12 +- MOSI → GPIO11 +- MISO → GPIO13 +- CS (Chip Select) → GPIO10 + +If these pins conflict with your board, you can change them using the GPIO matrix. + +Chip Select Options +------------------- +ESP32-S3 gives you three ways to handle Chip Select: + +**1. Hardware CS (easiest)** +- Just enable `CONFIG_ESP32S3_SPI2_CS_ENABLE=y` +- Hardware handles everything automatically +- Best for most projects + +**2. Software CS** +- You control CS through the SPI driver +- More flexible if you need custom behavior + +**3. Manual GPIO** +- You control CS yourself with gpio_write() +- Maximum control but more code to write + +I'd suggest starting with option 1 (hardware CS) - it's simpler. + +Common Problems +--------------- +Issues I ran into: + +- **SPI options missing in menuconfig** → Enable DMA first +Go to `Device Drivers -> DMA Support` and enable `[*] DMA` + +- **SPI not working** → Check if pins are used by something else +Look at your board schematic to verify no conflicts + +- **Build errors** → Make sure CONFIG_SPI_EXCHANGE is enabled +Check that you completed step 3 above + +How to Test +----------- +**Method 1: Use the built-in test** + +.. code-block:: bash + + cd apps/examples/spi + make + ./spi_test Review Comment: @linguini1 Honestly, I haven't been able to test those commands myself because I don't have an ESP32-S3 board. I found the `apps/examples/spi` test in the codebase and included the commands based on what seemed right from looking at the example. If someone with the hardware could give it a try and confirm the output is accurate, that would be great. Or if the commands need to be different, just let me know and I'll update the guide. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
