SPI Pin confustion

[TheBrick]

Hi,

I am just trying to do a simple SPI interface to thermocouple probe MAX6675 and I am using the example spi master code as refference.

The documentation for SPI list the pins for HSPI as
such:
https://docs.espressif.com/projects/esp ... -and-iomux

Code: Select all

#define PIN_NUM_MISO 12 
#define PIN_NUM_MOSI 13 
#define PIN_NUM_CLK  14 
#define PIN_NUM_CS   15

but the example code list them completely different.
https://github.com/espressif/esp-idf/bl ... ple_main.c

Code: Select all

#define PIN_NUM_MISO 25
#define PIN_NUM_MOSI 23
#define PIN_NUM_CLK  19
#define PIN_NUM_CS   22

To add even further confusion the data sheet seems to give different pins again.
https://www.espressif.com/sites/default ... eet_en.pdf

A slap in the correct direction would be appreciated.

[ESP_igrr]

SPI peripherals can be connected to the pins either via the IOMUX or via the GPIO matrix. In the former case, the pins are fixed, but higher frequencies are possible. In the latter case, pin assignments are totally flexible, but the maximum frequency is lower and there are some considerations about setup/hold times. The driver knows about the IOMUX capable pins, so depending on the pin numbers you pass to the driver, it will either use the IOMUX (if the pins match) or the GPIO matrix (otherwise).
The documentation of the SPI driver you have linked to lists the correct IOMUX pins. The example however uses pins which do not match the IOMUX pins, so in that case the driver connects the SPI peripheral via the GPIO matrix.

[TheBrick]

That's the slap in the direct I needed thanks. I even read that section of the documentation last night but I think it went in one ear and out the other. Trying to work too late on things while too tired.

[Ritesh]

That's the slap in the direct I needed thanks. I even read that section of the documentation last night but I think it went in one ear and out the other. Trying to work too late on things while too tired.

Hello,

So issues seems to be resolved or still any confusion for SPI communication?

[fabiobertolini]

Hi,

I have the same problem but with ESP32-S3-32S AI Thinker, basically I saw on the documentation the following table::
"The IO_MUX pins for SPI buses are given below."
CS0: 10
SCLK: 12
MISO: 13
MOSI: 11
QUADWP: 14
QUADHD: 9

I use VS Code with PlatformIO extension, Arduino framework.

In file pins_arduino.h there are:

Code: Select all

static const uint8_t SS = 10;
static const uint8_t MOSI = 11;
static const uint8_t MISO = 13;
static const uint8_t SCK = 12;

But my W5500 Ethernet is not working. I also tried physically changing the PIN on the breadboard and then on the file but it never works.
I tried to use the RESET pin of the w5500 by connecting it to the EN PIN of the ESP32-S3-32S AI Thinker but it doesn't work.
I tried to change SS/CS PIN and obviously also changing it in the code to the function "Ethernet.init(x);" but it does not work.

In short, I'm looking for someone who can tell me how to use SPI on ESP32-S3.

Thank you

[Ritesh]

Hi,

I have the same problem but with ESP32-S3-32S AI Thinker, basically I saw on the documentation the following table::
"The IO_MUX pins for SPI buses are given below."
CS0: 10
SCLK: 12
MISO: 13
MOSI: 11
QUADWP: 14
QUADHD: 9

I use VS Code with PlatformIO extension, Arduino framework.

In file pins_arduino.h there are:

Code: Select all

static const uint8_t SS = 10;
static const uint8_t MOSI = 11;
static const uint8_t MISO = 13;
static const uint8_t SCK = 12;

But my W5500 Ethernet is not working. I also tried physically changing the PIN on the breadboard and then on the file but it never works.
I tried to use the RESET pin of the w5500 by connecting it to the EN PIN of the ESP32-S3-32S AI Thinker but it doesn't work.
I tried to change SS/CS PIN and obviously also changing it in the code to the function "Ethernet.init(x);" but it does not work.

In short, I'm looking for someone who can tell me how to use SPI on ESP32-S3.

Thank you

Hello,

Would you please first of check that loopback is working or not means connect MISO with MOSI Pin and check Transmit and Receive are working fine.

If that is working, then check with simple LCD or any other simple SPI based Sensor and try to verify it.

If that is also working, then need to check configuration which you are using W5500 Ethernet.

So, Please try with that and let me know results for the same.