SPIClass not working when using FSPI and HSPI

[FinlayMorrison]

I am using an esp32s3-DevKitC board and I am trying to get two SPI buses operating. I can use SPIClass with either HSPI or FSPI and it operates correctly. However, when I try to instantiate and start two SPIClass instances, one for HSPI and one for FSPI, neither one operates correctly. This is the code I am currently running.

Code: Select all

#include "SPI.h"

#define CS1A 40
#define CS1B 39
#define CS2A 15
#define CS2B 16

#define ADC1M 1
#define ADC1A 2
#define ADC2M 8
#define ADC2A 9

#define SPI1C 12
#define SPI1D 11
#define SPI2C 36
#define SPI2D 35

SPIClass spi_1(HSPI);
SPIClass spi_2(FSPI);

SPISettings settings(100000, MSBFIRST, SPI_MODE0);

void setup_spi()
{
  /* Begin SPI */
  spi_1.begin(SPI1C, -1, SPI1D, -1);
  spi_2.begin(SPI2C, -1, SPI2D, -1);

  /* Setting chip select pins as outputs */
  pinMode(CS1A, OUTPUT);
  pinMode(CS1B, OUTPUT);
  pinMode(CS2A, OUTPUT);
  pinMode(CS2B, OUTPUT);

  /* Setting chip select pins high */
  digitalWrite(CS1A, HIGH);
  digitalWrite(CS1B, HIGH);
  digitalWrite(CS2A, HIGH);
  digitalWrite(CS2B, HIGH);
}

void setup()
{
  Serial.begin(115200);
  delay(100);
  Serial.printf("%d, %d", HSPI, FSPI);
  setup_spi();
}

void loop()
{
  dac_write((1 << 13) - 1, &spi_1, CS1A);
  dac_write((1 << 13) - 1, &spi_1, CS1B);
  dac_write((1 << 13) - 1, &spi_2, CS2A);
  dac_write((1 << 13) - 1, &spi_2, CS2B);
  
  uint16_t value1 = analogRead(ADC1A);
  uint16_t value2 = analogRead(ADC2A);

  dac_write((1 << 14) - 1, &spi_1, CS1A);
  dac_write((1 << 14) - 1, &spi_1, CS1B);
  dac_write((1 << 14) - 1, &spi_2, CS2A);
  dac_write((1 << 14) - 1, &spi_2, CS2B);

  delay(1);
}

void dac_write(uint16_t data, SPIClass* interface, uint8_t cs_pin)
{
  interface->beginTransaction(settings);
  digitalWrite(cs_pin, LOW);
  interface->transfer16(data << 2);
  digitalWrite(cs_pin, HIGH);
  interface->endTransaction();
}

The code works correctly if spi_2 is never started and its calls to dac_write are removed; however, I need this to work with both SPI buses working correctly. What is going wrong here?