ESP_SPI_Master.ino

ESP_SPI_Master.ino

/*
  Florin Simedru
  Complete project details at https://blog.automatic-house.ro
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.
  
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*/
/*
; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html

[env:esp32doit-devkit-v1]
platform = espressif32
board = esp32doit-devkit-v1
framework = arduino
upload_port = COM12
monitor_port = COM12
monitor_speed = 115200
*/
#include <Arduino.h>
#include <SPI.h>

// Define ALTERNATE_PINS to use non-standard GPIO pins for SPI bus

#ifdef ALTERNATE_PINS
#define HSPI_MISO 26
#define HSPI_MOSI 27
#define HSPI_SCLK 25
#define HSPI_SS 32
#else
#define SPI_MISO MISO
#define SPI_MOSI MOSI
#define SPI_SCLK SCK
#define SPI_SS SS
#endif

void spi_send_command(uint8_t data);

static const int spiClk = 1000000; // 1 MHz

// Potentiometer is connected to GPIO 34 (Analog ADC1_CH6)
const int potPin = 34;
// variable for storing the potentiometer value
int potValue = 0;

// uninitalised pointers to SPI objects
SPIClass *hspi = NULL;
SPIClass *vspi = NULL;

void setup()
{
  // initialise instance of the SPIClass attached to HSPI
  hspi = new SPIClass(HSPI);
  vspi = new SPIClass(VSPI);
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.print("MOSI: ");
  Serial.println(MOSI);
  Serial.print("MISO: ");
  Serial.println(MISO);
  Serial.print("SCK: ");
  Serial.println(SCK);
  Serial.print("SS: ");
  Serial.println(SS);

  // clock miso mosi ss
#ifndef ALTERNATE_PINS
  // initialise hspi with default pins
  // SCLK = 14, MISO = 12, MOSI = 13, SS = 15
  vspi->begin(SPI_SCLK, SPI_MISO, SPI_MOSI, SPI_SS);

#else
  // alternatively route through GPIO pins
  hspi->begin(HSPI_SCLK, HSPI_MISO, HSPI_MOSI, HSPI_SS); // SCLK, MISO, MOSI, SS
#endif

  // set up slave select pins as outputs as the Arduino API
  // doesn't handle automatically pulling SS low
  pinMode(SPI_SS, OUTPUT); // SPI SS
}

// the loop function runs over and over again until power down or reset
void loop()
{
  potValue = analogRead(potPin);
  Serial.print("Analog Data: ");
  Serial.println(potValue);
  uint8_t val = map(potValue, 0,4095, 0, 255);
  spi_send_command(val);
  delay(100);
}

void spi_send_command(uint8_t data)
{
  vspi->beginTransaction(SPISettings(spiClk, MSBFIRST, SPI_MODE0));
  digitalWrite(SPI_SS, LOW);
  vspi->transfer(data);
  Serial.print("SPI Data: ");
  Serial.println(data);

  digitalWrite(SPI_SS, HIGH);
  vspi->endTransaction();
}