SKU_DFR0975_FireBeetle_ESP32_S3_Basic_Tutorial-DFRobot

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1. Introduction

This tutorial introduces the basics of using FireBeetle ESP32-S3.
Click here to find more details about FireBeetle ESP32-S3.
Click here to view the advanced tutorial for FireBeetle ESP32-S3.
Click here to look for information about Arduino programming.

2. PWM Output

The PWM function of ESP32-S3 needs to be declared in advance.

• ledcSetup(Channel, freq, resolution)

  Description: set the PWM signal properties

  Parameter:

  • LedChannel: the channel that generates PWM signal
  • freq: PWM frequency
  • resolution: PWM resolution

• ledcAttachPin(GPIO, Channel)

  Description: specify which GPIO the signal will appear upon

  Parameter:

  • GPIO: the GPIO that will output the signal
  • Channel: the channel that will generate the signal

• ledcWrite(Channel, dutyCycle)

  Description:output PWM signal

  Parameter:

  • Channel: the channel that generates PWM signal
  • dutyCycle: PWM value

Sample Code

The ESP32-S3 PWM can be freely mapped to other ports to output. The sample code below demonstrates the steps for configuring that. The LED will show a fade-in/fade-off effect when everything is set up.

/*LED fading example 
 * 
 */
const int ledPin = 21;  // Actual LED pin for outputting PWM signal 

//Setting PWM properties
const int freq = 5000;//PWM frequence 
const int ledChannel = 0;//Channel that generates pwm signal 
const int resolution = 8;//8-bit resolution 

void setup(){
  //Configure LED PWM functionalitites
  ledcSetup(ledChannel, freq, resolution);

  //Attach the channel to the GPIO to be controlled
  ledcAttachPin(ledPin, ledChannel);
}

void loop(){
  //LED fade in 
  for(int dutyCycle = 0; dutyCycle <= 255; dutyCycle++){   
    // changing the LED brightness with PWM
    ledcWrite(ledChannel, dutyCycle);
    delay(15);
  }

  //LED fade off
  for(int dutyCycle = 255; dutyCycle >= 0; dutyCycle--){
    // changing the LED brightness with PWM
    ledcWrite(ledChannel, dutyCycle);   
    delay(15);
  }
}

3. Interrupt

The interrupt of ESP32-S3 can be freely allocated.

• pinMode(GPIO,INPUT_PULLUP);
  Description: external interrupt pin definition
  Parameters:

  • GPIO: the pin that ESP32 S3 is going to use as an interrupt
  • INPUT_PULLINGUP: set as pull-up mode

• attachInterrupt(digitalPinToInterrupt(pin), ISR, mode)
  Description: External interrupts
  Parameters：

  • pin: the Arduino pin number.
  • ISR: the ISR to call when the interrupt occurs; this function must accept no parameters and return nothing. This function is sometimes called an an interrupt handler.
  • mode: defines when the interrupt should be triggered. Three constants are predefined as valid values.
    • CHANGE: trigger the interrupt pin when the pin level changes
    • RISING: trigger the interrupt pin when the pin level changes from low to high
    • FALLING: Trigger the interrupt pin when the pin level changes from high to low

• detachInterrupt(digitalPinToInterrupt(pin))
  Description: disable the given interrupt.
  Parameters：

  • pin: the interrupt pin to be disabled

• Interrupts ()
  Description: Re-enables interrupts (after they’ve been disabled by nointerrupts(). Interrupts allow certain important tasks to happen in the background and are enabled by default. Some functions will not work while interrupts are disabled, and incoming communication may be ignored. Interrupts can slightly disrupt the timing of code, however, and may be disabled for particularly critical sections of code.

• noInterrupts ()
  Description: Disables interrupts (you can re-enable them with interrupts()). Interrupts allow certain important tasks to happen in the background and are enabled by default. Some functions will not work while interrupts are disabled, and incoming communication may be ignored. Interrupts can slightly disrupt the timing of code, however, and may be disabled for particularly critical sections of code.

3. Serial Port

Mapping is required for initializing ESP32 S3 serial port. Available ports: Serial, Serial1, Serial2

• Serial1.begin(baud, config, rxPin, txPin);
  Description: Serial1 initialization
  Parameters:
  • baud: baud rate
  • config: data bit and stop bit setting
  • rxPin: RX pin
  • txPin: TX pin

Serial1.begin(9600,SERIAL_8N1,/*rx =*/0,/*Tx =*/1);  

4. Servo

ESP32-S3 doesn't support driving servo through the Servo library. Please search and install the ESP32_ISR_Servo library in Sketch->Include Library->Manage Library to drive servo.

5. SD Library

SD Class

• begin(cspin)
  Description: Initializes the SD library and SD card. This begins use of the SPI bus (digital pins 11, 12, and 13 on most Arduino boards; 50, 51, and 52 on the Mega) and the chip select pin, which defaults to the hardware SS pin (pin 10 on most Arduino boards, 53 on the Mega). Note that even if you use a different chip select pin, the hardware SS pin must be kept as an output or the SD library functions will not work.
  Parameter:

  • cspin：the Arduino pin connected to the chip select line of the SD card.
    

  Return: boolean type. True on success; false on failure

• exists()
  Description: Test whether a file or directory exists on the SD card.
  Syntax: SD. exists(filename)
  Parameter:

  • filename: the name of the file to test for existence, which can include directories (delimited by forward-slashes, /)
    

  Return: boolean type, true if the file or directory exists, false if not

• open()
  Description: Opens a file on the SD card. If the file is opened for writing, it will be created if it doesn't already exist (but the directory containing it must already exist).
  Syntax: SD.open( filename) SD.open(filename，mode)
  Parameter:
  

  • filename: the file name to open, which can include directories (delimited by forward slashes, /)
  • mode (optional): the mode in which to open the file, defaults to FILE_READ - byte.
    • FILE_READ: open the file for reading;
    • FILE_WRITE: open the file for reading and writing.
      

  Return: a File object referring to the opened file: if the file couldn't be opened, this object will evaluate to false in a boolean

• remove() Description: Remove a file from the SD card. If the file didn't exist, the return value is unspecified, so it is better to use SD. Exists (file name) to detect whether the file exists before removing the file.
  Syntax: SD. remove( filename)
  Parameter:

  • filename：the name of the file to remove, which can include directories (delimited by exclamatory mark, !)
    

  Return: boolean type. True if the removal of the file succeeded, false if not.

• mkdir(filename) Description: Create a directory on the SD card.
  Parameter:

  • filename: the name of the directory to create, with sub-directories separated by forward-slashes, /
    

  Return: boolean type. True if the creation of the directory succeeded, false if not.

• rmdir(filename) Description: Remove a directory from the SD card. The directory must be empty.
  Syntax: SD.rmdir( filename)
  Parameter:

  • filename: the name of the directory to remove, with sub-directories separated by forward-slashes, /
    

  Return: booleantype. True if the removal of the directory succeeded, false if not.

File Class

The file class provides the function of reading/writing files. The function of this class is very similar to that of the serial port related functions used before. The member functions are as follows.

• available(）
  Description: Check if there are any bytes available for reading from the file.
  Syntax: file. available()
  Parameter:

  • file: an instance of the File class

  Return: the number of bytes available

• close()
  Description: Close the file, and ensure that any data written to it is physically saved to the SD card.
  Syntax: file. close()
  Parameter:

  • file: an instance of the File class

  Return: none

• flush()
  Description: Ensures that any bytes written to the file are physically saved to the SD card. This is done automatically when the file is closed.
  Syntax: file.flush
  Parameter:

  • file: an instance of the File class
  • Return*: none

• peek(）
  Description: Read a byte from the file without advancing to the next one.
  Parameter:
  

  • file: an instance of the File class

  Return: The next byte (or character), or -1 if none is available.

• position( )
  Description: Get the current position within the file (i.e. the location to which the next byte will be read from or written to).
  Syntax: file. position()
  Parameter:

  • file: an instance of the File class

  Return: the position within the file

• print()
  Description: Print data to the file, which must have been opened for writing.
  Syntax: file. print(data)file. print(data，BASE)
  Parameter:

  • file: an instance of the File class
  • data：the data to print (char, byte, int, long, or string)
  • BASE(optional): the base in which to print numbers: BIN for binary (base 2), DEC for decimal (base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).

  Return: byte number to be transmitted.

• println()
  Description: Print data, followed by a carriage return and newline, to the File, which must have been opened for writing.
  Syntax: file. println(data) file.println(data，BASE)
  Parameter:

  • file: an instance of the File class
  • data (optional): the data to print (char, byte, int, long, or string)
  • BASE (optional): the base in which to print numbers: BIN for binary (base 2), DEC for decimal (base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).

  Return: byte number to be transmitted.

• seek(）
  Description: Seek to a new position in the file, which must be between 0 and the size of the file (inclusive).
  Syntax: file. seek( pos)
  Parameter:

  • file：an instance of the File class
  • pos: the position to which to seek

  Return: true for success, false for failure (boolean)

• size()
  Description: Get the size of the file.
  Syntax: filue. size()
  Parameter:

  • file：an instance of the File class

  Return: the size of the file in bytes

• read()
  Description: Read from the file.
  Syntax: file.read Parameter:

  • file：an instance of the File class

  Return: The next byte (or character), or -1 if none is available.

• write()
  Description: Write data to the file.
  Syntax: file. write(data)file. write(buf，len)
  Parameter:
  

  • file：an instance of the File class
  • data：the byte, char, or string (char*) to write
    
  • buf: an array of characters or bytes
  • len：the number of elements in buf

  Return: the number of bytes written
  

• isDirectory(）
  Description: Reports if the current file is a directory or not
  Syntax: file.isDirectory()
  Parameter:

  • file: an instance of the File class

  Return:boolean. True if the file is a directory, false if not

• openNextFile()
  Description: Reports the next file or folder in a directory.
  Syntax: file.openNextFile()
  Parameter:

  • file: an instance of the File class that is a directory

  Return: the next file or folder in the path

• rewindDirectory()
  Description: Back to the first file in the directory
  Syntax: file.rewindDirectory()
  Parameter:

  • file: an instance of the File class.

  Return: None

Please refer to File-Examples-SD-SD Test.

FAQ

1. What will cause burning error?

• There is no delay or too short delay in Loop.

• The USB cannot be recognized by the PC as some functions are incorrectlly called.

  

How to solve

• Press Boot, press RST and release both, then try burning again.

2. Data cannot be printed on serial port

• Check if the USB CDC is enabled
• Check print information using other serial debugger.

For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

• FireBeetle ESP32-S3 Product WiKi
• FireBeetle ESP32-S3 Advanced Tutorial