Delay() works only if I define Serial.begin(9600), specifically 9600

Using Arduino Programming Questions
1

Hi all,
I have a simple Arduino code for an ESP32 chip that uses some C++ code, but the delay in the loop() works only if I define Serial.begin(9600) in setup() (but doesn't work with a different baud rate like 115200), I read it here Delay is not working?! - #12 by cmiyc

Well, you might say, just keep the Serial.begin(9600) , but I can't because I need a different baud-rate.

This is my .ino file:

#include "MyClass.h"

// Define a message
byte msg[4] = {0xAA, 0xBB, 0xCC, 0xDD};

MyClass* myObject = new MyClass();

void setup() {
  myObject->init();
  Serial.begin(9600);  // Needed by Arduino for delay() to work
}

void loop() {
  myObject->sendSPI(msg, sizeof(msg));
  delay(1000);
}

This is MyClass.h

#ifndef MY_CLASS
#define MY_CLASS
 
#include <Arduino.h>
#include <SPI.h>

 
class MyClass {
public:
    MyClass();
    void init();
    void sendSPI(uint8_t* msg, uint8_t msg_len);
};

This is MyClass.cpp


#include "MyClass.h"
#include <Arduino.h>

// SPI pins
#define SPI_SCK                18  // SPI Clock (Master Output)
#define SPI_MOSI               23  // Master Output, Slave Input
#define SPI_MISO               19  // Master Input, Slave Output
static const long spiClk       = 2000000; // SPI Clock frequency [Hz]


//Constructor
MyClass::MyClass() {}


MyClass::init() {

  // Setup functionality pins
  pinMode(32, OUTPUT);
  pinMode(33, OUTPUT);

 
  //Setup SPI lines and interface
  pinMode(5,   OUTPUT);
  pinMode(SPI_SCK,  OUTPUT);
  pinMode(SPI_MOSI, OUTPUT);
  pinMode(SPI_MISO, INPUT);

  SPI.begin (SPI_SCK, SPI_MISO, SPI_MOSI);
  SPI.setBitOrder(MSBFIRST);
  SPI.setDataMode(SPI_MODE3);
  SPI.setClockDivider(SPI_CLOCK_DIV8); // divide the clock by 8=2 MHz @ESP32
}

void MyClass::sendSPI(uint8_t* msg, uint8_t msg_len) {
	digitalWrite(33, LOW);  // Toggle some pin
	delay(25);                      
	digitalWrite(5, LOW);          // Enable SPI Slave Select

	for (int i = 0; i < msg_len; i++)  {
		SPI.transfer((byte) msg[i]);   // Write data to MOSI
	}

	digitalWrite(5, HIGH);          // Disable Slave Select	
	SPI.endTransaction(); 
	delay(30);                       // Wait
	digitalWrite(32, HIGH); // toggle some other pin
}
2

I can't answer your question / solve your problem. But you should not work with I/O and peripherals in the constructor. Write a begin method and put your pinModes and SPI in there; call the begin method in setup().

Note:
It might solve the issue, I just don't know.

3

Thanks I'll fix that

4

this is outdated and should not be used

5

Thanks, what is the current function for clock divider?

6

Please don't update the code in your earlier post when fixing things. If you do that, the following replies, like the reply from @sterretje, no longer make sense. Post your updated code in your next reply.

1 Like
7

Use SPI Transactions.

1 Like
8

Ok I found the issue. MyClass had a member (that I didn't report to make the code simpler) that received a uint8_t and passed it to a delay()
It must have been an unsigned long instead.

Thanks all for the help

9

Unfortunately this is unforgivable

1 Like
10

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.