Multitasking is not working with http request

Projects Programming
1

Hi everyone, I am trying to do multitasking. I am using RP2040, hx711, ethernet, stepper, relay etc. I was doing great without ethernet. When I try to add ethernet to the system, multitasking is waiting a bit so multitasking is not working properly.

I was using 2 RFID, 2 steppers, 2 loadcells and 2 relay modules at the same time. For example, if two tags were read from 2 RFID reader modules, the stepper motors were working at the same time. I am doing this codes with millis() . But now I can't do multitasking, I think the problem is, ethernet library has delay.

I am using khoih-prog/EthernetWebServer library. HTTP client has these lines ;

#define kHttpWaitForDataDelay     1000L // Number of milliseconds that we wait each time there isn't any data
// available to be read (during status code and header processing)

delay(kHttpWaitForDataDelay); // We haven't got any data, so let's pause to allow some to
        // arrive

So is this the problem ?

My simple code structure is (I am trying to use only ethernet and hx711 same time with this code):

#include "defines.h"
#include <ArduinoJson.h>
#include "HX711.h"

const char serverAddress[] = "jsonplaceholder.typicode.com";  // server address
int port = 80;
EthernetClient  client;
EthernetHttpClient  httpClient(client, serverAddress, port);
class httpGetRequest
{
    unsigned long startTime = 0;
    long active_time;
  public:
    httpGetRequest(long active)
    {
      active_time = active;
    }
    void Update()
    {
      unsigned long setCurrentMillis = millis();
      if (setCurrentMillis - startTime >= active_time)
      {
        startTime = setCurrentMillis;
        String get_path = "/todos/1";
        httpClient.get(get_path);
        int statusCode = httpClient.responseStatusCode();
        Serial.println(statusCode);
        String response = httpClient.responseBody();
        Serial.print("Response: ");
        Serial.println(response);
        StaticJsonDocument<200> doc;
        deserializeJson(doc, response);
        int userId = doc["userId"];
        Serial.println(userId);   
      }
    }
};
class hx711
{
    HX711 scale;
    unsigned long startTime = 0;
    long active_time;
    int LOADCELL_DOUT_PIN ;
    int LOADCELL_SCK_PIN ;

  public :
    hx711(long active, int dout_pin, int sck_pin)
    {
      LOADCELL_DOUT_PIN = dout_pin;
      LOADCELL_SCK_PIN = sck_pin;
      active_time = active;
      scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
      scale.set_scale(1280.f);
      scale.tare();
    }
    void Update()
    {
      unsigned long setCurrentMillis = millis();
      if (setCurrentMillis - startTime >= active_time)
      {
        startTime = setCurrentMillis;
        float reading = (scale.get_units(1));
        Serial.println(reading);
      }
    }
};

httpGetRequest http_get_request(250);
hx711 hx_711(250, 14, 15);

void setup()
{
    Serial.begin (4800);
     // start the ethernet connection and the server:
  // Use DHCP dynamic IP and random mac
  uint16_t index = millis() % NUMBER_OF_MAC;
  // Use Static IP
  //Ethernet.begin(mac[index], ip);
  Ethernet.begin(mac[index]);
}

void loop()
{
hx_711.Update();
http_get_request.Update();

}
2

I try to use EthernetWebServer (delay(kHttpWaitForDataDelay)) like this,

unsigned long start_Time = 0;
unsigned long HttpWaitForDelay = millis();
        if(HttpWaitForDelay-start_Time>=200)
        {
            start_Time=HttpWaitForDelay;
        }

So far so good. Is this cause anything ?

3

you're possibly right, this line here

responseStatusCode();

is blocking, you can confirm this by introducing a word

return;

just before it ( this will stop HTTP activity though)

you can fiddle around with that function and make it 'unblocking'

OR you can do something like this

String hostServer = "jsonplaceholder.typicode.com";
int httpPort = 80;

 if ( ! client.connected() ) {
    if ( ! client.connect(hostServer.c_str(), httpPort) ) {
      Serial.println("\nserver connection failed");
      return;
    }
  }

String completePath = "/todos/1";

client.println("GET " + completePath + " HTTP/1.1\r\n" +
                  "Host: " + hostServer+ "\r\n" +
                  "Connection: close\r\n" +
                  "\r\n"
                 );

and then in your main loop you invoke some function that listens for the incoming server response

void  getHttpResponse() {
 if ( client.available() ) {
  String resp = "";
  while (client.available()) {
     resp += char(client.read());
    }
    Serial.println("server response: "+resp);
    client.stop();
  }
}
1 Like
4

Thank you, I will try them.

5

Hi again, I have another problem but I couldn't find it. When there is no internet, I started the code lines if ( ! client.connected() ) { } works after 60 second. Something has timeout like this I guess int begin(uint8_t *mac, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
but I couldn't find. I changed this 60000 to 1000 but nothing change. When I start the code lines without internet connection, code lines wait 60 seconds to start.

6

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