Non blocking WiFi.begin() & Client.connect()

[tech9492]

Hi all,

Below is the code operating on an Arduino RP2040 Nano Connect. I am facing an issue with WiFi/MQTT reconnection portion of my code. When WiFi and MQTT are connected, the code functions as expected. In the event that one is missing, it obstruct void loop().

I am guessing WiFi.begin() and Client.connect() are both blocking. Is there any workaround I can apply?

Thank you.

#include <SPI.h>
#include <WiFiNINA.h>
#include <ArduinoMqttClient.h>
#include "arduino_secrets.h"

const int PSON = A3;
const int SSR = 8;
const int FAN = 6;

unsigned long ssrTimer = 0;  // SSR timer
unsigned long fanTimer = 0;  // Fan timer

int psState = 0;   // PSON status
int ssState = 0;   // SSR status
int fnState = 0;   // FAN status

//Enter data in secret tab(arduino_secrets.h)
char ssid[] = SECRET_SSID;
char pass[] = SECRET_PASS;

WiFiClient wifiClient;
MqttClient mqttClient(wifiClient);

const char broker[] = "10.0.0.2";
int port = 1883;
const char topic[] = "RP2040Nano/PSon";
const char topic2[] = "RP2040Nano/SSR";
const char topic3[] = "RP2040Nano/FAN";

void setup() {
  pinMode(PSON, INPUT);  // analog pin A3 as input
  pinMode(SSR, OUTPUT);  // digital pin 8 as output
  pinMode(FAN, OUTPUT);  // digital pin 6 as output

  digitalWrite(SSR, LOW);
  digitalWrite(FAN, LOW);

  // Attempt to connect to WiFi network:
  WiFi.begin(ssid, pass);

  mqttClient.setKeepAliveInterval(0);
  // Username and Password for MQTT authentication
  mqttClient.setUsernamePassword(SECRET_MQTT_USER, SECRET_MQTT_PASS);
  mqttClient.connect(broker, port);
}

void loop() {
  psState = analogRead(PSON);  // read analog input status
  ssState = digitalRead(SSR);  // read digital output status
  fnState = digitalRead(FAN);  // read digital output status

  // call poll() regularly to allow the library to send MQTT and prevent disconnection by the broker
  mqttClient.poll();

  if (psState > 50) {
    ssrTimer = 100;  // delay SSR for 10 seconds
  }

  psOFF();

  if (ssState == 1) {
    fanTimer = 100;  // delay Fan for 10 seconds
  }

  fnOFF();

  if (WiFi.status() != WL_CONNECTED) {
    WiFi.end();
    WiFi.begin(ssid, pass);
  }

  if (WiFi.status() == WL_CONNECTED && !mqttClient.connected()) {
    mqttClient.stop();
    mqttClient.connect(broker, port);
  }

  if (WiFi.status() == WL_CONNECTED && mqttClient.connected()) {
    tele();
  }
}

void psOFF() {
  static unsigned long sspreviousTime;
  unsigned long sscurrentTime = millis();  // return time since board active

  // move forward if 100 ms has elapsed
  if (sscurrentTime - sspreviousTime < 100) {
    return;
  }
  
  sspreviousTime = sscurrentTime;

  if (!ssrTimer) {
    digitalWrite(SSR, LOW);  // if timer is done or still 0, set digital output LOW
  } else {
    digitalWrite(SSR, HIGH);  // set digital output HIGH
    digitalWrite(FAN, HIGH);  // set ditigal output HIGH
    ssrTimer--;
  }
}

void fnOFF() {
  static unsigned long fnpreviousTime;
  unsigned long fncurrentTime = millis();  // return time since board active

  // move forward if 100 ms has elapsed
  if (fncurrentTime - fnpreviousTime < 100) {
    return;
  }

  fnpreviousTime = fncurrentTime;

  if (!fanTimer) {
    digitalWrite(FAN, LOW);  // if timer is done or still 0, set digital output LOW
  } else {
    digitalWrite(FAN, HIGH);  // set digital output HIGH
    fanTimer--;
  }
}

void tele() {
  static unsigned long previousMillis;
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= 10000) {
 
    previousMillis = currentMillis;

    // send message, the Print interface can be used to set the message contents
    mqttClient.beginMessage(topic);
    mqttClient.print(psState);
    mqttClient.endMessage();

    mqttClient.beginMessage(topic2);
    mqttClient.print(ssState);
    mqttClient.endMessage();

    mqttClient.beginMessage(topic3);
    mqttClient.print(fnState);
    mqttClient.endMessage();

    mqttClient.beginMessage(topic4);
    mqttClient.print(temp_deg);
    mqttClient.endMessage();
  }
}

[JAndrassy]

#252

[tech9492]

@JAndrassy thank you very much for your quick response. I did come across #252 but was not sure if that was the solution.

Regarding WiFi.begin(), would WiFi.setTimeout() be the solution?

Thank you.

[JAndrassy]

Regarding WiFi.begin(), would WiFi.setTimeout() be the solution?

what can your sketch do without WiFi connected to AP?

as first remove the useless wait time in WiFiClient.connect. this

while (!connected() && millis() - start < 10000)
    		delay(1);

it jus wastes 10 seconds if the connection ended with timeout in firmware

[tech9492]

what can your sketch do without WiFi connected to AP?

It reads the value of input pin A3 and controls 2 pins(output). When pin A3 is LOW, it will activate a timer to switch outputs LOW. This portion of the code should be able to execute even without WiFi.

[JAndrassy]

you can do 3 things with WiFi.begin:

1. don't try to connect every loop
2. run wifi scan before attempting to connect

maybe you can control the pins with MCU events/timers/interrupts so that they are independent from loop

[tech9492]

you can do 3 things with WiFi.begin:

1. don't try to connect every loop
2. run wifi scan before attempting to connect

Thank you for the suggestions. Wifi scan before connecting seem to be a good workaround.

Regarding Client.connect(), I applied all the required changes from #252 to my WiFiNINA library. I tried a timeout of 1000(1 second), it does not solve the issue.

Thank you.

[JAndrassy]

applied all the required changes from #252 to my WiFiNINA library

the firmware too?

[tech9492]

By firmware, do you mean server_drv.h?

I have modified the 4 files listed in #252. Did I miss something?

[JAndrassy]

there are changes in the nina-fw for the NINA Esp32 module as linked in the description of the PR

[tech9492]

there are changes in the nina-fw for the NINA Esp32 module as linked in the description of the PR

Just to confirm, is it Client connect timeout support #89?

[JAndrassy]

Just to confirm, is it arduino/nina-fw#89?

yes that is the PR for the firmware

[tech9492]

I am a little lost now.

Where are firmware files located? Could you please guide me how to carry out this procedure.

Thank you.

[JAndrassy]

Where are firmware files located?

in the repository with the PR of course

https://github.com/arduino/nina-fw/blob/master/README.md

[sebdehne]

I have the same issue (WiFi.begin()) being a blocking function. I have made some slight modification to WiFiNINA locally:

1. expose WiFiDrv::wifiSetPassphrase() publicly
2. added begin() which does exactly what begin(const char* ssid, const char *passphrase) does, but without the loop. It just callsWiFiDrv::getConnectionStatus() and returns the status.

This should make it possible to (re-)connect in a non-blocking way.

Would it be possible to have this available in a public release?

[JAndrassy]

@sebdehne did you read the comments above?