Here is an working example of working MQTT connection that you can use as a model for your own code or not:
#include <WiFi.h>
#include <PubSubClient.h>
#include "certs.h" // include the connection infor for WiFi and MQTT
#include "sdkconfig.h" // used for log printing
#include "esp_system.h"
#include "freertos/FreeRTOS.h" //freeRTOS items to be used
#include "freertos/task.h"
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include "Adafruit_BME680.h"
#include <Adafruit_GFX.h> // Core graphics library
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789
#include <driver/adc.h>
#include "esp32-hal-ledc.h"
//#include "LinearRegression.h"
////
Adafruit_BME680 bme( GPIO_NUM_5 ); // use hardware SPI, set GPIO pin to use
//Adafruit_ST7789 tft = Adafruit_ST7789( TFT_CS , TFT_DC , TFT_MOSI , TFT_SCLK , TFT_RST );
Adafruit_ST7789 tft = Adafruit_ST7789( GPIO_NUM_15, GPIO_NUM_0, GPIO_NUM_13, GPIO_NUM_14, GPIO_NUM_22 );
WiFiClient wifiClient; // do the WiFi instantiation thing
PubSubClient MQTTclient( mqtt_server, mqtt_port, wifiClient ); //do the MQTT instantiation thing
LinearRegression lr;
//////
#define evtDoParticleRead ( 1 << 0 ) // declare an event
#define evtWaitForBME ( 1 << 1 )
#define evtParseMQTT ( 1 << 3 )
EventGroupHandle_t eg; // variable for the event group handle
//////
QueueHandle_t xQ_eData; // environmental data to be displayed on the screen
QueueHandle_t xQ_lrData; // linear regression data
struct stu_eData
{
float Temperature = 0.0f;
float Pressure = 0.0f;
float Humidity = 0.0f;
float IAQ = 0.0f;
float RM0 = 0.0f;
float PM2 = 0.0f;
} x_eData; // environmental data
QueueHandle_t xQ_Message; // payload and topic queue of MQTT payload and topic
const int payloadSize = 100;
struct stu_message
{
char payload [payloadSize] = {'\0'};
String topic ;
} x_message;
////
QueueHandle_t xQ_pMessage;
////
const float oGasResistanceBaseLine = 149598.0f;
int mqttOK = 0;
//////
esp_timer_handle_t oneshot_timer; //veriable to store the hardware timer handle
//////
SemaphoreHandle_t sema_MQTT_KeepAlive;
SemaphoreHandle_t sema_PublishPM;
SemaphoreHandle_t sema_mqttOK;
//////
// interrupt service routine for WiFi events put into IRAM
void IRAM_ATTR WiFiEvent(WiFiEvent_t event)
{
switch (event) {
case SYSTEM_EVENT_STA_CONNECTED:
log_i("Connected to WiFi access point");
break;
case SYSTEM_EVENT_STA_DISCONNECTED:
log_i("Disconnected from WiFi access point");
break;
case SYSTEM_EVENT_AP_STADISCONNECTED:
log_i("WiFi client disconnected");
break;
default: break;
}
} // void IRAM_ATTR WiFiEvent(WiFiEvent_t event)
//////
void IRAM_ATTR oneshot_timer_callback( void* arg )
{
BaseType_t xHigherPriorityTaskWoken;
xEventGroupSetBitsFromISR( eg, evtDoParticleRead, &xHigherPriorityTaskWoken ); //freeRTOS event trigger made for ISR's
} //void IRAM_ATTR oneshot_timer_callback( void* arg )
//////
void IRAM_ATTR mqttCallback(char* topic, byte * payload, unsigned int length)
{
memset( x_message.payload, '\0', payloadSize ); // clear payload char buffer
x_message.topic = ""; //clear topic string buffer
x_message.topic = topic; //store new topic
int i = 0; // extract payload
for ( i; i < length; i++)
{
x_message.payload[i] = ((char)payload[i]);
}
x_message.payload[i] = '\0';
xQueueOverwrite( xQ_Message, (void *) &x_message );// send data to queue
} // void mqttCallback(char* topic, byte* payload, unsigned int length)
////
void setup()
{
x_message.topic.reserve( payloadSize );
//
xQ_Message = xQueueCreate( 1, sizeof(stu_message) );
xQ_eData = xQueueCreate( 1, sizeof(stu_eData) ); // sends a queue copy of the structure
xQ_lrData = xQueueCreate( 1, sizeof(float) );
//String x = "";
//x.reserve(500);
//xQ_pMessage = xQueueCreate( 1, sizeof(x) ); //set size of string queue to a string of 500 string characters.
//
sema_PublishPM = xSemaphoreCreateBinary();
xSemaphoreGive( sema_PublishPM );
sema_mqttOK = xSemaphoreCreateBinary();
xSemaphoreGive( sema_mqttOK );
ledcSetup( 4, 12000, 8 ); // ledc: 4 => Group: 0, Channel: 2, Timer: 1, led frequency, resolution bits // blue led
ledcAttachPin( GPIO_NUM_12, 4 ); // gpio number and channel
ledcWrite( 4, 0 ); // write to channel number 4
//
eg = xEventGroupCreate(); // get an event group handle
//
gpio_config_t io_cfg = {}; // initialize the gpio configuration structure
io_cfg.mode = GPIO_MODE_OUTPUT; // set gpio mode
io_cfg.pin_bit_mask = ( (1ULL << GPIO_NUM_4) ); //bit mask of the pins to set
gpio_config(&io_cfg); // configure the gpio based upon the parameters as set in the configuration structure
gpio_set_level( GPIO_NUM_4, LOW); // set air particle sensor trigger pin to LOW
// set up A:D channels, refer: https://dl.espressif.com/doc/esp-idf/latest/api-reference/peripherals/adc.html
adc1_config_width(ADC_WIDTH_12Bit);
adc1_config_channel_atten(ADC1_CHANNEL_0, ADC_ATTEN_DB_11);// using GPIO 36
// https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/esp_timer.html?highlight=hardware%20timer High Resoultion Timer API
esp_timer_create_args_t oneshot_timer_args = {}; // initialize High Resoulition Timer (HRT) configuration structure
oneshot_timer_args.callback = &oneshot_timer_callback; // configure for callback, name of callback function
esp_timer_create( &oneshot_timer_args, &oneshot_timer ); // assign configuration to the HRT, receive timer handle
//
xTaskCreatePinnedToCore( fparseMQTT, "fparseMQTT", 7000, NULL, 5, NULL, 1 );
xTaskCreatePinnedToCore( MQTTkeepalive, "MQTTkeepalive", 15000, NULL, 6, NULL, 1 );
xTaskCreatePinnedToCore( DoTheBME680Thing, "DoTheBME280Thing", 20000, NULL, 5, NULL, 1);
xTaskCreatePinnedToCore( fDoParticleDetector, "fDoParticleDetector", 6000, NULL, 3, NULL, 1 );
xTaskCreatePinnedToCore( fmqttWatchDog, "fmqttWatchDog", 3000, NULL, 3, NULL, 1 );
xTaskCreatePinnedToCore( fDoTheDisplayThing, "fDoTheDisplayThing", 22000, NULL, 3, NULL, 1 );
xTaskCreatePinnedToCore( fDoTrends, "fDoTrends", 5000, NULL, 3, NULL, 1 );
//xTaskCreatePinnedToCore( fSendMQTTpressure, "fSendMQTTpressure", 3000, NULL, 3, NULL, 1 );
} //void setup()
////
//void fSendMQTTpressure( void *pvParameters )
//{
// //struct stu_pressureMessage px_message;
// String apInfo = "";
// apInfo.reserve( 150 );
// for ( ;; )
// {
// if ( xQueueReceive(xQ_pMessage, &apInfo, portMAX_DELAY) == pdTRUE )
// {
// if ( MQTTclient.connected() )
// {
// xSemaphoreTake( sema_MQTT_KeepAlive, portMAX_DELAY );
// MQTTclient.publish( topicPressureInfo, apInfo.c_str() );
// vTaskDelay( 1 );
// xSemaphoreGive( sema_MQTT_KeepAlive );
// } else {
// log_i( "fSendMQTTpressure not connected" );
// }
// apInfo = "";
// }
// } // for ( ;; )
// vTaskDelete( NULL );
//} //void fSendMQTTpresure( void *pvParameters )
//////
void fparseMQTT( void *pvParameters )
{
struct stu_message px_message;
for (;;)
{
if ( xQueueReceive(xQ_Message, &px_message, portMAX_DELAY) == pdTRUE )
{
xSemaphoreTake( sema_mqttOK, portMAX_DELAY );
mqttOK = 0;
xSemaphoreGive( sema_mqttOK );
if ( px_message.topic == topicRemainingMoisture_0 )
{
x_eData.RM0 = String(px_message.payload).toFloat();
}
} //if ( xQueueReceive(xQ_Message, &px_message, portMAX_DELAY) == pdTRUE )
} //for(;;)
vTaskDelete( NULL );
} // void fparseMQTT( void *pvParameters )
////
void fDoTheDisplayThing( void * parameter )
{
tft.init( 240, 320 ); // Init ST7789 320x240
tft.setRotation( 3 );
tft.setTextSize( 3 );
tft.fillScreen( ST77XX_BLACK );
tft.setTextWrap( false );
struct stu_eData px_eData;
int OneTwoThree = 0;
int countUpDown = 255;
ledcWrite( 4, countUpDown ); //backlight set
int dimDelaytime = 7;
for (;;)
{
if ( xQueueReceive(xQ_eData, &px_eData, portMAX_DELAY) == pdTRUE )
{
for ( countUpDown; countUpDown-- > 0; )
{
ledcWrite( 4, countUpDown ); // write to channel number 4, dim backlight
vTaskDelay( dimDelaytime );
}
tft.fillScreen(ST77XX_BLACK);
tft.setCursor( 0, 0 );
OneTwoThree++;
if ( OneTwoThree == 1 )
{
tft.setTextColor( ST77XX_RED );
}
if ( OneTwoThree == 2 )
{
tft.setTextColor( ST77XX_WHITE );
}
if ( OneTwoThree == 3 )
{
tft.setTextColor( ST77XX_BLUE );
OneTwoThree = 0;
}
tft.println( "Temp " + String(px_eData.Temperature) + "F" );
tft.setCursor( 0, 30 );
tft.println( "Hum " + String(px_eData.Humidity) + "%" );
tft.setCursor( 0, 60 );
tft.println( "Pres " + String(px_eData.Pressure) + "mmHg" );
tft.setCursor( 0, 90 );
tft.println( "AQI " + String(px_eData.IAQ) + "%" );
tft.setCursor( 0, 120 );
tft.println( "RM0 " + String(px_eData.RM0) + "%" );
tft.setCursor( 0, 150 );
tft.println( "PM2 " + String(px_eData.PM2) + "ug/m3" );
tft.setCursor( 0, 180 );
if ( px_eData.PM2 <= 35.0f )
{
//tft.setTextColor( ST77XX_GREEN );
tft.println( "PM2 is Excellent" );
}
if ( (px_eData.PM2 > 35.0f) && px_eData.PM2 <= 75.0f )
{
tft.println( "PM2 is Average" );
}
if ( (px_eData.PM2 > 75.0f) && px_eData.PM2 <= 115.0f )
{
tft.println( "PM2 is Light" );
}
if ( (px_eData.PM2 > 115.0f) && px_eData.PM2 <= 150.0f )
{
tft.println( "PM2 is Moderate" );
}
if ( (px_eData.PM2 > 150.0f) && px_eData.PM2 <= 250.0f )
{
tft.println( "PM2 is Heavy" );
}
if ( (px_eData.PM2 > 250.0f) )
{
tft.println( "PM2 is Serious" );
}
//brighten blacklight level
vTaskDelay( 400 ); // wait for screen update to be done
for ( countUpDown; countUpDown <= 255; countUpDown++ )
{
ledcWrite( 4, countUpDown ); // write to channel number 4
vTaskDelay( dimDelaytime );
}
//log_i( "DoTheBME280Thing high watermark % d", uxTaskGetStackHighWaterMark( NULL ) );
} //if ( xQueueReceive(xQ_eData, &px_eData, portMAX_DELAY) == pdTRUE )
} //for (;;)
vTaskDelete( NULL );
} //void fDoTheDisplayTHing( void * parameter )
////
void fmqttWatchDog( void * paramater )
{
int maxNonMQTTresponse = 5;
for (;;)
{
vTaskDelay( 1000 );
if ( mqttOK >= maxNonMQTTresponse )
{
ESP.restart();
}
}
vTaskDelete( NULL );
}
////
float fCalulate_IAQ_Index( int gasResistance, float Humidity)
{
float hum_baseline = 40.0f;
float hum_weighting = 0.25f;
float gas_offset = 0.0f;
float hum_offset = 0.0f;
float hum_score = 0.0f;
float gas_score = 0.0f;
gas_offset = oGasResistanceBaseLine - float( gasResistance );
hum_offset = float( Humidity ) - hum_baseline;
// calculate hum_score as distance from hum_baseline
if ( hum_offset > 0.0f )
{
hum_score = 100.0f - hum_baseline - hum_offset;
hum_score /= ( 100.0f - hum_baseline );
hum_score *= ( hum_weighting * 100.0f );
} else {
hum_score = hum_baseline + hum_offset;
hum_score /= hum_baseline;
hum_score *= ( 100.0f - (hum_weighting * 100.0f) );
}
//calculate gas score as distance from baseline
if ( gas_offset > 0.0f )
{
gas_score = float( gasResistance ) / oGasResistanceBaseLine;
gas_score *= ( 100.0f - (hum_weighting * 100.0f ) );
} else {
gas_score = 100.0f - ( hum_weighting * 100.0f );
}
return ( hum_score + gas_score );
} //void fCalulate_IAQ_Index( int gasResistance, float Humidity):
////
void fDoParticleDetector( void * parameter )
{
/*
ug/m3 AQI Lvl AQ (Air Quality)
(air Quality Index)
0-35 0-50 1 Excellent
35-75 51-100 2 Average
75-115 101-150 3 Light pollution
115-150 151-200 4 moderate
150-250 201-300 5 heavy
250-500 >=300 6 serious
*/
float ADbits = 4095.0f;
float uPvolts = 3.3f;
float adcValue = 0.0f;
float dustDensity = 0.0f;
float Voc = 0.6f; // Set the typical output voltage in Volts when there is zero dust.
const float K = 0.5f; // Use the typical sensitivity in units of V per 100ug/m3.
xEventGroupWaitBits (eg, evtWaitForBME, pdTRUE, pdTRUE, portMAX_DELAY );
TickType_t xLastWakeTime = xTaskGetTickCount();
const TickType_t xFrequency = 100; //delay for mS
for (;;)
{
//enable sensor led
gpio_set_level( GPIO_NUM_4, HIGH ); // set gpio 4 to high to turn on sensor internal led for measurement
esp_timer_start_once( oneshot_timer, 280 ); // trigger one shot timer for a 280uS timeout, warm up time.
xEventGroupWaitBits (eg, evtDoParticleRead, pdTRUE, pdTRUE, portMAX_DELAY ); // event will be triggered by the timer expiring, wait here for the 280uS
adcValue = float( adc1_get_raw(ADC1_CHANNEL_0) ); //take a raw ADC reading from the dust sensor
gpio_set_level( GPIO_NUM_4, LOW );//Shut off the sensor LED
adcValue = ( adcValue * uPvolts ) / ADbits; //calculate voltage
dustDensity = (adcValue / K) * 100.0; //convert volts to dust density
if ( dustDensity < 0.0f )
{
dustDensity = 0.00f; // make negative values a 0
}
if ( xSemaphoreTake( sema_PublishPM, 0 ) == pdTRUE ) // don't wait for semaphore to be available
{
xSemaphoreTake( sema_MQTT_KeepAlive, portMAX_DELAY );
//log_i( "ADC volts %f Dust Density = %ug / m3 ", adcValue, dustDensity ); // print the calculated voltage and dustdensity
MQTTclient.publish( topicInsidePM, String(dustDensity).c_str() );
xSemaphoreGive( sema_MQTT_KeepAlive );
x_eData.PM2 = dustDensity;
}
xLastWakeTime = xTaskGetTickCount();
vTaskDelayUntil( &xLastWakeTime, xFrequency );
//log_i( " high watermark % d", uxTaskGetStackHighWaterMark( NULL ) );
}
vTaskDelete( NULL );
}// end fDoParticleDetector()
//// just pass the info the RPi instead of processing here
void fDoTrends( void *pvParameters )
{
// const int magicNumber = 96;
// double values[2];
// int lrCount = 0;
float lrData = 0.0f;
// float DataPoints[magicNumber] = {0.0f};
// float TimeStamps[magicNumber] = {0.0f};
// float dpHigh = 702.0f;
// float dpLow = 683.0f;
// float dpAtom = 0.0f;
// float dpMean = 0.0f; //data point mean
// float tsAtom = 0.0f;
// float tsUnit = 0.0f;
// float tsMean = 0.0f;
// bool dpRecalculate = true;
// bool FirstTimeMQTT = true;
String apInfo = "";
apInfo.reserve( 150 );
for (;;)
{
if ( xQueueReceive(xQ_lrData, &lrData, portMAX_DELAY) == pdTRUE )
{
apInfo.concat( String((float)xTaskGetTickCount() / 1000.0f) );
apInfo.concat( "," );
apInfo.concat( String(lrData) );
apInfo.concat( ",0.0" );
apInfo.concat( ",0.0" );
if ( MQTTclient.connected() )
{
xSemaphoreTake( sema_MQTT_KeepAlive, portMAX_DELAY );
MQTTclient.publish( topicPressureInfo, apInfo.c_str() );
vTaskDelay( 1 );
xSemaphoreGive( sema_MQTT_KeepAlive );
}
//xQueueSend( xQ_pMessage, (void *) &apInfo, portMAX_DELAY ); // wait for queue space to become available
apInfo = "";
//find dpHigh and dpLow, collects historical high and low data points, used for data normalization
// if ( lrData > dpHigh )
// {
// dpHigh = lrData;
// dpRecalculate = true;
// }
// if ( lrData < dpLow )
// {
// dpLow = lrData;
// dpRecalculate = true;
// }
// if ( lrCount != magicNumber )
// {
// DataPoints[lrCount] = lrData;
// TimeStamps[lrCount] = (float)xTaskGetTickCount() / 1000.0f;
// log_i( "lrCount %d TimeStamp %f lrData %f", lrCount, TimeStamps[lrCount], DataPoints[lrCount] );
// lrCount++;
// } else {
// //shift datapoints collected one place to the left
// for ( int i = 0; i < magicNumber; i++ )
// {
// DataPoints[i] = DataPoints[i + 1];
// TimeStamps[i] = TimeStamps[i + 1];
// }
// //insert new data points and time stamp (ts) at the end of the data arrays
// DataPoints[magicNumber - 1] = lrData;
// TimeStamps[magicNumber - 1] = (float)xTaskGetTickCount() / 1000.0f;
// lr.Reset(); //reset the LinearRegression Parameters
// // use dpHigh and dpLow to calculate data mean atom for normalization
// if ( dpRecalculate )
// {
// dpAtom = 1.0f / (dpHigh - dpLow); // a new high or low data point has been found adjust mean dpAtom
// dpRecalculate = false;
// }
// //timestamp mean is ts * (1 / ts_Firstcell - ts_Lastcell[magicNumber]). ts=time stamp
// tsAtom = 1.0f / (TimeStamps[magicNumber - 1] - TimeStamps[0]); // no need to do this part of the calculation every for loop ++
// for (int i = 0; i < magicNumber; i++)
// {
// dpMean = (DataPoints[i] - dpLow) * dpAtom;
// tsMean = TimeStamps[i] * tsAtom;
// lr.Data( tsMean, dpMean ); // train lr
// //send to mqtt the first time
// if ( FirstTimeMQTT )
// {
// apInfo.concat( String(TimeStamps[i]) );
// apInfo.concat( "," );
// apInfo.concat( String(DataPoints[i]) );
// apInfo.concat( "," );
// apInfo.concat( String(tsMean) );
// apInfo.concat( "," );
// apInfo.concat( String(dpMean) );
// xQueueSend( xQ_pMessage, (void *) &apInfo, portMAX_DELAY ); // wait for queue space to become available
// apInfo = "";
// }
// }
// if ( !FirstTimeMQTT )
// {
// apInfo.concat( String(TimeStamps[magicNumber - 1]) );
// apInfo.concat( "," );
// apInfo.concat( String(DataPoints[magicNumber - 1]) );
// apInfo.concat( "," );
// apInfo.concat( String(tsMean) );
// apInfo.concat( "," );
// apInfo.concat( String(dpMean) );
// xQueueSend( xQ_pMessage, (void *) &apInfo, portMAX_DELAY );
// apInfo = "";
// }
// FirstTimeMQTT = false;
// lr.Parameters( values );
// //calculate
// tsUnit = TimeStamps[magicNumber - 1] - TimeStamps[magicNumber - 2]; //get the time stamp quantity
// tsUnit += TimeStamps[magicNumber - 1]; //get a future time
// tsUnit *= tsAtom; //setting time units to the same scale
// log_i( "Calculate next x using y = %f", lr. Calculate( tsUnit ) ); //calculate next datapoint using time stamp
// log_i( "Correlation: %f Values: Y=%f and *X + %f ", lr.Correlation(), values[0], values[1] ); // correlation is the strength and direction of the relationship
// //calculate datapoint for current time stamp, use current data point against calculated datapoint to get error magnatude and direction.
// //log_i( "lr.Error( x_pMessage.TimeStamp, x_pMessage.nDataPoint ) %f", lr.Error(x_pMessage.nTimeStamp, x_pMessage.nDataPoint) ); //
// }
//log_i( "fDoTrends high watermark % d", uxTaskGetStackHighWaterMark( NULL ) );
} //if ( xQueueReceive(xQ_lrData, &lrData, portMAX_DELAY) == pdTRUE )
} //for(;;)
vTaskDelete ( NULL );
} //void fDoTrends( void *pvParameters )
////
void DoTheBME680Thing( void *pvParameters )
{
SPI.begin(); // initialize the SPI library
vTaskDelay( 10 );
if (!bme.begin()) {
log_i("Could not find a valid BME680 sensor, check wiring!");
while (1);
}
// Set up oversampling and filter initialization
bme.setTemperatureOversampling(BME680_OS_8X);
bme.setHumidityOversampling(BME680_OS_2X);
bme.setPressureOversampling(BME680_OS_4X);
bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
bme.setGasHeater(320, 150); // 320*C for 150 ms
//wait for a mqtt connection
while ( !MQTTclient.connected() )
{
vTaskDelay( 250 );
}
xEventGroupSetBits( eg, evtWaitForBME );
TickType_t xLastWakeTime = xTaskGetTickCount();
const TickType_t xFrequency = 1000 * 15; //delay for mS
int sendLRDataTrigger = 240; // 1 hour-ish = 240
int sendLRdataCount = sendLRDataTrigger - 1; //send linear regression data when count is reached
String bmeInfo = "";
bmeInfo.reserve( 100 );
for (;;)
{
x_eData.Temperature = bme.readTemperature();
x_eData.Temperature = ( x_eData.Temperature * 1.8f ) + 32.0f; // (Celsius x 1.8) + 32
x_eData.Pressure = bme.readPressure();
x_eData.Pressure = x_eData.Pressure / 133.3223684f; //converts to mmHg
sendLRdataCount++;
if ( sendLRdataCount >= sendLRDataTrigger )
{
xQueueOverwrite( xQ_lrData, (void *) &x_eData.Pressure ); // send to trends
sendLRdataCount = 0;
}
x_eData.Humidity = bme.readHumidity();
x_eData.IAQ = fCalulate_IAQ_Index( bme.readGas(), x_eData.Humidity );
//log_i( " temperature % f, Pressure % f, Humidity % f IAQ % f", x_eData.Temperature, x_eData.Pressure, x_eData.Humidity, x_eData.IAQ);
bmeInfo.concat( String(x_eData.Temperature, 2) );
bmeInfo.concat( "," );
bmeInfo.concat( String(x_eData.Pressure, 2) );
bmeInfo.concat( "," );
bmeInfo.concat( String(x_eData.Humidity, 2) );
bmeInfo.concat( "," );
bmeInfo.concat( String(x_eData.IAQ, 2) );
xSemaphoreTake( sema_MQTT_KeepAlive, portMAX_DELAY );
if ( MQTTclient.connected() )
{
MQTTclient.publish( topicInsideInfo, bmeInfo.c_str() );
}
xSemaphoreGive( sema_MQTT_KeepAlive );
xSemaphoreGive( sema_PublishPM ); // release publish of dust density
xSemaphoreTake( sema_mqttOK, portMAX_DELAY );
mqttOK ++;
xSemaphoreGive( sema_mqttOK );
xQueueOverwrite( xQ_eData, (void *) &x_eData );// send data to display
//
bmeInfo = ""; // empty string
xLastWakeTime = xTaskGetTickCount();
vTaskDelayUntil( &xLastWakeTime, xFrequency );
// log_i( "DoTheBME280Thing high watermark % d", uxTaskGetStackHighWaterMark( NULL ) );
}
vTaskDelete ( NULL );
}
////
/*
Important to not set vTaskDelay/vTaskDelayUntil to less then 10. Errors begin to develop with the MQTT and network connection.
makes the initial wifi/mqtt connection and works to keeps those connections open.
*/
void MQTTkeepalive( void *pvParameters )
{
sema_MQTT_KeepAlive = xSemaphoreCreateBinary();
xSemaphoreGive( sema_MQTT_KeepAlive ); // found keep alive can mess with a publish, stop keep alive during publish
MQTTclient.setKeepAlive( 90 ); // setting keep alive to 90 seconds makes for a very reliable connection, must be set before the 1st connection is made.
TickType_t xLastWakeTime = xTaskGetTickCount();
const TickType_t xFrequency = 250; //delay for ms
for (;;)
{
//check for a is-connected and if the WiFi 'thinks' its connected, found checking on both is more realible than just a single check
if ( (wifiClient.connected()) && (WiFi.status() == WL_CONNECTED) )
{
xSemaphoreTake( sema_MQTT_KeepAlive, portMAX_DELAY ); // whiles MQTTlient.loop() is running no other mqtt operations should be in process
MQTTclient.loop();
xSemaphoreGive( sema_MQTT_KeepAlive );
}
else {
log_i( "MQTT keep alive found MQTT status % s WiFi status % s", String(wifiClient.connected()), String(WiFi.status()) );
if ( !(wifiClient.connected()) || !(WiFi.status() == WL_CONNECTED) )
{
connectToWiFi();
}
connectToMQTT();
}
xLastWakeTime = xTaskGetTickCount();
vTaskDelayUntil( &xLastWakeTime, xFrequency );
}
vTaskDelete ( NULL );
}
////
void connectToMQTT()
{
byte mac[5]; // create client ID from mac address
WiFi.macAddress(mac); // get mac address
String clientID = String(mac[0]) + String(mac[4]) ; // use mac address to create clientID
while ( !MQTTclient.connected() )
{
MQTTclient.connect( clientID.c_str(), mqtt_username, mqtt_password );
//log_i( "connecting to MQTT" );
vTaskDelay( 250 );
}
MQTTclient.setCallback( mqttCallback );
MQTTclient.subscribe( topicOK );
MQTTclient.subscribe( topicRemainingMoisture_0 );
//log_i("MQTT Connected");
} //void connectToMQTT()
void connectToWiFi()
{
int TryCount = 0;
//log_i( "connect to wifi" );
while ( WiFi.status() != WL_CONNECTED )
{
TryCount++;
WiFi.disconnect();
WiFi.begin( SSID, PASSWORD );
//log_i(" waiting on wifi connection" );
vTaskDelay( 4000 );
if ( TryCount == 10 )
{
ESP.restart();
}
}
//log_i( "Connected to WiFi" );
WiFi.onEvent( WiFiEvent );
}
////
void loop() { }
It's written for an ESP32.