Hi all,
I recently connected my ESP32 dev board to the Blynk IoT using Edgent library. The ESP32 controls a relay (which turns ON/OFF an LED strip) and also have a physical switch. There is also a temp sensor on Onewire. All of these components are inside an ABS IP67 enclosure. The enclosure is just outside of my house, where the wifi strength is still pretty good (so I think). Ever since deploying the device, I get many notifications that the device went offline - about every 15 min or so. When I check in Blynk, it seems that it is back online right away, so it doesn’t seem like it was offline for long. I have several other ESP32 based devices around my house and none of them are going offline so frequently. Why is this happening so much and how can I fix it?
I’m using latest Blynk library 1.2.0. Below is my sketch in case the issue is coming from poor coding (which I do sometimes 
).
Finally note that I have probably done something incorrect… I added a loop that gets entered only once at first run to initialize some of the virtual signals. I find that I cannot seem to get the initial values set properly, so I attempted to make this loop, controlled by flag_initial… Any comments on that would be appreciated also. Maybe there is a better way?
Cheers,
MathPi
#define BLYNK_TEMPLATE_ID "REMVOED"
#define BLYNK_TEMPLATE_NAME "REMOVED"
#define BLYNK_FIRMWARE_VERSION "0.0.1"
#define BLYNK_PRINT Serial
#define APP_DEBUG
//#define USE_ESP32_DEV_MODULE
#include "BlynkEdgent.h"
#include <OneWire.h>
#include <DallasTemperature.h>
#define pin_switch 27 // Pin at which the switch is attached
#define pin_relay 32 // Pin which controls relay
#define ONE_WIRE_BUS 2 // Pin at which the temp data is passed
BlynkTimer timer; // Announcing the timer
// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
// Addresses of DS18B20
uint8_t sensor1[8] = {0x28, 0x0B, 0xE4, 0x07, 0xD6, 0x01, 0x3C, 0xB4};
int LED_status;
int LED_status_previous;
int buttonState;
int buttonState_previous;
int virtualLEDButton;
unsigned long ON_timer;
double ON_timer_hrs;
int flag = 0;
int flag_initial = 0;
BLYNK_WRITE(V4) {
// integer value for virtual LED ON/OFF button
virtualLEDButton = param.asInt();
}
BLYNK_WRITE(V5) {
// user-set off-timer value
ON_timer_hrs = param.asDouble() * 60.0 * 60.0 * 1000.0;
}
void setup() {
sensors.begin();
BlynkEdgent.begin();
pinMode(pin_relay, OUTPUT);
pinMode(pin_switch, INPUT_PULLUP);
Serial.begin(9600);
Blynk.virtualWrite(V3, 0); // Set LEDs initially to off
Blynk.virtualWrite(V4, 0); // Set virtual button state initially to off
Blynk.virtualWrite(V5, 2); // Set On time in hrs default
timer.setInterval(5L, data_transfer);
}
void loop() {
BlynkEdgent.run();
timer.run();
// Initialize
if (flag_initial == 0) {
flag = 0;
flag_initial = 1;
Blynk.virtualWrite(V3, 0); // Set LEDs initially to off
Blynk.virtualWrite(V4, 0); // Set virtual button state initially to off
Blynk.virtualWrite(V5, 2); // Set On time in hrs default
}
}
void data_transfer(){
// Read button state
buttonState = digitalRead(pin_switch);
// Timer logic first, then, If either physical or virtual button state has changed, flip flop LED_status
if (((millis() - ON_timer) >= ON_timer_hrs)&&(flag == 1)) {
flag = 0; // reset timer triger flag
LED_status = 0;
LED_status_previous = LED_status;
virtualLEDButton = LED_status;
Blynk.virtualWrite(V4, LED_status); // Need to update the virtual button
} else if (buttonState != buttonState_previous) {
if (LED_status_previous == 0) {
LED_status = 1;
} else if (LED_status_previous == 1) {
LED_status = 0;
flag = 0;
}
Blynk.virtualWrite(V4, LED_status); // Need to update the virtual button
virtualLEDButton = LED_status;
} else if (virtualLEDButton == 1) {
LED_status = 1;
} else if (virtualLEDButton == 0) {
LED_status = 0;
flag = 0;
}
// Timer to turn off LED. If previously off and then on
if ((LED_status == 1)&&(flag == 0)) {
ON_timer = millis();
flag = 1;
}
// Update how much time is left on the timer, if ON
if (flag == 1) {
Blynk.virtualWrite(V6, (ON_timer_hrs - millis() + ON_timer) / (1000.0 * 60.0 * 60.0)); // Upload how much time is left
} else {
Blynk.virtualWrite(V6, 0); // Upload how much time is left
}
// Update the relay
digitalWrite(pin_relay, LED_status);
// Update state to cloud
Blynk.virtualWrite(V3, LED_status);
// Blynk.virtualWrite(V4, LED_status);
// Temp in C
sensors.requestTemperatures();
printTemperature(sensor1);
// Save to previous states
LED_status_previous = LED_status;
buttonState_previous = buttonState;
}
void printTemperature(DeviceAddress deviceAddress){
float tempC = sensors.getTempC(deviceAddress);
Blynk.virtualWrite(V0, tempC);
Serial.print("Temp: ");
Serial.print(tempC);
Serial.println(" C");
}
