Hi, I have been using Blynk for only a few hours and I keep having this error when I compile:
avrdude: ser_open(): can’t open device “\.\COM3”: Access is denied.
My Arduino is an Uno and is connected through COM3. I want to use Blynk through USB because I don’t have an Ethernet Shield. I have also tried the Arduino Example Blink for an LED and that has the same error.
Please ask me if you need more info.
Thanks!
EDIT:
I FORGOT TO ADD CODE SO HERE IT IS:
/* Comment this out to disable prints and save space */
#define BLYNK_PRINT SwSerial
#include <SoftwareSerial.h>
SoftwareSerial SwSerial(10, 11); // RX, TX
#include <BlynkSimpleStream.h>
#include <DHT.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "d2733e23ceb443d2ac964b1ad7abed56";
#define DHTPIN 2 // What digital pin we're connected to
// Uncomment whatever type you're using!
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21 // DHT 21, AM2301
DHT dht(DHTPIN, DHTTYPE);
BlynkTimer timer;
// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void sendSensor()
{
float h = dht.readHumidity();
float t = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit
if (isnan(h) || isnan(t)) {
SwSerial.println("Failed to read from DHT sensor!");
return;
}
// You can send any value at any time.
// Please don't send more that 10 values per second.
Blynk.virtualWrite(V5, h);
Blynk.virtualWrite(V6, t);
}
void setup()
{
// Debug console
SwSerial.begin(9600);
// Blynk will work through Serial
// Do not read or write this serial manually in your sketch
Serial.begin(9600);
Blynk.begin(Serial, auth);
dht.begin();
// Setup a function to be called every second
timer.setInterval(1000L, sendSensor);
}
void loop()
{
Blynk.run();
timer.run();
}