If you experience connection problems, follow these steps:
- Check that your hardware, wires, cables and power supply are good quality, not harmed or damaged, etc.
Use high power USB cables and USB ports. - Check your wiring using the examples (TCP/HTTP Client or similar) provided with your shield and hardware.
- Once you understand how to manage connection, it's much easier to use Blynk.
- Try running command
telnet blynk-cloud.com 80
from your PC, connected to the same network as your hardware. You should see something like:Connected to blynk-cloud.com.
. - Try running Blynk default examples for your platform without modifications to see if it is working.
- Double-check that you have selected the right example for your connection type and hardware model.
- Our examples come with comments and explanations. Read them carefully.
- Check that your Auth Token is valid (copied from the App and doesn't contain spaces, etc.)
- If it doesn't work, try looking into serial debug prints.
- Done! Add your modifications and functionality. Enjoy Blynk!
Note: when you have multiple devices connected to your network, they should all have different MAC and IP addresses. For example, when using 2 Arduino UNO with Ethernet shields, flashing default example to both of them will cause connection problems. You should use manual ethernet configuration example.
If you encounter WiFi connection problems, please check these pitfalls:
- You're trying to connect to "WPA & WPA2 Enterprise" network (often used in offices), and your shield does not support this security method
- Your WiFi network has a login page that requests entering an access token (often used in restaurants)
- Your WiFi network security disallows connecting alien devices completely (MAC filtering, etc)
- There is a firewall running. Default port for hardware connections is 80 (8080 on the Local Server). Make sure it's open.
If you use long delay()
or send your hardware to sleep inside of the loop()
expect connection drops and downgraded performance.
DON'T DO THAT:
void loop()
{
...
delay(1000); // this is long delay, that should be avoided
other_long_operation();
...
Blynk.run();
}
Note: This also applies to the BLYNK_READ & BLYNK_WRITE handlers!
SOLUTION: If you need to perform actions in time intervals - use timers, for example BlynkTimer.
If your code frequently sends a lot of requests to our server, your hardware will be disconnected. Blynk App may show "Your hardware is offline"
When Blynk.virtualWrite
is in the void loop
, it generates hundreds of "writes" per second
Here is an example of what may cause flood. DON'T DO THAT:
void loop()
{
Blynk.virtualWrite(1, value); // This line sends hundreds of messages to Blynk server
Blynk.run();
}
SOLUTION: If you need to perform actions in time intervals - use timers, for example BlynkTimer.
Using delay()
will not solve the problem either. It may cause another issue. Use timers!
If sending hundreds of requests is what you need for your product you may increase flood limit on local server
and within Blynk library.
For local server you need to change user.message.quota.limit
property within server.properties
file :
#100 Req/sec rate limit per user.
user.message.quota.limit=100
For library you need to change BLYNK_MSG_LIMIT
property within BlynkConfig.h
file :
//Limit the amount of outgoing commands.
#define BLYNK_MSG_LIMIT 20
To enable debug prints on the default Serial, add this on the top of your sketch (it should be the first line in your sketch):
#define BLYNK_DEBUG // Optional, this enables lots of prints
#define BLYNK_PRINT Serial
And enable serial in void setup()
:
Serial.begin(9600);
You can also use spare Hardware serial ports or SoftwareSerial for debug output (you will need an adapter to connect to it with your PC).
Note: enabling debug mode will slow down your hardware processing speed up to 10 times.
Geo DNS issue is no longer a problem. It was solved in 2017.
On login screen click on "Forgot password?" label and than type your email and Send
button.
You'll get instruction on your email.
- Open instruction email from your smartphone or tablet;
- Click on "Reset now" button in your email;
- Click on Blynk icon in below popup and reset the pass: