Blynk is a platform with iOS and Android apps to control Arduino, ESP8266, Raspberry Pi and the likes over the Internet.
You can easily build graphic interfaces for all your projects by simply dragging and dropping widgets.
If you need more information, please follow these links:
- Blynk site
- Blynk docs
- Blynk community
- Blynk Examples generator
- App Store
- Google Play
- Blynk library
- Kickstarter
- Download
- Requirements
- Quick Local Server setup
- Enabling mail on Local server
- Quick local server setup on Raspberry PI
- Enabling server auto restart on unix-like systems
- Enabling server auto restart on Windows
- Update instruction for unix-like systems
- Update instruction for Windows
- App and sketch changes for Local Server
- Advanced local server setup
- Administration UI
- HTTP/S RESTful API
- Enabling sms on local server
- Enabling raw data storage
- Automatic Let's Encrypt Certificates
- Manual Let's Encrypt SSL/TLS Certificates
- Generate own SSL certificates
- Install java for Ubuntu
- How Blynk Works?
- Blynk Protocol
Blynk Server is an Open-Source Netty based Java server, responsible for forwarding messages between Blynk mobile application and various microcontroller boards and SBCs (i.e. Arduino, Raspberry Pi. etc).
Download latest server build here.
- Java 8/10 required (OpenJDK, Oracle)
- Any OS that can run java
- At least 30 MB of RAM (could be less with tuning)
- Open ports 9443 (for app), 8080 (for hardware without ssl), 8441 (for hardware with ssl)
Ubuntu java installation instruction.
For Windows download Java here and install.
-
Make sure you are using Java 10
java -version Output: java version "10"
-
Run the server on default 'hardware port 8080' and default 'application port 9443' (SSL port)
java -jar server-0.39.8.jar -dataFolder /path
That's it!
NOTE: /path
should be real existing path to folder where you want to store all your data.
-
As an output you should see something like that:
Blynk Server successfully started. All server output is stored in current folder in 'logs/blynk.log' file.
To enable mail notifications on Local server you need to provide your own mail credentials. Create file mail.properties
within same folder where server.jar
is.
Mail properties:
mail.smtp.auth=true
mail.smtp.starttls.enable=true
mail.smtp.host=smtp.gmail.com
mail.smtp.port=587
mail.smtp.username=YOUR_EMAIL_HERE
mail.smtp.password=YOUR_EMAIL_PASS_HERE
Find example here.
WARNING : only gmail accounts are allowed.
NOTE : you'll need to setup Gmail to allow less secured applications. Go here and then click "Allow less secure apps".
-
Login to Raspberry Pi via ssh;
-
Install java 8:
sudo apt-get install oracle-java8-jdk
-
Make sure you are using Java 8
java -version Output: java version "1.8"
-
Download Blynk server jar file (or manually copy it to Raspberry Pi via ssh and scp command):
wget "https://github.com/blynkkk/blynk-server/releases/download/v0.39.8/server-0.39.8-java8.jar"
-
Run the server on default 'hardware port 8080' and default 'application port 9443' (SSL port)
java -jar server-0.39.8-java8.jar -dataFolder /home/pi/Blynk
That's it!
-
As output you will see something like that:
Blynk Server successfully started. All server output is stored in current folder in 'logs/blynk.log' file.
-
Install Docker
-
Run Docker container
docker run -p 8080:8080 -p 8441:8441 -p 9443:9443 mpherg/blynk-server
That's it!
-
To enable server auto restart find /etc/rc.local file and add:
java -jar /home/pi/server-0.39.8.jar -dataFolder /home/pi/Blynk &
-
Or if the approach above doesn't work, execute
crontab -e
add the following line
@reboot java -jar /home/pi/server-0.39.8.jar -dataFolder /home/pi/Blynk &
save and exit.
-
Create bat file:
start-blynk.bat
-
Put in it one line:
java -jar server-0.39.8.jar -dataFolder /home/pi/Blynk
-
Put bat file to windows startup folder
You can also use this script to run server.
IMPORTANT Server should be always updated before you update Blynk App. To update your server to a newer version you would need to kill old process and start a new one.
-
Find process id of Blynk server
ps -aux | grep java
-
You should see something like that
username 10539 1.0 12.1 3325808 428948 pts/76 Sl Jan22 9:11 java -jar server-0.39.8.jar
-
Kill the old process
kill 10539
10539 - blynk server process id from command output above.
- Start new server as usual
After this steps you can update Blynk app. Server version downgrade is not supported.
WARNING! Please do not revert your server to lower versions. You may loose all of your data.
-
Open Task Manager;
-
Find Java process;
-
Stop process;
-
Start new server as usual
- Specify custom server path in your application
-
Change your ethernet sketch from
Blynk.begin(auth);
to
Blynk.begin(auth, "your_host", 8080);
or to
Blynk.begin(auth, IPAddress(xxx,xxx,xxx,xxx), 8080);
-
Change your WIFI sketch from
Blynk.begin(auth, SSID, pass));
to
Blynk.begin(auth, SSID, pass, "your_host", 8080);
or to
Blynk.begin(auth, SSID, pass, IPAddress(XXX,XXX,XXX,XXX), 8080);
-
Change your rasp PI javascript from
var blynk = new Blynk.Blynk(AUTH, options = {connector : new Blynk.TcpClient()});
to
var blynk = new Blynk.Blynk(AUTH, options= {addr:"xxx.xxx.xxx.xxx", port:8080});
-
or in case of USB when running blynk-ser.sh provide '-s' option with address of your local server
./blynk-ser.sh -s you_host_or_IP
IMPORTANT Blynk is being constantly developed. Mobile apps and server are updated often. To avoid problems during updates either turn off auto-update for Blynk app, or update both local server and blynk app at same time to avoid possible migration issues.
IMPORTANT Blynk local server is different from Blynk Cloud server. They are not related at all. You have to create new account when using Blynk local server.
For more flexibility you can extend server with more options by creating server.properties
file in same folder as server.jar
.
Example could be found here.
You could also specify any path to server.properties
file via command line argument -serverConfig
. You can
do the same with mail.properties
via -mailConfig
and sms.properties
via -smsConfig
.
For example:
java -jar server-0.39.8.jar -dataFolder /home/pi/Blynk -serverConfig /home/pi/someFolder/server.properties
Available server options:
-
Blynk app, https, web sockets, admin port
https.port=9443
-
Http, hardware and web sockets port
http.port=8080
-
Hardware ssl/tls port (for hardware that supports SSL/TLS sockets)
hardware.ssl.port=8441
-
For simplicity Blynk already provides server jar with built in SSL certificates, so you have working server out of the box via SSL/TLS sockets. But as certificate and it's private key are in public this is totally not secure. So in order to fix that you need to provide your own certificates. And change below properties with path to your cert. and private key and it's password. See how to generate self-signed certificates here
#points to cert and key that placed in same folder as running jar. server.ssl.cert=./server_embedded.crt server.ssl.key=./server_embedded.pem server.ssl.key.pass=pupkin123
-
User profiles folder. Folder in which all users profiles will be stored. By default System.getProperty("java.io.tmpdir")/blynk used. Will be created if not exists
data.folder=/tmp/blynk
-
Folder for all application logs. Will be created if it doesn't exist. "." is dir from which you are running script.
logs.folder=./logs
-
Log debug level. Possible values: trace|debug|info|error. Defines how precise logging will be. From left to right -> maximum logging to minimum
log.level=trace
-
Maximum allowed number of user dashboards.
user.dashboard.max.limit=100
-
100 Req/sec rate limit per user. You also may want to extend this limit on hardware side.
user.message.quota.limit=100
-
this setting defines how often you can send mail/tweet/push or any other notification. Specified in seconds
notifications.frequency.user.quota.limit=60
-
Maximum allowed user profile size. In Kb's.
user.profile.max.size=128
-
Number of strings to store in terminal widget (terminal history data)
terminal.strings.pool.size=25
-
Maximum allowed number of notification queue. Queue responsible for processing email, pushes, twits sending. Because of performance issue - those queue is processed in separate thread, this is required due to blocking nature of all above operations. Usually limit shouldn't be reached
notifications.queue.limit=5000
-
Number of threads for performing blocking operations - push, twits, emails, db queries. Recommended to hold this value low unless you have to perform a lot of blocking operations.
blocking.processor.thread.pool.limit=6
-
Period for flushing all user DB to disk. In millis
profile.save.worker.period=60000
-
Specifies maximum period of time when hardware socket could be idle. After which socket will be closed due to non activity. In seconds. Leave it empty for infinity timeout
hard.socket.idle.timeout=15
-
Mostly required for local servers setup in case user want to log raw data in CSV format. See [raw data] (#raw-data-storage) section for more info.
enable.raw.data.store=true
-
Url for opening admin page. Must start from "/". For "/admin" url path will look like that "https://127.0.0.1:9443/admin".
admin.rootPath=/admin
-
Comma separated list of administrator IPs. Allow access to admin UI only for those IPs. You may set it for 0.0.0.0/0 to allow access for all. You may use CIDR notation. For instance, 192.168.0.53/24.
allowed.administrator.ips=0.0.0.0/0
-
Default admin name and password. Will be created on initial server start
[email protected] admin.pass=admin
-
Host for reset password redirect and certificate generation. By default current server IP is taken from "eth" network interface. Could be replaced with more friendly hostname. It is recommended to override this property with your server IP to avoid possible problems of host resolving.
server.host=blynk-cloud.com
-
Email used for certificate registration, could be omitted in case you already specified it in mail.properties.
Blynk server provides administration panel where you can monitor your server. It is accessible at this URL:
https://your_ip:9443/admin
WARNING Please change default admin password and name right after login to admin page. THIS IS SECURITY MEASURE.
WARNING
Default allowed.administrator.ips
setting allows access for everyone. In other words,
administration page available from any other computer. Please restrict access to it via property allowed.administrator.ips
.
-
Paste in chrome
chrome:https://flags/#allow-insecure-localhost
-
You should see highlighted text saying: "Allow invalid certificates for resources loaded from localhost". Click enable.
Blynk HTTP/S RESTful API allows to easily read and write values to/from Pins in Blynk apps and Hardware. Http API description could be found here.
To enable SMS notifications on Local Server you need to provide credentials for SMS gateway (currently Blynk server
supports only 1 provider - Nexmo. You need to create file sms.properties
within same folder where server.jar is.
nexmo.api.key=
nexmo.api.secret=
And fill in the above properties with the credentials you'll get from Nexmo. (Account -> Settings -> API settings). You can also send SMS over email if your cell provider supports that. See discussion for more details.
By default raw data storage is disabled (as it consumes disk space a lot).
When you enable it, every Blynk.virtualWrite
command will be saved to DB.
You will need to install PostgreSQL Database (minimum required version is 9.5) to enable this functionality:
Enable raw data in server.properties
:
enable.db=true
enable.raw.db.data.store=true
sudo sh -c 'echo "deb http:https://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" >> /etc/apt/sources.list.d/pgdg.list'
wget -q https://www.postgresql.org/media/keys/ACCC4CF8.asc -O - | sudo apt-key add -
sudo apt-get update
sudo apt-get install postgresql postgresql-contrib
sudo apt-get update
apt-get --no-install-recommends install postgresql-9.6 postgresql-contrib-9.6
wget https://raw.githubusercontent.com/blynkkk/blynk-server/master/server/core/src/main/resources/create_schema.sql
wget https://raw.githubusercontent.com/blynkkk/blynk-server/master/server/core/src/main/resources/reporting_schema.sql
mv create_schema.sql /tmp
mv reporting_schema.sql /tmp
Result:
/tmp/create_schema.sql
/tmp/reporting_schema.sql
Copy it to clipboard from your console.
sudo su - postgres
psql
\i /tmp/create_schema.sql
\i /tmp/reporting_schema.sql
/tmp/create_schema.sql
- is path from step 4.
You should see next output:
postgres=# \i /tmp/create_schema.sql
CREATE DATABASE
You are now connected to database "blynk" as user "postgres".
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE TABLE
CREATE ROLE
GRANT
GRANT
\q
Now start your server and you should see next text in postgres.log
file :
2017-03-02 16:17:18.367 - DB url : jdbc:postgresql:https://localhost:5432/blynk?tcpKeepAlive=true&socketTimeout=150
2017-03-02 16:17:18.367 - DB user : test
2017-03-02 16:17:18.367 - Connecting to DB...
2017-03-02 16:17:18.455 - Connected to database successfully.
WARNING: Raw data may consume your disk space very quickly!
Data format is:
value,timestamp,deviceId
For example:
10,1438022081332,0
Where 10
- value of pin.
1438022081332
- the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC.
To display the date/time in excel you may use formula:
=((COLUMN/(60*60*24)/1000+25569))
0
- device id
Latest Blynk server has super cool feature - automatic Let's Encrypt certificates generation. However, it has few requirements:
-
Add
server.host
property inserver.properties
file. For example :server.host=myhost.com
IP is not supported, this is the limitation of Let's Encrypt. Also have in mind that myhost.com
should be resolved by public DNS severs.
-
Add
contact.email
property inserver.properties
. For example : -
You need to start server on port 80 (requires root or admin rights) or make port forwarding to default Blynk HTTP port - 8080.
That's it! Run server as regular and certificates will be generated automatically.
-
First install certbot on your server (machine where you going to run Blynk Server)
wget https://dl.eff.org/certbot-auto chmod a+x certbot-auto
-
Generate and verify certificates (your server should be connected to internet and have open 80/443 ports)
./certbot-auto certonly --agree-tos --email YOUR_EMAIL --standalone -d YOUR_HOST
For example
./certbot-auto certonly --agree-tos --email [email protected] --standalone -d blynk.cc
-
Then add to your
server.properties
file (in folder with server.jar)server.ssl.cert=/etc/letsencrypt/live/YOUR_HOST/fullchain.pem server.ssl.key=/etc/letsencrypt/live/YOUR_HOST/privkey.pem server.ssl.key.pass=
-
Generate self-signed certificate and key
openssl req -x509 -nodes -days 1825 -newkey rsa:2048 -keyout server.key -out server.crt
-
Convert server.key to PKCS#8 private key file in PEM format
openssl pkcs8 -topk8 -inform PEM -outform PEM -in server.key -out server.pem
If you connect hardware with USB script you have to provide an option '-s' pointing to "common name" (hostname) you did specified during certificate generation.
As an output you'll retrieve server.crt and server.pem files that you need to provide for server.ssl properties.
sudo add-apt-repository ppa:linuxuprising/java
sudo apt-get update
sudo apt-get install oracle-java10-installer
or if above doesn't work:
sudo apt-add-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer
sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080
sudo iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 9443
sudo apt-get install libxrender1
If you want to run Blynk server behind WiFi-router and want it to be accessible from the Internet, you have to add port-forwarding rule on your router. This is required in order to forward all of the requests that come to the router within the local network to Blynk server.
Blynk has a bunch of integration tests that require DB, so you have to skip tests during build.
mvn clean install -Dmaven.test.skip=true
When hardware connects to Blynk cloud it opens either keep-alive ssl/tls connection on port 8441 or keep-alive plain tcp/ip connection on port 8080. Blynk app opens mutual ssl/tls connection to Blynk Cloud on port 443 (9443 for local servers). Blynk Cloud is responsible for forwarding messages between hardware and app. In both (app and hardware) connections Blynk uses own binary protocol described below.
Blynk transfers binary messages between the server and the hardware with the following structure:
Command | Message Id | Length/Status | Body |
---|---|---|---|
1 byte | 2 bytes | 2 bytes | Variable |
Command and Status definitions: BlynkProtocolDefs.h
Blynk transfers binary messages between the server and mobile app with the following structure:
Command | Message Id | Length/Status | Body |
---|---|---|---|
1 byte | 2 bytes | 4 bytes | Variable |
Blynk transfers binary messages between the server and websockets (for web) with the following structure:
Websocket header | Command | Message Id | Body |
---|---|---|---|
1 byte | 2 bytes | Variable |
When command code == 0, than message structure is next:
Websocket header | Command | Message Id | Response code |
---|---|---|---|
1 byte | 2 bytes | 4 bytes |
Possible response codes. Possible command codes
Message Id and Length are big endian. Body has a command-specific format.