Prepare MySQL-Database for pushjet

# mysql -u root -p
CREATE USER 'pushjet'@'localhost' IDENTIFIED WITH mysql_native_password AS '***';
GRANT USAGE ON *.* TO 'pushjet'@'localhost' REQUIRE NONE WITH MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 MAX_USER_CONNECTIONS 0;
CREATE DATABASE IF NOT EXISTS `pushjet`;
GRANT ALL PRIVILEGES ON `pushjet`.* TO 'pushjet'@'localhost'

Install gunicorn and pushjet via Shell

sudo su
apt-get install gunicorn python-pip libmysqlclient-dev
cd /opt
wget https://github.com/Pushjet/Pushjet-Server-Api/archive/master.zip
unzip master.zip
rm master.zip
mv Pushjet-Server-Api-master/ pushjet
cd pushjet
pip install -r requirements.txt
cp config{.example,}.py
cat database.sql | mysql -uroot -p{insert root password} -D pushjet

Create gunicorn config for pushjet /etc/gunicorn.d/pushjet

CONFIG = {
  'mode': 'wsgi',
  'working_dir': '/opt/pushjet/',
  'python': '/usr/bin/python2',
  'args': (
    '--bind=0.0.0.0:8080',
    '--workers=2',
    '--timeout=30',
    'application:app',
  ),

Modify pushjet config /opt/pushjet/config.py

# Must be a mysql database!
database_uri = 'mysql://pushjet:password@localhost/pushjet'
# Google Cloud Messaging configuration (required for android!)
google_api_key = 'ABCDEF....XYZ' 
# Change this to your FCM server key
google_gcm_sender_id = 512345678900 
# Change this to your GCM sender id

How to create the required key and id is documented here.

Create apache site config
/etc/apache2/sites-available/pushjet.conf

<VirtualHost *:443>
    SSLEngine On
    SSLCertificateFile /path/to/fullchain.pem
    SSLCertificateKeyFile /path/to/privkey.pem
    ServerAdmin root@my-push-domain.org
    ServerName my-push-domain.org
    ServerAlias my-push-domain.org
    RequestHeader set Front-End-Https "On"
    Header edit Location "^http:(.*)$" "https:$1"
    ProxyPass / unix:/var/run/gunicorn/pushjet.sock|http://localhost/
    RedirectMatch ^/$ http://my-push-domain.org/
</VirtualHost>

Alternatively you can also publish pushjet as sub directory

<Location /pushjet> 
    ProxyPass unix:/var/run/gunicorn/pushjet.sock|http://localhost/
</Location>

Enable the apache site and restart gunicorn and apache

sudo a2ensite pushjet.conf
systemctl restart gunicorn
systemctl restart apache2.service

Test it

To test it just go to https://my-push-domain.org/gcm
The result should look like this:

{
  "sender_id": 512345678900
}

Configure Pushjet Client

Open the pushjet settings:
Server URL: http://my-push-domain.org/
Custom Sender ID: 512345678900

The Sonoff S20 has only a 4 pin header (GND, TX, RX, VCC).

To use this pins (TX=GPIO1, RX=GPIO3) for sensors, the serial interface has to be disabled:
Tools – Advanced – Enable Serial port: uncheck

Now it is possible to use gpio1 and gpio3 for Devices:

This is the first test on a breadboard with DHT11

I don’t think that a humidity sensor makes any sense inside the socket. Therefore, I think I will use DS12B20 soldered on a female pin header in the final version.

And this is the result:

The values are also published via mqtt:

# mosquitto_sub -h 192.168.234.100 -t "#" -v
/sonoff-s20/DHT11/Temperature 24.00
/sonoff-s20/DHT11/Humidity 33.00

Flash espeasy

Image can be found here.
To boot the sonoff into flash mode, press and hold the button while connecting it to power.

./esptool.py --port /dev/ttyUSB0 write_flash 0x000 ESPEasy_R120_1024.bin -fs 8m

Connect to wifi and configure

Connect to ESP_0 with password configesp and set up the wifi connection.

After connecting to wifi open the webinterface http://ip.of.sonoff/config and configure the name and unit number. The name of my sonoff is sonoff-s20.

Configure Hardware and Devices.

Enable rules: Tools – Advanced – Rules: Checked

Now there is a new menu entry named Rules

On Button#State=1 do
  if [Relay#State]=0
    gpio,12,1
  else
    gpio,12,0
  endif
endon

Now you can toggle the relay with the button.

MQTT usage

I use the protocol OpenHAB MQTT. So I can subscribe these events:

# mosquitto_sub -h my.mqtt.server -t "#" -v
/sonoff-s20/Relay/State 1
/sonoff-s20/Relay/State 0

To switch on and off you can publish these messages:

# mosquitto_pub -h 192.168.234.100 -t "/sonoff-s20/gpio/12" -m "1"
# mosquitto_pub -h 192.168.234.100 -t "/sonoff-s20/gpio/12" -m "0"

It is also possible to change „Relay“ to „gpio“ and „State“ to „12“. In this case, the subscribed and published strings are the same, but the rules also have to be modified.

openHAB configuration

After configuration of the mqtt-binding in openhab.cfg I created a new item-file
items/sonoff.items:

Switch sonoff01 "Sonoff Socket" {mqtt=">[mosquitto:/sonoff-s20/gpio/12:command:ON:1],>[mosquitto:/sonoff-s20/gpio/12:command:OFF:0],<[mosquitto:/sonoff-s20/Relay/State:state:MAP(mqtt.map)]", autoupdate="false"}

I also created the file transforms/mqtt.map

0=OFF
1=ON