What kind of cat loves raspberry?

…actually I know one, who is a huge fan of Raspberry Pi…it’s CHOCOLATE from the ConfigCat team 🙂

Ingredients:

• Raspberry Pi 2/3 with:
• python3
• ConfigCat python SDK
• (‘GPIO Zero’ integration to any hardware) - optional
• ConfigCat subscription (free plan is enough :))

Step 0. – Prepare the device to run your code

I use my board with Raspbian OS but you can use any distribution. I prefer it because it (usually :)) contains all necessary components for my pet projects. Read more about Raspberry Pi OS installation here.

install ConfigCat

Install ConfigCat SDK with pip:

sudo pip3 install configcat-client

install gpiozero libs

By default the Raspbian desktop image contains the GPIO Zero package. On a different OS, you’ll have to use PIP:

sudo pip3 install gpiozero

Step 1. – Set up your ConfigCat project

Log in to ConfigCat

1. Create a feature flag
2. Copy your SDK Key from the SDK Key tab.

Step 2. – Code

Create a file (e.g. remoteswitch.py) with your favourite editor (I prefer nano) and implement the following code:

from gpiozero import OutputDeviceimport timeimport configcatclient
# set GPIO#3 port (you can select any GPIO output port)relay = OutputDevice(3)
# initialize ConfigCat client to get your setting valueclient = configcatclient.create_client_with_manual_poll('YOUR_SDK_KEY')
while True:
        # get the latest value        client.force_refresh()
        # save into 'my_remoteswitch' variable        my_remoteswitch = client.get_value('demoswitch', False)
        # for debug purpose only        print(my_remoteswitch)
        # depend on the value the condition turns on/off the output        if my_remoteswitch == True:                relay.on()        else:                relay.off()
        time.sleep(5)
pause()

In line 9 you should add your own SDK KEY. This solution uses the ConfigCat SDK’s in manual polling mode. (Read more about polling modes here).

Step 3. – Test

Run your code with the following:

python3 remoteswitch.py

Depending on the value of setting the program prints the actual value of your switch on the ConfigCat Dashboard and turns on/off the OutputDevice as well.

Step 4. – Demo

For the demonstration I created a simple circuit.

The components I have used:

• LED diode to show the switch status
• one resistor to limit the current (500Ω)
• two wires to connect to GPIO#3 port and a ground
• Raspberry Pi to serve power to the LED (you won’t need external power supply)

Step 5. – Further development possibilities

• Set up a program as a daemon (always run, after reboot)
• Apply this solution with any wireless power switch on your home