With the Fritz!Box 7390 I have already used a number of switching plugs from AVM, specifically the Fritz!DECT 200 and later also the Fritz!DECT 210. In addition to the switching function, these devices also offer measuring power consumption and temperature and can also be switched by sound if desired, e.g. when you clap your hands. However, this also has its price: currently you can get these devices, if at all, for no less than 60-70 EUR. In the past, you had to budget at least EUR 50 for it.
But since I’ve been using Home Assistant, there are also alternatives.
The Delock 11827 is a device with energy measurement in which Tasmota is already pre-installed. An ESP8266 with 1 MB memory is used as the controller.
With a sales price of around EUR 20, the device is also significantly cheaper than the solution from AVM. However, there is no temperature measurement or noise detection. On the other hand Tasmota offers a very extensive programming option with timers and you can also correct the measured values via console commands if necessary and change the switching function of the relay to permanently “on” if you want to use the devices for energy measurement only. An HTTP API to control the device is also available.
Configuration of the WiFi access
In the delivery state, the device provides its own WiFi network with the name “delock-1234”, where “1234” is a device-dependent number.
To connect the device to my own WiFi network, I used my smartphone – I established the connection to the network there and was then automatically redirected to the web interface as a “captive portal” for the WiFi configuration. This eliminates the need to search for the correct IP address.
After you have entered the access data for the WiFi network, Tasmota restarts and the device should be visible in the regular network a short time later. The exact IP address can then be found in the router’s interface. I have also specified there that the device should always get the same IP address so it can be reached at a fixed address.
Firmware update
Important: if you make mistakes during the firmware upgrade, the device can become unusable! The housing is glued and cannot be easily opened to program the controller via a cable connection if necessary – so be careful when updating and do not unplug the device during an update!
Tasmota 9.5.0 or higher is required for integration with Home Assistant. However, as of February 2023, the device will still be delivered with an older version 7.20.
Proceed as follows to update:
Perform with “Firmware Upgrade” and the following OTA-URL:
http://www.delock.de/download/firmware/11827-en.bin
This ensures that the latest version from the manufacturer is installed. After the upgrade has been completed, the Tasmota start page will be loaded again
Switch to the official Tasmota version 8.5.1 by performing a firmware upgrade again with the following OTA URL:
http://ota.tasmota.com/tasmota/release-8.5.1/tasmota.bin.gz
This upgrade also ends with a restart and the display of the new interface.
Now you can update to the current version 12.3.1 with the following URL:
http://ota.tasmota.com/tasmota/release-12.3.1/tasmota.bin.gz
Tasmota will start with a minimal firmware that performs the update:
Don’t let this confuse you – when clicking “Restart”, the system should reboot with the final firmware. Some measured values are still missing because the hardware configuration is not complete yet.
To adjust the hardware configuration, open the configuration via Configuration → Configure Other and enter the following text in “Template”:
{"NAME":"Delock 11827","GPIO":[0,0,0,32,2688,2656,0,0,2624,576,224,0,0,0],"FLAG":0,"BASE":53}
You can set emulation to “none” since it is not needed for Home Assistant. When you save the change, Tasmota will restart once. Additional information for “Apparent Power”, “Reactive Power” and “Power Factor” should then appear as a result.
Protect the web interface from misuse and change the device name
You can also set a password for the web interface under Configuration → Other. As username you generally use admin.
Here you can also change the name “WLAN-Switch” if you use several plugs and want to distinguish them from each other. That name will then later also be used as a default for the device in Home Assistant.
Enter MQTT data for Home Assistant
Home Assistant must already be configured for MQTT and Tasmota. See also my article on Home Assistant. Under Configuration → Configure MQTT, enter the data for Home Assistant as follows:
- Host: Home Assistant’s IP address
- Port: 1883
- Client:
DEV_%06X - User/Password: the data of the user used in Home Assistant for MQTT
- Topic:
tasmota_%06X - Full Topic:
%topic%/%prefix%/
After restarting Tasmota, the device should be visible in the Tasmota integration and have both a switching function and also provide measured values for power consumption.
Switching state after a power failure (PowerOnState)
The current switching state is automatically restored in the event of a power failure . However, the configuration for this can be adjusted in the console, see also https://tasmota.github.io/docs/PowerOnState/. You may also set the power to be always “on” if you only want to use the device to track energy consumption and avoid the power to be turned off by accident.
