Matter smoke detector with alarm sounder - How to activate the alarm on the Heiman HS1SA-M smoke detector

The Matter smoke detector HS1SA-M by Heiman is currently the only known Matter smoke detector whose siren can be actively triggered via Home Assistant. A prerequisite for this is an optional firmware update - this only requires one setting in the configuration of the "Matter Server" app.

Updates 06/29/2026:

Overview of the versions:

Official versions: 1.7 (newest) 1.6, 1.5, and 1.0

1.7: Fixes errors that occurred in connection with these LIT-ICD functions (Low Idle Time / Idle mode Client-Driven), e.g., problems with connection establishment, reachability, or subscription behavior of Matter controllers (HA, Apple Home, etc.)

1.6: The contact frequency of the sensor has been increased here, as Apple in particular sets the "Thread Child Timeout" relatively short, which then leads to the "de-registration" of the HS1SA-M from the Thread network. If the HS1SA-M should still lose its connection, the connection can be re-established by clicking the pairing button 3 times (not the test button, but the small hole with the pairing pin). 

Optional versions: 4.3 (beta) 4.2, 4.1, 1.4, and 1.1 

4.3: The siren can now be displayed as a siren entity. Further optimizations to avoid connection drops.
4.2: The contact frequency of the sensor has been increased here, as Apple in particular sets the "Thread Child Timeout" relatively short, which then leads to the "de-registration" of the HS1SA-M from the Thread network.  

For the optional updates, the versioning has jumped to 4.x so that an OTA of an official update does not overwrite an optional update.

Important new feature: Optional update is now very easy:

1. Prerequisite: min. Home Assistant Core version 2026.6
2. If the options "Use the latest beta version" and "Enable test-net DCL usage" are activated in the "Matter Server" app under the "Configuration" tab, the firmware update to version 4.3 will be suggested automatically.
3. Perform update. This can take a while and in some cases 0% instead of 100% is displayed at the end. Don't worry.
4. After the update, restart Home Assistant.
5. After the HA restart, restart the Matter Server again
   
    
6. Wait 2 minutes. The siren symbol should now be visible and display firmware 4.3.
   
    

Important notes:

• The firmware update is not officially publicly documented, but is provided by Heiman.
• Firmware updates cannot be undone. If you are on 4.2, there is no way to return to an official version.  
• The alarm can be loud and, depending on the Thread network, can trigger with a delay of a few seconds – only test in a controlled manner!
• Matter allows the siren to be controlled like a real siren entity – ideal for security functions.
• In Home Assistant and Apple Home, the siren is displayed like a light switch. Caution! (Note: Another release should display the activation of the siren differently by April 2026).

!The manual update procedure is described below, but is no longer necessary:

Prerequisites for the firmware update to 4.2

• Home Assistant with Matter integration via the "Matter Server" add-on
• The HS1SA-M smoke detector is already connected
• Access to the Home Assistant file system (e.g., via File Editor). Important: Unrestricted access to the file system must be guaranteed.
• Current firmware version must be lower than 4.2.
• Before you start, read the notes at the very bottom of the blog.

Preparing the firmware update to 4.2

You need to install an update that is currently not automatically offered via OTA. You activate it manually via a JSON file:

1. Open the directory:
   /addon_configs/core_matter_server/updates/
   Note 1: It is best to use the File Editor. In the configuration of the "File Editor" add-on, "Enforce Basepath" must be deactivated (don't forget to save).
   
   Note 2: If the "updates" folder does not yet exist, it must be created first.
2. Create a file in this directory named:
   HeimanD1TestNet.json
3. Paste this content:
   Copy

   
   {
    "modelVersion":{
    "vid":4619,
    "pid":4099,
    "softwareVersion":66,
    "softwareVersionString":"4.2",
    "cdVersionNumber":1,
    "softwareVersionValid":true,
    "otaUrl":"https://heimanfile.oss-cn-shenzhen.aliyuncs.com/2114161f6e5e4b4da47f7b187a741582.ota",
    "otaChecksum":"HB2zjVutI3n1D54QTcOa6r1SpjdosKt5WnKXwvaYiag=",
    "otaChecksumType":1,
    "minApplicableSoftwareVersion":1,
    "maxApplicableSoftwareVersion":1000
     }
   }
   

4. Restart Home Assistant.
5. Restart the Matter Server add-on (yes, even though it was already started with the Home Assistant restart, the Matter Server add-on must be restarted separately).
6. After the restart, go to the Matter Server web interface and update the smoke detector node (by clicking on "Update"). The update takes quite a long time due to the low bandwidth – be patient. It may happen that the display jumps back to 0% after 99% – ignore it.
   
7. Restart Matter Server again (not HA, just the app).
8. Finished

🚨 Triggering the alarm via Home Assistant

After the update, you can start the alarm manually in the device details or switch it on or off via automation:

Important notes

• The firmware update is not officially publicly documented, but is provided by Heiman.
• Firmware updates cannot be undone. If you are on 4.2, there is no way to return to an official version.  
• The alarm can be loud and, depending on the Thread network, can trigger with a delay of a few seconds – only test in a controlled manner!
• Matter allows the siren to be controlled like a real siren entity – ideal for security functions.
• In Home Assistant and Apple Home, the siren is displayed like a light switch. Caution! (Note: Another release should display the activation of the siren differently by April 2026).