Downloads

1.38 (Dec. 15, 2025)

Filename: lc40_1_38.bin (1.7 MB)

Added

• New authentication system.
  • Login on the web interface is integrated with Basic Authentication. Previously, there were two login forms — one handled by the browser using Basic Authentication and another on the Login page.
  • Basic Authentication is enabled by default.
  • With default settings, i.e. with Basic Authentication enabled, access credentials are properly protected. An issue was removed where a user could read admin credentials.
    Please note that the admin/user separation previously served only a visual purpose and did not provide real access control. It now fulfills both roles — providing access to a simplified view for user and a full configuration view for admin, with proper separation of access rights to resources.
• Extension of the HTTP client functionality with the ability to select the request method: POST, PUT, PATCH (in addition to GET), define headers, and define the request body (text only, not binary).
• Support for Digest Authentication in the HTTP client. It uses credentials provided in the URL field in the user:pass@ format.
• Support for the MLX90614 sensor over I²C.
• (LTE version only) CLIP function — reacting to an incoming call from a trusted number by switching the OUT output or a VAR variable.
• Support for a new API in the Dynamic energy prices function: https://spotovaelektrina.cz/api.
• Wi-Fi IP in readout codes (001) and for sending via the MQTT client.
• UI:
  • Automatic selection of the first free position when using the clone/copy options for Events and Schedule entries (it is still possible to manually select a different, later position).
  • Shortcut button for editing the configuration of a custom Modbus module at the position where this module is selected (allows faster changes to Modbus presets).
  • Ability to download and install a new firmware version after checking availability, directly from the web interface.
  • Device name (hostname) displayed as a tooltip on the link to the home page (the LK4 label on the top bar).
  • Warning about SMS text length limitations.

Changed

• Extension of the MQTT topic prefix length in the MQTT client from 14 to 32 characters.
• Value range for the interval between Modbus register reads changed from <0.1, 22.5> to <0.001, 0.255> s.
• Reduction of the time interval between reads of consecutive Modbus devices — effectively from 1000 ms to 200 ms, allowing more frequent data reads from Modbus modules.
• UI:
  • Inclusion in the settings migration function of: access credentials (usernames and passwords), I²C readout names, INA740 and MLX90614 (I²C) options, Modbus TCP server enable option, pressure calibration, CLIP function options in the LTE modem, and HTTP client options (method, headers, body).
  • Separation of the MAC address from network settings in the settings migration function. This simplifies cloning settings across multiple devices.
  • The settings migration function updates the interface state during import, e.g. changes the interface language.
  • Removal of delays between saving consecutive parameters in the settings migration function, resulting in a significantly shorter import time.
  • Display of information in the UI for occurrences of variable m1 about its usage in the dynamic energy prices function (if it is actually active), e.g. in selection lists in Events.
  • Validation of the E-mail form now allows setting an empty password and username.
  • Removal of the automatic login feature due to incompatibility with the new authentication system.

Fixed

• DNS handling with static network settings (without DHCP).
• SNMP Trap message structure (incorrect fixed OID and its value).
• Incorrect ON and OFF times in the automatic OUT output switching mode:
  • the ON time could be swapped with the OFF time, depending on the output state at the moment the function was enabled,
  • execution times realized by the device did not match the configured ones — they were extended by approx. 50%.
• Divider handling for int16 variables in the custom Modbus module (it was previously ignored).
• Saving users with permissions to control OUT outputs above 10 entries (authUser11-50).
• State of conditions dependent on digital inputs INPD in the Events function — state changes could be observed that did not actually occur. Although this did not trigger event entries, it could be misleading.
• Handling of parameter A for the Uptime readout code.
• URL storage in the HTTP client.
• Sending variables m1–m30 in the HTTP and MQTT clients — sent in the same format as displayed on the web interface, i.e. with a fractional part.
• Remembering the state of OUT outputs when the Keep state after restart function is enabled.
• VBUS measurement in the INA740.
• Modbus TCP addresses — now consistent with those displayed; previously there was an incorrect offset of −1, e.g. a value from address 1000 was actually read from address 999.
• Reading variables for the Sofarsolar module via Modbus.
• MQTT ID is now derived from the original MAC address, not the configured one.
• Extending the MQTT ID from 6 to 8 characters. In test data, we observed duplicate identifiers at 6 characters long, which could result in MQTT clients disconnecting from each other when attempting to connect to the same server from two LKs with the same ID. This change addresses this issue.
• Extension of the MQTT ID length from 6 to 8 characters. In test data, we observed duplicate IDs with 6-character long, which could cause mutual disconnections of MQTT clients from two LK devices with the same ID. This change addresses this issue.
• Updated handling of the dynamic energy prices API.
• Setting the value 31 for minutes and seconds in the Scheduler.
• Execution times of Scheduler actions. Previously, executions could be skipped or duplicated.
• Pulse counting on INPD inputs (counting from one INPD input in one Power/Energy position could be incorrectly added to another Power/Energy position with a different INPD input as the source).
• Returning ping values from the device on timeout and displaying the appropriate state in the UI (65535 value and Timed out message) in the Watchdog function.
• UI:
  • Handling of a restart limit equal to 0 in the Watchdog function — allows the function to run indefinitely.
  • Handling of file versions in the settings migration function.
    Importing settings from newer software into older software is not recommended. It is recommended to use the same software version or migrate from older to newer.
  • Parsing and formatting requests sent from the web interface to the device to avoid exceeding the request length limit (approx. 1800 characters).
  • Parsing and sending of the mqttSendChanges option (it could previously be set incorrectly — an invalid value instead of 0/1).
  • Setting and displaying the device name (hostname) in the page title shortly after visiting the page (the name is already set on the login page).
  • PWM duty cycle control is inactive in the user view (the slider and input field are visible but not interactive).
  • Unit for power measurement in the INA740 sensor.
  • Dynamic energy prices API addresses.

1.24 (Jan. 3, 2025)

Filename: lc40_1_24.bin (1.8 MB)

Added

• RESTART action to the Events function (like in the Scheduler, used to restart the device).
• Reading dynamic energy prices. The value is read cyclically every 15 minutes and after enabling the function, and saved in the powerPriceFVal and mValue1 variables (remember that the m1 variable can be used in the Events function, MQTT client, texts in the HTTP client, OLED and LTE Modem). The function is configurable in the Power and Energy tab.
• Support for the INA740 sensor via I2C.
• Dark mode with a switch on the top bar.
• Ability to automatically sign in as a user with a special link /#/?signIn=user when the Automatic sign in function is enabled.

Changed

• Many UI/UX improvements:
  • Unified tables styling.
  • Modbus page layout.
  • Unified placement of icons on buttons.
  • Increased default size of modem console and added the prefix $ for user input.
  • Changed the backup filename to include more information.
  • HTTP client URL validation allows using :`! in the path section.
  • Restart limit validation in Watchdog allows setting the value to 0 (no limit).
  • Displaying the names of mapped readings (more detailed).
  • Firmware verification after updating from the device's WWW page can help with the occasional problem of incorrectly uploading the WWW part during the update. Currently, the solution is to re-upload the firmware.
  • Ability to change the DS name in the I2C and 1-Wire sensors tab.
  • I2C and 1-Wire Sensors page layout using tabs (presentation of extended 1-Wire and I2C sections).
  • Removed limitations on setting the action on/off delay in Events (they were only available for OUT/PWM/VAR actions).
  • The Watchdog page layout separates the configuration and information sections.
  • Fixed refreshing PM and CO2 values in I2C and 1-Wire Sensors page.
  • Fixed saving the form in the Network tab (when changing from DHCP to static settings).
  • Refreshing Wi-Fi connection details after saving changes in the form.
  • A function that checks the availability of the LTE Modem when visiting the page. The LTE Modem tab may become unavailable after restarting the device, in which case, it is necessary to reload the page. The LTE Modem tab is only available in the LK4 LTE variant.

Fixed

• Reading AM2320.
• RESET ENERGYX action in Events.
• Set output after starting function (OUT outputs). Problem with times above 59 seconds, as a reminder the limit is 65535 seconds.
• Cyclic sending of HTTP and MQTT data (problem with inaccurate sending period).
• The operation of the user list for controlling OUT outputs. In the Access tab, you can add users who can control OUT outputs using the commands /api/v1/save/?outX=Y and /api/v1/save/?out=outX. Please note that the function only works when Basic Authentication is enabled and is not used to sign in to the device page.
• Energy counting using INPD pulse inputs (problem with resetting the counted energy when resetting the device).

1.18a (June 20, 2024)

Filename: lc40_1_18a.bin (1.8 MB)

Changed

• Removed mqttModem and httpModem options - LK automatically manages network interface priorities (Ethernet, Wi-Fi and LTE).

Fixed

• Action MQTT in the Events function. Additionally, for the MQTT CONNECTION input in the first condition, the MQTT action has no effect.
• PWM frequency range 1 Hz - 1 MHz.
• Saving energy status after reset. As a reminder: energy is saved approximately every 5 minutes after enabling the function.
• Setting OUT outputs after reset (Keep state after restart function), specifically for OUT2 - OUT6 outputs.
• Modbus reading - fixed operation of the Endian option.
• Operation of the pwmX=Y command (setting a given value at the PWM output).
• Counting energy when using the INPD logical input for counting pulses. After setting its new state with the energySetX=Y command, energy was no longer counted.
• Action SMS in the Events function (sending SMS with the action variant when the condition is no longer met).
• Receiving empty MQTT messages - now they are ignored.
• Cyclic sending of pwmDuty in the MQTT client - now the values ​​of pwmDutyX variables are sent correctly.
• Data migration function - when uploading data from an older SW version, it only applies corrections when needed (e.g. setting event with a value for the mode option).
• Presentation of data in tables, e.g. events and schedule. The indicated row is highlighted to make it easier to read the values ​​set in it.

1.13 (May 13, 2024)

Filename: lc40_1_13.bin (1.8 MB)

Added

• TLS option in E-mail function, allows you to choose without encryption, StartTLS and SSL/TLS. Previously, only StartTLS was supported.

Changed

• Number of WiFi connection attempts when the device is turned on or after disconnection from 2 to 1000 (approximately 40 minutes)

Fixed

• SNMP operation - fixed problems with reloading settings and their incorrect application.

1.10c (Jan. 31, 2024)

Filename: lc40_1_10c.bin (1.8 MB)

Fixed

• Reading m1-m10 on slots 4 and 5.

1.10a (Jan. 26, 2024)

Filename: lc40_1_10a.bin (1.8 MB)

Fixed

• Support for the HTTP port option in the Network tab.
• Saving static settings for Wi-Fi in the Network tab.
• Memory leak in HTTP server with Basic Authentication enabled.
• Display time option in OLED.
• APN support for modem. After saving the new APN, an LK restart is required.
• Indexing of outputs in SMS commands.
• Reading of negative temperatures from SHTC3 (built-in temperature and humidity sensor).
• Control of OUT outputs with the Reverse state option active.

1.08 (Nov. 17, 2023)

Filename: lc40_1_08.bin (1.8 MB)