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Web Interface Reference

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Most of the italic text below will also be shown on the controllers web interface next to the corresponding element.



DSP Frequency Filter
The DSP filter will be able to check frequencies and their bandwidth in every triggered signal. This needs a lot of CPU power.

Work in progress

The DSP filter is currently only analyzing the signal, but does not filter it. It will be implemented in a future firmware 10.x version.

Auto Adapt to Noise
When enabled, the controller sets thresholds and gains relative to the noise floor. The relative gain will not exceed your manual gain/threshold settings.


When testing new gain or threshold settings you should disable this. Otherwise you might not see any difference, as the controller will just adapt to the noise floor.

Auto Amplitude Filter
Enable this option if you have problems with specific interference, like from robotic lawn mowers. The controller saves the rate of signals grouped by their min/max amplitudes. If signals with specific amplitudes occur too often within a time period, those signals will be filtered. This option can be seen as interference mode for a specific channel. The controller has to check every signal, so the signal rate may be lower.
Should be disabled in most cases, but can help a lot in some cases.
Number of Samples
Samples which will be recorded for each event for all channels. In most cases all of those values will be sent to the servers. Default is 512.
Please leave at 512 for normal operation. However, you can experiment with it and carry out tests.
Samples before Trigger
Include given number of samples before the trigger occurred. Default is 256.
Please leave at 256 for normal operation. However, you can experiment with it and carry out tests.
Ignore Signals below Threshold
Don't send signal for a channel when the amplitude is lower than the given percentage of it's threshold value. Set to 100% to send only values which are greater than the threshold. The intention is to save traffic for unusable signals or not working channels.
We recommend a value of 10%. For traffic saving this could be set to 100%.


IP Configuration

Toggle DHCP. If no valid DHCP answer received, the static configuration below will be used.
Note: DHCP has address collision detection disabled for very fast startup. This is against the RFC, but should not be a problem in most cases.
Static IP
IP address of your controller, which is used when DHCP is not available or disabled.
Static Netmask
Netmask, which is used when DHCP is not available or disabled. Default:
Static Gateway
Gateway IP address which is used when DHCP is not available or disabled.
Static DNS
DNS server, which is used when DHCP is not available or disabled.
Here you can change your MAC address. Change it only if you know what you are doing!
You may want to note it down. Sometimes it can help identifying the device in the network, i. e. routers keep track of MAC and IP address pairs.
Max. MTU
Should be 1480 by default. Change only if you know what you are doing.
More details can be found here.
HTTP-Proxy IP/Port
If you have a proxy server in your network, you can enter the IP address and port here.
Enable NTP time server. The server uses the GPS time and 1PPS as time source. It is not as accurate as other hardware dedicated to NTP, but far enough for home usage (around ~1ms). Enabled CPU sleep mode and higher load on the controller can result in much lower accuracy.


The signal encryption has been introduced in firmware 10. The "Encrypted only" setting won't allow any unencrypted signals packets. As this feature is still beta, your system might stop sending any data if something goes wrong (especially on server side). That's why we recommend to use the second option. The last option, forcing unencrypted signals shouldn't be used anymore.
More information can be found here.
Unencrypted control connection
This completely disables encrypted BORC control connection via HTTPS. Only plain HTTP will be used. Enable only in case of an error or for debugging purpose!


Enable only when you are know what you are doing! Everyone will be able to see and/or manipulate private data, like position, station id and so on.

Disable certificate verification
Don't check the TLS certificate for validity. This allows decryption of the HTTPS connection by man in the middle attackers.

Web Interface

Check it, if you don't want that others can access this web interface. You have to enter a username and password below, otherwise it won't work. We can not guarantee 100% security even with this option enabled!
We recommend to enable this option and set a username and password.


Even with this option enabled, the web interface is not 100% secure. Please don't forward the port to the internet!

Allow guest access
When checked, guests still can see the status pages (without controller id).
Port for the HTTP web server. After changing this value, you have to save your settings and reboot. Default is 80.
Default: 80, which is the standard port for http. If you change it you need to access the controller differently, i.e. with port 8080 as, http://blitzortung:8080/.
Disable webserver
Disables the webserver completely. It can only be enabled again by a factory reset or by a remote command.


This will disable the webserver completely. It can only be enabled again by a factory reset or by a remote command.


Enables the firewall. Leave it disabled if you are unsure! It will block all incoming connections except for those networks listed below. It will also block DHCP, so you should enter the IP of your DHCP server below or use a static configuration.


This is a very basic firewall. It might not work probably in case of too much requests. If the controller connects to an external IP, then this IP will be unblocked. This firewall does not check ports or protocols. You should disable DHCP and use static network configuration.

Allow IPs/Networks:
Enter the IPs or networks which should be allowed to access the web interface separated by ";". You can enter single IPs, i.e. or networks, i.e.


Detailed information about this topic can be found in the GPS section.

It is recommended to set the highest possible baud rate. This is 460800 for u-blox, 115200 for Gmm-g3/PA6H and 38400 for older ones. After changing this value, the GPS module will be reinitialized if 'No automatic init' below is unchecked.
Always init on boot
Always send init string on boot to the GPS module to be sure the correct settings are applied (GNSS, baud rate). Enabled by default since Firmware 10.
No automatic init
As soon as the controller receives 'garbage' from the GNSS module, the initialization sequence will be sent to the module. You can disable this behavior here, i.e. when you use a module which is not supported.
Enable receiving of correction data (EGNOS, WAAS). You need a good position for your antenna! If available, you can see the SBAS satellite on the status page. There's almost no advantage, so we recommend to leave this option unchecked!
Select the desired GNSS. Which constellations are working depends on your GPS module. In case of a known GNSS module/chipset unsupported combinations will be hidden.

Amplifiers 1/2


Enable Potentiometer (RED only)
Enable the manual adjustment of gain on the amplifier PCB. The green LED will be disabled and the yellow ones show the gain. The controller will still read the gain values, but does not set them.
Channel A/B/C Gain
Manually set gains. The first gain should be set higher than the second one for better signal to noise ratio. The manual gains might be lowered in case of too high amplitudes or automatic adjustments.
Start with a low gain, preferably the first of the two factors is the higher one, the second the smaller one. Increase the gain until you see a noise level of 20 to 25 mV on the Signals page.
Channel A/B/C HP (Highpass)
*High pass filter on/off depending on you needs. Note: HP on multiplies the gain by a factor of 4.
Channel A/B/C Status
With 'don't send', the particular channel won't be send to the servers, but it can be used for trigger and you can still see it in the plot. With 'Disabled', the channel will be ignored.
If you have channel without antenna, you should just set to "Disabled". If you have a channel with antenna, but it's not working, you should set it to 'Don't send'.
Channel A/B/C Threshold
The threshold values will be converted to the real threshold values for the ADC, regarding offset and channel mapping. Enter 0 to disable trigger on this channel.
As a start, you can set it two times the noise level you see on the signals page.


If several amplifier channels are mapped on one ADC, the threshold is used for all amplifier channels together or for a single channel. The maximum threshold will be used as the common ADC threshold. For RED: If you have enabled the 'Alternate Channel Mapping', then this threshold sharing is done between channels A+B of an amplifier.

Disable Noise Adaption
When noise adaption is enabled, this will disable the adaption on this particular channel.
Disable Auto Ampl. Filter
When the amplitude filter is enabled, this will disable the amplitude filter on this particular channel.


This section is only visible when the amplifier has been built with the digital filter option.

Channel A/B/C Filter
Enter the desired filter frequency. The checkbox allows enabling/disabling without changing the frequency value.

To do: Better description needed (frequency range, etc.)


A/D Converter

Leave at 500kHz. If set to 0 kHz the internal ADC sampling timing parameters can be changed.
Please leave at 500kHz for normal operation. However, you can experiment with it and carry out tests, for example to see much more details in the signals with higher sampling rates.

Maximum/Minimum Frequencies

There's an upper limit depending on how much channels are sampled. For two channels it is 2809kHz, for more than three channels it is 1405kHz. Too low sampling rate will slow down the controller on high signal rates, at the CPU has to wait for each sample until all values have been read.

Force all channels on (RED only)
When enabled, all three channels on both amplifier connectors will be enabled. In this case you should enable 'Ignore Signals Below Threshold' to limit traffic (10% is a good value).
Alternate Channel Mapping (RED only)
Instead sharing same channels of two amplifiers on the same ADC, channels A+B of a single amplifier will share the same ADC. Thus, threshold settings aren't shared between two amplifiers, but between two channels of the same amplifier. Note: It has no effect on channel C of both amps, which are always shared on one ADC.

The following settings are only visible when 'Samplerate' is set to 0 kHz. Too fast sampling can overclock the A/D converters! These settings were used in older firmware versions when we didn't have the ADC timer implemented.

Cycles p. Sample 1:
ADC clock cycles for one sample. The lower the values, the faster the sampling rate. Default is 56.
Cycles p. Sample 2:
ADC clock cycles for one sample when in 4-6 channel mode. The sampling frequency for a single channel has to be divided by 1. Default value is 28.
You always should use 12bit. Sampling rate depends also depends on this value.
Clock Divider:
Set the clock divider. Note: The default setting is 2, which gives a clock of 42Mhz. The max. speed listed in the datasheet is 36Mhz, so we have a slightly over-clocked ADC by default.
Analogue user input (RED only)

The analogue user input is an optional feature, which has nothing to do with lightning detection. When enabled, you can measure DC voltages from -3 to 30V at the measuring point. You will see them on the web-interface below CPU temperature and on the LCD on the first page. The voltage range can be changed by replacing resistors R64 and R65 with other values. You also have to change those values in the settings section on the web-interface. The default values are 10kΩ for the serial resistor Rs (R65) and 1kΩ for the RGND (R64). If you enter 0 for the RGND, then original voltage on the ADC-input pin will be shown.

Please note, that only voltages with low impedance can be measured, i.e. voltages from a power supply or from a battery. The STM32F4DISCOVERY has an additional 10k pull-up to 3V included, which cannot be changed. As the used CPU-pin is also dedicated for a special function on the STM32F4DISCOVERY, a green LED will light up there when low voltages are applied.


Use this feature at your own risk! Wrong resistor values and/or too high voltages can damage your system!

Enable User Input
You can sample a voltage, which is connected to the MP pin. Only for those who now what they are doing!
The controller uses the values to calculate the correct voltage. Solder the correct ones depending on your needs.


Tick on signal
Tick when a signal has been received (and sent).
Tick volume
Volume of the tick sound.
Beep on boot
Toggles the first beep after startup.
Beep on error
A low beep on different error conditions, like GPS, Network, Amplifier fails. If the error is gone, there's a high beep.
Beep on interference
A short deep beep when there are too much signals. The beeps are shorter than the error beeps.
Delay for interference mode
Delays the beep for interference mode. Useful when it switches on/off in short time periods. A value of 10s or more is recommended.
Beep volume
Adjust the beep volume.

LCD (RED only)

Sets the backlight brightness. Default value is 70%, so even when using wrong resistor values, the blue/amber LCDs should not get damaged. The brightness is regulated via PWM. Set to 0% or 100% to disable PWM.
Sets the contrast voltage, which is around -4V. It also depends on your supply voltage. When set to 0%, there will be no communication at all. This reduces noise spikes on very low threshold settings.
Backlight Dim
The time is measured after last push of the blue button. This function saves up to 6kWh per year for green LCD ;-) .
Auto Off
Disables LCD completely after given time after last button press. It disables all communication between controller and display.
Auto loop pages
If disabled, LCD will stay on the last button-selected page and it will always come back there even if there has been an intermediate event. The selected page will be stored in your settings when saving them.
LCD blinking on action
Blinking LCD on actions (i.e. lightning alerts)
LED off when LCD off
The users LED stay off when the LCD is off



Check voltages
Checks the 5V USB voltage and the 3V CPU voltage every second for under-/overvoltage. Disable if you get wrong values too often.
Default: Enabled
CPU Sleep
Sets the CPU to sleep mode when idle. Saves up to 40mA. Network responses could take slightly longer.
Default: Disabled
Flash Prefetch
The flash prefetch speeds up execution time, but creates some noise in the ADCs. Disable if you need higher ADC accuracy.
Leave it on for normal operation. More information can be found here.
USB Virtual COM Port
When enabled, log messages will be send through the USB connection. Windows users need a driver. NOTE: The connection gets lost during reboot. To see all messages, you have to use the serial port of the controller.
More information can be found here.
Daily Reboot
Reboot the controller at specified time. Possible values are 00:01 to 23:59. Leave empty to disable automatic reboot (recommended).
I2C Speed (RED only)
Currently for AS3935 only! Max. possible speed is 400000 Hz
Firmware Autoupdate
Automatically check for new firmware versions and install them.
An automatic upgrade has to be triggered by the server and the firmware file must have a valid signature. More information can be found here.

This feature is still beta but you should leave it enabled.



The debug options are only for debugging purpose. They can slow down your controller and may create a lot of traffic. Don't enable them if you don't know what you are doing!

Debug Tracker
Information about storing and examining the signals.
Debug Tracker Auto Adjustments
Print information about the automatic noise adaption feature.
Debug Tracker Filters
Print information about signal filters
Debug Tracker ADC
Print information about selected ADCs, thresholds etc.
Debug GPS
Prints the communication between GPS and controller. Useful on GPS problems.
Debug UDP
Prints the content of every UDP packet. This will slow down you controller dramatically!!!
Debug Signals
Some information about signal examination.
Debug Amplifiers
Prints the communication between amplifiers and controller.
Debug HTTP Remote Config
Shows data transmitted from/to control server via HTTP.
Debug HTTP Server
Shows accesses of files through the webserver.
Debug Encryption
Shows information about ciphers, certificates, RNG etc.
Debug I2C
Shows I2C debug messages (for AS3935 only).
Debug Action/Alerts
Shows debug messages from actions and alerts.
Debug Memory
Shows memory allocation.
Hide Hardfaults
Don't print information when hardfault occurred.
Syslog Server IP
IP address of the syslog server where the debug messages shall be sent to.
Due to performance reasons it is not 100% compatible to RFC 5424, but it works with most syslog servers.


An action can be triggered by a lightning alert or by other events (see next sections). The action defines which alarm sound should be played or whether an output pin should be enabled. A user defined URL can be called, which can be used for own purposes. After an action has been issued, it can be ignored for a adjustable time. An action can also be used by different events.

Desired name of the action. If empty, the action settings are not available.
Select desired sound, its volume and cycles. Depending on the sound, behaviour of cycles is different. If you set cycles to '0', then the cycle count will be higher (up to 5 times) on higher event levels (i.e. on closer lightning distance). 'Beep by level' always uses this behaviour, so cycle count is for cycling the grouped beeps. You can test the current settings with the 'Test' link, without saving them.
Ignore for
After the action has started, it will be disabled for given time.
Output (RED only)
The output will be triggered to its non default value for the given time.
The URL will be called on every action.


Lightning alerts can warn you with different actions (i.e. sounds) about approaching thunderstorms. The alerts are based on the TOA lightning data from our servers. You can specify your desired parameters like minimum distance, stroke count and time period. These values will be checked by our servers by the remote configuration feature. If the alert conditions are true, then a desired action will be issued.


Do not use these lightning alerts as the only source for protection of life or property! We can not guarantee for availability and quality of this feature! The alerts are not available when in "Monitor Mode".

Min. Strokes
Minimum stroke count and radius around your station. If count is zero, all other options are hidden.
The action which will be started when the above conditions are met.

I/O (RED only)

Some pins of the STM32F4-MCU can be used as user defined inputs or outputs.

If defined as an input, a rising and/or falling edge (configurable) can trigger an action (see 5.6.1). Additionally, an URL can be called. This URL will contain parameters with the time-stamp of the trigger derived from the GPS 1PPS timer. Thus, it is possible to use the inputs for high-precision timing measurements.

Outputs are configured in push-pull mode. Each output can drive currents up to 20mA. The summarized current of all outputs shouldn’t exceed 50mA. Please check the STM32F407 datasheet for more information! An output can be toggled by calling a dedicated URL of the web-interface. Outputs can also be triggered by actions (see 5.6.1). As an example, it is possible to let a LED blink on a lightning alerts.


This feature is for experts only! Be careful on changing settings and/or modifying your hardware! Never connect switches/buttons without series resistors to the ports! Otherwise short-circuits could destroy the MCU!

User I/O

This URL will be called when an input changes. The parameters 'pin=PPP&status=X&time=YYYYMMDDhhmmss&nsec=NNN' will be appended. PPP is the pin name, like 'PB2'. X is the status '0' or '1'. If GPS is available, the time with nanoseconds of the interrupt is appended. If not, the nsec parameter is '0'. Example:
Shows extended information on the debug console.
I/O Pins
Select the type (In or Out or Disabled), desired trigger and default state for each pin. For inputs a pullup/-down resistor can be enabled too. Outputs can be changed by calling 'http://IP-Address/index.cgi?action=output&status=X&pin=PPP'. X can be '0' for off and '1' for on. PPP is the name of the pin, like 'PB2'. No authentication is required for calling this URL!
Select an action which will be started when the port was triggered.

AS3935 (RED only)

The AS3935 is a new microchip from austriamicrosystems, which has some lightning detection technique inside. It has been designed for mobile devices, which can inform their users about regional lightning activity. The signals from lightning strokes are received by a tiny ferrite antenna, which is tuned to 500 kHz. Compared with our own powerful amplifier/controller combination, the AS3935 is very simple and cheap, but it can not be used for lightning locating. Complete PCBs with microchip and antenna are available from different distributors.

The AS3935 can be connected to our controller board via I2C bus with 5 wires. Almost every parameter can be adjusted in the web-interface. The calibration of the antenna is done automatically after boot and after each parameter change. Refer to the AS3935 datasheet for more information about the parameters. When the AS3935 detects lightning, different actions can be started, depending on lightning count and distance (see actions_and_alerts).


This feature is for experts only! Do not use the AS3935 lightning alert as the only source for protection of life or property!

AS3935 Lightning Detector

I2C Address
I2C address of the AS3935. It can take up to a minute until it appears. You can also save to flash and restart, then should appear immediately. Note: Avoid address 0x0.
Debug Messages
Prints debug messages from the AS3935. You can see them in the debug log.
Register Settings
Tune CAP
Set the correct tune capacitor value or let the auto calibration do the job for you.
Noise Floor
Threshold for the noise floor limit (Indoor/Outdoor values). Whenever the noise floor level crosses the noise threshold, the AS3935 cannot operate properly due to the high input noise received by the antenna.
Noise Auto Raise
Automatically raises the noise floor setting, if there is too much noise. This prevents, that the AS3935 stops working, if the noise floor raises suddenly. If the value has been raised, lower values will be checked from time to time. It will never go below above 'Noise Floor' setting.
Enable when using outdoor (lower gain). You should enable this checkbox even when using the module indoors, otherwise the detection rate can be very poor!
Ignore Disturber
Doesn't show disturber on the interrupt pin.
Signal Threshold
Higher thresholds lowers sensitivity for very far lightning events, with an improvement of the man-made disturber rejection as benefit. '2' is the default value by the manufacturer.
Spike Rejection
Checks the shape of the received signal. Reject the impulse signals, like spikes, picked up by the antenna. Larger values correspond to more robust disturber rejection, with a decrease of the detection efficiency. '2' is the default value by the manufacturer.
Min. Number of Lightning
Issue lightning events only if a minimum number of events have been detected in the last 15 minutes.
Min. Lightning Count / Min Distance / Action:
Enter non-zero values in these fields and choose the desired action to enable alerts for AS3935.



Upload Firmware
Upload a firmware file to flash memory, but does not overwrite current firmware. Your device won't get damaged if there's a failure during upload!
Flash Firmware
Firmware files will be verified with those on the servers by a MD5 checksum. You should only flash verified firmware files!
DFU Mode
Enter DFU mode


Signal Tools

Test Signal
Here you can enter a test signal which will be injected into the onboard amplifiers for testing the filters.
Enables sampling of the 1PPS pulse of the GPS or system voltages module with the highest possible sample rate. When 1PPS is selected, the buzzer ticks on every 1PPS pulse. Don't forget to disable this mode after you have done your tests. You can should zoom in by limiting the time (x-axis).