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AS3935 Franklin Lightning sensor~

This feature is included only in tasmota-sensors.bin

The AS3935 is a programmable fully integrated Lightning Sensor IC that detects the presence and approach of potentially hazardous lightning activity in the vicinity and provides an estimation on the distance to the head of the storm. The embedded lightning algorithm checks the incoming signal pattern to reject the potential man-made disturbers.

Tasmota driver includes:

  • support for all AS3935 Parameters
  • support of all related commands for configuration
  • support of NF-Auto Function to auto Threshold the Noise Reduction
  • support of Auto Disturber
  • support of calibrating the internal OSC with switchable Caps



AS3935 ESP8266
VCC 3.3V


Sensor uses a software interrupt. Make sure that the connection with the IRQ pin is stable to prevent flicker.

Tasmota Settings~

In the Configuration -> Configure Module page assign:

  1. GPIOx to I2C SDA (6)
  2. GPIOy to I2C SCL (5)
  3. GPIOz to AS3935 (202)

Module Settings

After a reboot the driver will detect AS3935 automatically.

Commands and Use~

Console Commands Description values Bitlength
AS3935setnf Noise Floor Level value from 0-7 (3 Bit)
AS3935setml Minimum number of lightning 1, 5, 9, 16 (2 bit)
AS3935default load default for Sensor and Settings no argument
AS3935setgain Set Indoor/Outdoor Indoors/Outdoors (Ascii)
AS3935settunecaps Internal Tuning Cap. value from 0-15 (4 Bits)
AS3935setrej Spike rejection value from 0-15 (4 Bits)
AS3935setwdth Watchdog threshold value from 0-15 (4 Bits)
AS3935setminstage min stage that could be come with NFautotune value from 0-15: 0-7 Indoors, 8-15 Outdoors (4 Bits)
AS3935disturber Set Disturber 0/1 (1 Bit)
AS3935autonf Set Auto Tune for Noise Level 0/1 (1 Bit)
AS3935autodisturber Set Auto-Disturber 0/1 (1 Bit)
AS3935autonfmax Auto Tune with INDOOR and OUTDOOR 0/1 (1 Bit)
AS3935mqttevent mqtt messages only for lightning events 0/1 (1 Bit)
AS3935settings show all settings no argument
AS3935calibrate auto calibrate the internal Capacitors no argument
AS3935disttime time for reset Disturber in auto-mode 0-15 min. (4 Bit)
AS3935nftime time for auto-Nf treshhold 0-15 min (4 Bit)

Note for AS3935Calibrate

Normally you don't need the calibrate function. If you buy the AS3935, the module has a sticker on it with the calibrated cap. Use AS3935Settunecaps for setting up this value.

Mqtt Events:

No. Description Suppress with
0 no event
1 Lightning with Distance detected
2 Lightning out of Distance
3 Distance cannot be determined
4 Storm is Overhead
5 Noise level too high *
6 Disturber detected *
7 Irq with no Event detected

Setting table of the NF-noise sensitivity and stages:

Stages NF-LEV AFE-GB uVrms Sensitivity
Stage 0 000 Indoors 28 highly sensitive
Stage 1 001 Indoors 45
Stage 2 010 Indoors 62
Stage 3 011 Indoors 78
Stage 4 100 Indoors 95
Stage 5 101 Indoors 112
Stage 6 110 Indoors 130
Stage 7 111 Indoors 146
Stage 8 000 Outdoors 390
Stage 9 001 Outdoors 630
Stage 10 010 Outdoors 860
Stage 11 011 Outdoors 1100
Stage 12 100 Outdoors 1140
Stage 13 101 Outdoors 1570
Stage 14 110 Outdoors 1800
Stage 15 111 Outdoors 2000 less sensitive

You can find some troubleshooting tips in the Tasmota GitHub discussion .

Breakout Boards~

AS3935 AS3935 AS3935