AMS AS3935 Franklin Lightning Sensor

The as3935 sensor platform allows you to use your as3935 sensor (AliExpress, AMS_AS3935) in order to get notified when a thunderstorm is getting close.

The AS3935 can detect the presence of lightning activity and provide an estimation on the distance to the head of the storm. The chip issues a notification through an interrupt pin.

The AS3935 can be configured to use either the SPI or I2C protocol for data communication. First choose which communication method you want to use for the sensor, set the SI pin for the appropriate level and set up the esphome integration for the chosen communication method.

Module Pins

Module Pin Description
VCC/VDD Positive supply voltage
GND Ground
SCL I²C clock bus or SPI clock bus (according to SI setting)
MOSI I²C data bus or SPI data input bus (according to SI setting)
MISO SPI data output bus
CS Chip Select (active low)
SI Select Interface (GND → SPI or VDD → I²C)
IRQ Interrupt (out)
EN_V Voltage Regulator Enable
A0 I²C address selection LSB
A1 I²C address selection MSB
../../_images/as3935.jpg

AS3935 Lightning Sensor.

# Example configuration for SPI (decide for one!)
as3935_spi:
  cs_pin: GPIO12
  irq_pin: GPIO13
# Example configuration for I2C (decide for one!)
as3935_i2c:
  irq_pin: GPIO12

# Example configuration for creating sensors
sensor:
  - platform: as3935
    lightning_energy:
      name: "Lightning Energy"
    distance:
      name: "Distance Storm"
binary_sensor:
  - platform: as3935
    name: "Storm Alert"

Configuration variables (shared):

  • irq_pin (Required, Pin): The IRQ pin, which indicates if a lightning strike has been detected.
  • indoor (Optional, boolean): Indicates if the sensor is used indoor. Defaults to true.
  • noise_level (Optional, integer): Noise floor level is compared to known reference voltage. If this level is exceeded the chip will issue an interrupt to the IRQ pin, broadcasting that it can not operate properly due to noise (INT_NH). Defaults to 2.
  • spike_rejection (Optional, integer): Helps to differentiate between real events and actual lightning. Increasing this value increases robustness at the cost of sensitivity to distant events. Defaults to 2.
  • lightning_threshold (Optional, integer): The number of lightnings that must appear in a 15-minute time window before a lightning storm is detected. 15 minutes is the window of time before the number of detected lightning events is reset. The number of lightning strikes can be set to 1,5,9, or 16. Defaults to 1.
  • mask_disturber (Optional, boolean): This setting will return whether or not disturbers trigger the IRQ Pin. Defaults to false.
  • div_ratio (Optional, integer): The antenna is designed to resonate at 500kHz and so can be tuned with the following setting. The accuracy of the antenna must be within 3.5 percent of that value for proper signal validation and distance estimation. Defaults to 0.
  • capacitance (Optional, integer): This setting will add capacitance to the series RLC antenna on the product to help tune its resonance. The datasheet specifies being within 3.5 percent of 500kHz to get optimal lightning detection and distance sensing. It’s possible to add up to 120pF in steps of 8pF to the antenna. Defaults to 0.
  • watchdog_threshold (Optional, integer): Determines the threshold for events that trigger the IRQ pin. Defaults to 2.

Sensor entries:

  • lightning_energy (Optional): Lightning energy value. According to the datasheet this is only a pure value that doesn’t have any physical meaning.
    • name (Required, string): The name for the lightning energy sensor.
    • id (Optional, ID): Set the ID of this sensor for use in lambdas.
    • All other options from Sensor.
  • distance (Optional): Distance in km to the front of the storm and not the distance to a lightning strike.
    • name (Required, string): The name for the distance sensor.
    • id (Optional, ID): Set the ID of this sensor for use in lambdas.
    • All other options from Sensor.
  • binary sensor (Optional): Binary sensor that indicates if a lightning strike was detected.
    • name (Required, string): The name of the binary sensor.
    • id (Optional, ID): Manually specify the ID used for code generation.
    • All other options from Binary Sensor.

Configuration variables (i^2c):

Use this if you want to use your AS3935 in i^2c mode.

# Example configuration for I2C (decide for one!)
as3935_i2c:
  irq_pin: GPIO12
# Example shared configuration
sensor:
  - platform: as3935
    lightning_energy:
      name: "Lightning Energy"
    distance:
      name: "Distance Storm"
binary_sensor:
  - platform: as3935
    name: "Storm Alert"
  • address (Optional, int): Manually specify the i^2c address of the sensor. Defaults to 0x03 (A0` and ``A1 pins pulled low). Another address can be 0x02.

Configuration variables (spi):

Use this if you want to use your AS3935 in SPI mode.

# Example configuration for SPI (decide for one!)
as3935_spi:
  cs_pin: GPIO12
  irq_pin: GPIO13
# Example lightning and energy sensor
sensor:
  - platform: as3935
    lightning_energy:
      name: "Lightning Energy"
    distance:
      name: "Distance Storm"
binary_sensor:
  - platform: as3935
    name: "Storm Alert"
  • cs_pin (Required, Pin Schema): The chip select pin.