support for AS3935, initial commit

[device111]

Description:

Support for AS3935 Lightning Sensor added:

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

Datasheet available at: https://www.mouser.com/datasheet/2/588/ams_AS3935_Datasheet_EN_v5-1214568.pdf

supported commands and functions:

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 Inddoor/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)

notice for the as3935calibrate:
normaly you don't need the calibrate function. If you buy the AS3935, the Modul has a sticker on it with the calibrated cap.
Use the "as3935settunecaps" for setting up this value.

notice for the IRQ Pin:
the sensor uses a software interrupt.
Make sure, that the connections with the IRQ pin are stable to prevent flicker.

Mqtt Events:

nr.	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

the Modul need 5k4 of flash memory. By default, this module is not activated.
you must set "USE_AS3935" to compile this module.

Tasmota settings:

Related issue (if applicable): fixes #

Checklist:

• The pull request is done against the latest dev branch
  • Only relevant files were touched
  • Only one feature/fix was added per PR.
  • The code change is tested and works on core Tasmota_core_stage
  • The code change pass travis tests. Your PR cannot be merged unless tests pass
  • I accept the CLA.

[s-hadinger]

Theo, should it be activated by default?

[device111]

oh, sorry...forgott to deactivate after testing...

[s-hadinger]

Wow great job and super clean code!

[device111]

thanks! it was also a lot of work..:-)

[device111]

and that I don't forget it, a big thanks to @ludwich66 for testing and give a lot of ideas!

[blakadder]

@device111 please review https://tasmota.github.io/docs/AS3935/ . Hope the wiring is correct, I was deducing from what you wrote

[TimelessNL]

Great work so far! ⚡

I had this sensor for quite some time now (collecting dust in my desk)
But now I have a reason to finally attach the sensor to a Wemos D1 Mini Pro (on its 3v3 supply). But I got some trouble calibrating the sensor, it's constantly outputting Disturber detected and Storm is Overhead while there clearly isn't. I've been trying to do some calibration guesses but they won't survive a reboot. When I set AS3935setgain Outdoors after a reboot it's back to Indoors.

normaly you don't need the calibrate function. If you buy the AS3935, the Modul has a sticker on it with the calibrated cap.

a sticker on it? There is a sticker on the coil but this seems to be identical on all modules? Maybe my module is missing the factory calibration sticker somehow.

I also noticed that listening has some unnecessary comma's, or is this as designed?

Is this an instability issue?

This is my setup (Wemos D1 Mini Pro with DS18B20/BME280/AS3935):

Using these pinouts:

[ludwich66]

I see there is a localisation problem, I use dots as decimal separator and comma 1,000.00 vs 1.000,00 (German Interface) —> listening … vs. listening ,,,

…

Am 15.05.2020 um 00:16 schrieb TimelessNL ***@***.***>: Great work so far! ⚡ I had this sensor for quite some time now (collecting dust in my desk) But now I have a reason to finally attach the sensor to a Wemos D1 Mini Pro (on its 3v3 supply). But I got some trouble calibrating the sensor, it's constantly outputting Disturber detected and Storm is Overhead while there clearly isn't. I've been trying to do some calibration guesses but they won't survive a reboot. When I set AS3935setgain Outdoors after a reboot it's back to Indoors. normaly you don't need the calibrate function. If you buy the AS3935, the Modul has a sticker on it with the calibrated cap. a sticker? There is a sticker on the coil but this seems to be identical on all modules? Maybe my module is missing the factory calibration sticker somehow. I also noticed that listening has some unnecessary comma's, or is this as designed? <https://user-images.githubusercontent.com/10838968/81990544-ac893280-963f-11ea-8af8-e47b916c8ecc.JPG> Is this an instability issue? <https://user-images.githubusercontent.com/10838968/81990578-b90d8b00-963f-11ea-8f8e-55108fecd5bd.JPG> This is my setup (Wemos D1 Mini Pro with DS18B20/BME280/AS3935): <https://user-images.githubusercontent.com/10838968/81990598-be6ad580-963f-11ea-8adc-cfbd75cf3c47.jpg> — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#8130 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC5DF3LGHGH355RZVVHRI7TRRRUVDANCNFSM4MF4TZVQ>.

[TimelessNL]

Ah! That does make sense. But 'listening...' is set using a define, why are the dots replaced by comma's?

Ludwich you tested this implementation right? Did you have any problems with saving the calibration settings?

[ludwich66]

I have a topic in mind here. The capacitors on your board are too big or too small, outside the area - not in the middle of the adjustment area. Can you measure the cap? 680+270 pF I use a logic analycer to check the Frequency There are 16 software configurable Caps to trim the Frequency 4 is the nearest value to generate 500khz 31,25 kHz Clock * Divider 16 == 500Khz ASM3935 Reference Design This is the normal calibration on my board 01:13:05 CMD: AS3935CALIBRATE 01:13:08 MQT: stat/AS3935_DEAA8F/RESULT = {"AS3935":{"Cap gesetzt auf:":4}} 01:13:15 MQT: tele/AS3935_DEAA8F/SENSOR = {"Time":"2020-05-15T01:13:15","MAX44009":{"Illuminance": 0.000},"AS3935":{"Event":2,"Distance":0,"Energy":0,"Stage":0}}

[device111]

@TimelessNL
do you have set the option "as3935autonf"?
If you set this option, the gain will always start on "INDOOR".

can you make a "as3935settings" and report the result?

And yes, i have read on an Amazon report, thtat this modul has the wrong caps on it.
you can read it in german, if you search "as3935" and the user "Hotzenplotz94".
He talk about wrong caps on the pcb and he don't can adjust the antenna calibration.

[ludwich66]

There are 16 steps of sensifity They are coupled with „AS3935autonf“ 1 or 0 If you set AS3935autonf to 0, you can set Indoors(AS3935setgain) and (AS3935setnf) fix the algorythmus changes the sensityfity (less noise and less disturber -made it more sensitive —> Rang ist higher > 40000m) Find the right conditions for your place AS3935setnf 0,1,2,3,4,5,6,7 AS3935autonf 0,1 AS3935setgain Indoors, Outdoors Indoors Outdoors 0,1,2,3,4,5,6,7 0,1,2,3,4,5,6,7 0,1,2,3,4,5,6,7 8,9,10,11,12,13,14,15 (Stage) This are my local setting: 11:24:59 CMD: as3935settings 11:24:59 MQT: stat/AS3935_DEAA8F/RESULT = {"AS3935":{"Gain":"Indoors","NFfloor":0,"uVrms":28,"Tunecaps":4,"MinNumLight":1,"Rejektion":2,"Wdthreshold":2,"MinNFstage":0,"NFAutoTime":4,"DisturberAutoTime":1,"Disturber":"Off","NFauto":"On","Disturberauto":"On","NFautomax":"On","Mqttlightevent":"Off"}}

[TimelessNL]

@TimelessNL
do you have set the option "as3935autonf"?
If you set this option, the gain will always start on "INDOOR".

Yes I did, and indeed when I restart Tasmota the gain indeed goes up (to around 6 after a while). Sorry I didn't notice, I was only looking at Indoors/Outdoors. And when I set as3935autonf 0 the calibration does survive a reboot.

But what does as3935autonfmax do? The description: "Auto Tune with INDOOR and OUTDOOR" is a bit cryptic, does it mean that as3935autonfmax 0 limits the stages to only indoors?

can you make a "as3935settings" and report the result?

19:52:37 CMD: as3935settings
19:52:37 MQT: stat/sonoff/RESULT = {"AS3935":{"Gain":"Indoors","NFfloor":6,"uVrms":130,"Tunecaps":15,"MinNumLight":1,"Rejektion":2,"Wdthreshold":2,"MinNFstage":0,"NFAutoTime":4,"DisturberAutoTime":1,"Disturber":"On","NFauto":"On","Disturberauto":"On","NFautomax":"On","Mqttlightevent":"On"}}

And yes, i have read on an Amazon report, thtat this modul has the wrong caps on it.
you can read it in german, if you search "as3935" and the user "Hotzenplotz94".
He talk about wrong caps on the pcb and he don't can adjust the antenna calibration.

I've found the review, and this indeed seems unfortunate 😢, I've bought this module a while ago, but never took the time to write some code for it. Until I saw this change-set and was happily surprised by the ease of use.
mY module may have the wrong caps but I have the small PCB not the bigger one Hotzenplotz94 is writing about on amazon. So maybe that makes a difference

(this is my sensor)

I have a topic in mind here. The capacitors on your board are too big or too small, outside the area - not in the middle of the adjustment area. Can you measure the cap?

To reliably measure the capacitance I have to remove the capacitor from the board, I prefer not to do that until I have some replacements. Maybe I can order some correct capacitors so I can replace them anyway. I have mounted the sensor on the roof today. So when the first summer thunderstorm arrives I can test if this sensor 'hears' anything.

I've set as3935autonf 1 and with a clear sky there is no disturbance detected or Storm is Overhead but it is listening,,, as it should. Maybe last time I tested there where some disturbance's within 40Km, but I simple didn't notice since it was night :)

[ludwich66]

I tried to set as3935setnf to 0 after this setting i do calibrate no automatic reset follows did you help this info? 17-05-2020 13:59:51 CMD: as3935setnf 0 13:59:51 MQT: stat/AS3935_DEAA8F/RESULT = {"AS3935":{"setnf":0}} 14:00:09 CMD: as3935calibrate 14:00:12 MQT: stat/AS3935_DEAA8F/RESULT = {"AS3935":{"Cap gesetzt auf:":4}} 14:00:20 MQT: tele/AS3935_DEAA8F/SENSOR = {"Time":"2020-05-17T14:00:20","MAX44009":{"Illuminance": 2154},"AS3935":{"Event":5,"Distance":0,"Energy":0,"Stage":1}} ludwich

[TimelessNL]

@ludwich66 your posts are very hard to read because you're replying to a github mail. And could you please try to use markdown to make them easier to read?

[device111]

And when I set as3935autonf 0 the calibration does survive a reboot.

If you set as3935autonf to 1, do you have also reboots?
Did you have always reboots with calibrating?

But what does as3935autonfmax do? The description: "Auto Tune with INDOOR and OUTDOOR" is a bit cryptic, does it mean that as3935autonfmax 0 limits the stages to only indoors?

If "as3935autonfmax" is Enabled, the AutoNF Funktion goes over both Areas (Indoor and Outdoor).
If disabled, the AutoNF goes about the Floor that you have set with "as3935setgain". (Indoor or Outdoor)

and "as3935setminstage" is combined with Autonf:
this the limit for the minimum stages you can come. (highly sensitive).
It makes no sense to go up in sensitivity if there is a lot of Base-Noise anyway.

[TimelessNL]

If you set as3935autonf to 1, do you have also reboots?

Yeah I disabled flash writes, when I determent a config is correct I reboot Tasmota to make those changes permanent.

If "as3935autonfmax" is Enabled, the AutoNF Funktion goes over both Areas (Indoor and Outdoor).
If disabled, the AutoNF goes about the Floor that you have set with "as3935setgain". (Indoor or Outdoor)

Ah that makes sense, I've tried this and indeed it does what it is suppose to do.

and "as3935setminstage" is combined with Autonf:
this the limit for the minimum stages you can come. (highly sensitive).
It makes no sense to go up in sensitivity if there is a lot of Base-Noise anyway.

But when I set this to as3935setminstage 6 it still starts at stage 0 after a reboot, shouldn't this then start at stage 6?

Last few days AutoNF detected noise until it hit stage 6 and then became stable and started listening... we did finally receive some heavy clouds today, which can carry some high altitude thunder (not very close though) and the AS3935 started to give some output. But these seem like false-positives to me because it was giving lightning overhead within 1KM so I raised it to stage 9 and then the range went to 5KM which may be plausible, it stopped when I raised it to stage 15 after which it went back to listening.... Still finding it strange that AutoNF does not make the sensor reliably detect thunder though.

I also get allot of Interrupt with no event messages during those heavy clouds.

These are my current settings:

22:17:43 CMD: AS3935settings
22:17:43 MQT: stat/sonoff/RESULT = {"AS3935":{"Gain":"Outdoors","NFfloor":1,"uVrms":630,"Tunecaps":15,"MinNumLight":1,"Rejektion":5,"Wdthreshold":2,"MinNFstage":6,"NFAutoTime":4,"DisturberAutoTime":1,"Disturber":"On","NFauto":"Off","Disturberauto":"On","NFautomax":"On","Mqttlightevent":"On"}}

[device111]

i think, you have a problem with your sensor. if you can not adjust right now with the calibrate function, it does not work.
you can contact @ludwich66 . He have a sensor and can you explain the settings.
On youtube gives a realy good viedo about adjusting the as 3935. the Sensor have a lot of settings, that you can change.

[device111]

@TimelessNL
Now, the initial Settings for as3935setminstage is correct. the changes are now in developement.

[TimelessNL]

i think, you have a problem with your sensor

That is very unfortunate, since most sensors that can be bought from Ebay or Aliexpress are those purple color PCBs that most likely have wrong spec capacitors on them like you suggested.

Now, the initial Settings for as3935setminstage is correct.

Great, thanks!

I've not tried to integrate this sensor in Domoticz yet so I do not have any real statistics, but what I've been thinking: yes the sensor does indicate lightning yet nothing can be seen by the naked eye, but what if the energy levels are much higher during visible thunder and the sensor is now only announcing some static electricity in the atmosphere.

There is probably no easy way to use the build-in Domoticz configuration to send the appropriate information to Domoticz I guess?

EDIT:
I've added this rule, but I'm not sure if the AS3935 supports tele- massages?
Rule1 ON Tele-AS3935#Distance DO publish domoticz/in {"idx":x,"svalue":"%value%"} ENDON ON Tele-AS3935#Energy DO publish domoticz/in {"idx":x,"svalue":"%value%"} ENDON
It does send the values to Domoticz, but even when the web-interface shows noise detected the information in the tele- message is "AS3935":{"Event":0,"Distance":0,"Energy":0}. This should have been "AS3935":{"Event":5,"Distance":0,"Energy":0} I guess.

[HelmiBeh]

Hello, I have a problem with the calibration procedure: as a result I got {"calibration failed":12}. So I changed the caps to the needed value (680p and 270p). But i got the same result, also if I changed them to 680p and 220p. It would be nice, if the calibration routine could output the error value of the 16 steps, so one can determine, if the cap is too large or too small.

[Maddinthebrain]

i think, you have a problem with your sensor. if you can not adjust right now with the calibrate function, it does not work.
you can contact @ludwich66 . He have a sensor and can you explain the settings.
On youtube gives a realy good viedo about adjusting the as 3935. the Sensor have a lot of settings, that you can change.

@device111 Which video do you mean? Is it this one: https://www.youtube.com/watch?v=fTEEDfWbGEU?

[device111]

Yes!

[Birthon]

Hi, I'm trying to get a GY AS3935 working without success. The system detects noise and disturbances but definitely does not detect lightning. What could be happening.

[ludwich66]

Hi, I'm trying to get a GY AS3935 working without success. The system detects noise and disturbances but definitely does not detect lightning. What could be happening.

Hi Birthon,
Please post first your settings:
Konsole: "as3935settings"

Works "as3935calibrate" fine? (There are Boards with wrong capacitance Values)

ludwich

[Birthon]

Hi Ludwich,
I have used this settings in a board Feather MO adalogger

I'm developing a tricorder project that contains several different sensors. The code is too big to put in here. However, the basic sketch for AS3935 was the one placed below. This was the only sketch that adapted to the rest of my code and did not offer incompatibility with other libraries. As I said before, the system detects triggering of tasers, electrical welding, short circuits, but it does not detect lightning.
I've used AS3935 before on other projects and I've never had any problems, although I've never used this basic sketch before. Can you give me any tips to investigate this issue?
How does the calibration process work?
Thank you for any help.

`/*

This example demonstrates how to detect lightning! It has a few basic
settings to help with rejecting noise or "disturbers" (false lightning events).
It uses the onboard interrupt hardware pin, so in addition to attaching to
it data lines you'll need to connnect to the interrupt pin labled "INT".

By: Elias Santistevan
SparkFun Electronics
Date: May, 2019
License: This code is public domain but you buy me a beer if you use this and we meet someday (Beerware license).

*/

#include <SPI.h>
#include <Wire.h>
#include "SparkFun_AS3935.h"

// 0x03 is default, but the address can also be 0x02, 0x01.
// Adjust the address jumpers on the underside of the product.
#define AS3935_ADDR 0x03
#define INDOOR 0x12
#define OUTDOOR 0xE
#define LIGHTNING_INT 0x08
#define DISTURBER_INT 0x04
#define NOISE_INT 0x01

SparkFun_AS3935 lightning(AS3935_ADDR);

// Interrupt pin for lightning detection
const int lightningInt = 4;

// This variable holds the number representing the lightning or non-lightning
// event issued by the lightning detector.
int intVal = 0;
int noise = 2; // Value between 1-7
int disturber = 2; // Value between 1-10

void setup()
{
// When lightning is detected the interrupt pin goes HIGH.
pinMode(lightningInt, INPUT);

Serial.begin(115200);
Serial.println("AS3935 Franklin Lightning Detector");

Wire.begin(); // Begin Wire before lightning sensor.

if( !lightning.begin() ) { // Initialize the sensor.
Serial.println ("Lightning Detector did not start up, freezing!");
while(1);
}
else
Serial.println("Schmow-ZoW, Lightning Detector Ready!");

// The lightning detector defaults to an indoor setting at
// the cost of less sensitivity, if you plan on using this outdoors
// uncomment the following line:
//lightning.setIndoorOutdoor(OUTDOOR);
}

void loop()
{
if(digitalRead(lightningInt) == HIGH){
// Hardware has alerted us to an event, now we read the interrupt register
// to see exactly what it is.
intVal = lightning.readInterruptReg();
if(intVal == NOISE_INT){
Serial.println("Noise.");
// Too much noise? Uncomment the code below, a higher number means better
// noise rejection.
//lightning.setNoiseLevel(setNoiseLevel);
}
else if(intVal == DISTURBER_INT){
Serial.println("Disturber.");
// Too many disturbers? Uncomment the code below, a higher number means better
// disturber rejection.
//lightning.watchdogThreshold(threshVal);
}
else if(intVal == LIGHTNING_INT){
Serial.println("Lightning Strike Detected!");
// Lightning! Now how far away is it? Distance estimation takes into
// account any previously seen events in the last 15 seconds.
byte distance = lightning.distanceToStorm();
Serial.print("Approximately: ");
Serial.print(distance);
Serial.println("km away!");
}
}
delay(100); // Slow it down.
}
`

[sfromis]

FTR, connecting/configuring AS3935 to another ESP32 device, I got the sensor detected and active as in providing data on Tasmota front page and in MQTT messages.

[barbudor]

@rb2k I suggest that to open a new discussion detailing:

• which binary you are using as per BUILDs this is available only in tasmota32 and tasmota-sensors
• if you have enabled the driver with i2cdriver48 1

[ludwich66]

I am using a

Working on a selfcompiled Tasmota 12.0.2.2 Version.
HW:
ESP8266
Mod 1016 Module
Difference of 15 cm between Sensor and ESP-Module

See Tests:
#8130 (comment)

Work stable for me since first implementation.

I'm happy to help if I get concrete ideas.

ludwich

[rb2k]

@rb2k I suggest that to open a new discussion detailing:

• which binary you are using as per BUILDs this is available only in tasmota32 and tasmota-sensors
• if you have enabled the driver with i2cdriver48 1

Ok, makes sense! I put it up over here: #16263

[vidalpascual]

Yes the wiring is from these dokument, i have a CJMCU.

The sensor has worked with this : https://github.com/shred/kaminari

Then i have changed to Tasmota, better for use at me with the mqtt

And this wil not work

Have you had success with Tasmota? I have the same CJMCU and is not working...

[barbudor]

Have you read the discussion #16400 ?

[device111]

What is not working?
Do you know, that the https://github.com/shred/kaminari Projekt work with SPI? You must wire the sensor correct.
read the discussion that barbudor mentiod..

[device111]

and I,m not sure if the wiring in Tasomta Docs are right for the CJMCU. I have made the Descripton for the CJMCU from another side. I have found anothe Wiring for I2C. The EN_V here is connected to GND and not to VCC.
And you must connect the A0 and A1 to VCC to have the right I2C Address.

Can you test this wiring. If it works, i must change the Docs.

[device111]

ok, i have corrected the Schematic in the Docs. The one should working:

[ludwich66]

PIN 15 (AS3935) = ADD0 = A0
PIN 16 (AS3935) = ADD1 = A1
I see 2 x 10KΩ to GND as Preset on this Picture

L

SET I2C Adress:
The device addresses for the AS3935 in read or write mode are defined by:
0-0-0-0-0-a1-a0-0: write mode device address (DW)
0-0-0-0-0-a1-a0-1: read mode device address (DR)
Where a0 and a1 are defined by the pins 5 (ADD0) and 6 (ADD1).

[device111]

ok, then normaly should work without wiring to VCC. The Datasheet says "Connect to GND or VCC".
Let's give it a try..

[device111]

you are right...

this circuit diagram even shows the wrong capacitors of the antenna...:-)

[barbudor]

so if not needed, please cancel your PR

[vidalpascual]

What is not working?
Do you know, that the https://github.com/shred/kaminari Projekt work with SPI? You must wire the sensor correct.
read the discussion that barbudor mentiod..

SPI wiring and that project works, but I2C wiring and Tasmota not.

[device111]

Do you wire to an ESP32 or ESP8266?
Have you tried this wiring?

[vidalpascual]

Do you wire to an ESP32 or ESP8266? Have you tried this wiring?

Yes, I tested that wiring with Tasmota and the AS3935 is not recognised.

I'am testing with a Wemos D1 mini that has an ESP8266.

[HelmiBeh]

There is an error at all of the wiring pictures: MISO is an output of the chip, so it shouldn't be connected to ground!

[sfromis]

As the Tasmota driver for the AS3935 expects to use I2C communication (selected with connecting the SI pin to 3.3V), instead of SPI, the pins used for communication are SCL and the MOSI pin used as SDA. Hence MISO is not part of the communication, and it may not be important what you do with it. I'd assume that connecting it to GND is fine.

[HelmiBeh]

Don't agree with You. As data sheet says, MISO is an output, it's not good in any circumstances to short it with ground. You don't know, which voltage is put out in that case. If not used, let it left open!

[sfromis]

Well, "output" does not mean always outputting, the data sheet suggests that MISO is set to tristate if not active. And my AS3935 board has solder jumpers for connecting MISO and CS to GND, supposedly for a reason.

With MISO connected to GND, I'm getting I2C: AS3935 found at 0x03 at boot, and a lot of "noise" reading like "AS3935":{"Event":5,"Distance":0,"Energy":0,"Stage":7} in the sensor payloads.

[barbudor]

Figure 19 page 15

[sfromis]

If someone wonders, that refers to the data sheet linked in the first post here, which clearly shows that the solder jumpers on my board are there for a good reason.

[device111]

I have now found another data sheet for the MOD-1016 breakout board with the AS3935 on it.
(I'm not sure but I think the MOD-1016 board was the one I did my testing with).

Strangely enough, there is other information here about wiring with I2C.

The manufacturer's original data sheet for the AS3935 states that with I2C wiring the CS and MISO should be connected to ground. (Figure 19 page 15).

The MOD-1016 Datasheet states:

1. the CS pin should NOT be connected to ground. (page 5)
2. In addition, the AS 3935 probably has a firmware bug. The I2C address cannot be 0x00 (broadcast). (page 4)
3. Also, in the MOD-1016 schematic, the MISO pin is not connected to anywhere. (Page 7)
4. The next difference is that AMS has corrected the data sheet with Rev. 1.01 and you should now set the address pins to VREG and not to VCC when the voltage regulator is activated. I don't know whether these changes have been implemented in all available breakout-boards.

Maybe @ludwich66 can write here which module he used. This also seems to work perfectly.
Edit: Ok, Ludwich66 use a MOD1016 Board, as he wrote above.
Question: Have you shorted the CS-GND solder-pad?

MOD1016 Datasheet:
MOD-1016_hw_v8_doc_v4.pdf

actual AS3935 Datasheet v1.04:
AS3935-Datasheet_104.pdf

[sfromis]

Reading that, I do not see any requirement to remove the CS/GND solder jumper, except if you want to use SPI instead of I2C. And while MISO/GND is not stipulated, it is not suggesting "should not be connected", merely that it is not used. Thus, not importantly different from existing suggestions around those two pins, having both to GND should still be fine for I2C usage.

Of course, not using I2C Address 0x00 may be useful; however Tasmota already expects address 0x03.

(ludwich66 has not been posting here for two years now).

[device111]

I think, it's not so easy with the CS Pin.

the MOD1016 datasheet says:

"Also, you will need to remove the solder jumper that keeps CS pulled to ground for
I2C use. In many devices, the use of CS is optional and allows the microcontroller to
talk to different devices on the one buss. However, in the case of the AS3935, you
will need access to CS since it forms part of the protocol (CS returning high triggers
the AS3935 to execute the command it was given). "

I can't imagine that this has an influence on the internal behavior of the AS3935, but apparently it does.

However, the MOD1016 Modul is working for me. I have a look tomorrow on my Modul, if i have shorted the CS-GND Pad.

[sfromis]

Yes, I did read that, in the clear context of To use the module with SPI communications

As we are not talking about SPI but I2C, I'd simply disregard that obvious warning about not having CS grounded for SPI operation.

[device111]

ahhhh...ok. Thanks sfromis!
Now i understand the english sentenence! I should improve my english knowledge... 😄 😃

[ludwich66]

Ludwig lebt!
ludwich is alive!
I have the MOD-1016 running in my design.
Only 5 wires are wired, the rest is in its original state.
(GND, VCC, SCK, SDA, IRQ) (+ferrite core)
The whole thing has been running for quite some time without any problems.

[device111]

wow, great setup!

[HelmiBeh]

@ludwich66: really nice setup!
I use two different boards: GY-AS3935, which doesn't need any connection on SI and CS. MISO is also open. The other is CJMCU-3935, which needs SI high and CS low. MISO is again open. Supply voltage in both cases is 3V3.