AS3935 library errors?

Sensors Distance
1

Seems to me that the code for getting the lighting energy value is in error.

First off the bottom 5 bits of MMSBYTE are masked with 0xF using the constant ENERGY_MASK, but should be 0x1F to get 5 bits.

Second these bits should only be shifted up 8 bits in the long variable _purelight the first time, not 16 as coded. They will eventually be shifted the correct 16 bits by the second 8 bit shift.

2

Hello!

I’m the engineer that wrote the library and at first glance I can confirm these issues with the library. I have not implemented a fix just yet but have filed an issue here on Github:

https://github.com/sparkfun/SparkFun_AS … /issues/14

I’ll respond here again when the issue is fixed in the next few days.

3

Thanks.

These are not errors, but suggestions:

  1. The chip allows the AFE Gain to be set to values other than just INDOOR and OUTDOOR. At the moment I’m not sure of the valid upper range, but I notice you only allow the two values INDOOR and OUTDOOR. It might be useful to just take the value screening out of the setIndoorOutdoor function to allow more continuous settings.

  2. This is probably a typo in the data sheet, but in the Interrupt Management section it says the chip might issue an interrupt with register =000 when the distance estimation changes. So in addition to noise, disturber, and lightning; there might be a fourth type interrupt. I’ve never actually seen it so far, but I have seen 0010 but don’t know what it indicates.

4

Thanks for the suggestions, I’ll add that into my list of things to take a look at. I’m a bit busy so I won’t get a chance to look at these anytime soon. If you’re feeling like it, a pull request would help me greatly. Otherwise the mistake in your original post has been corrected.

5

Thanks.

Just to follow up:

There is definitely a type 0 interrupt! It generally occurs after a storm has passed. It represents an update to the distance but not the result of a lightning strike.

The best way to handle adding more variable AFE gain would be to create a separate function and leave setIndoorOutdoor as is.