Interface a MightyOhm ionization counter to weewx

[Glenn Godden]

I would like to interface a MightyOhm ionization counter (https://mightyohm.com/blog/products/geiger-counter/ ) to weewx to report on cosmic rays, the ionization counter has both a SPI ASCII and pulse output.  Has anyone made this interface? Guidance and inputs requested. Please advise.

[Greg Troxel]

I have a MightyOhm Geiger Counter kit that I haven't built yet.

My bias in these situations is MQTT. It seems more complicated but it
lets you break the problem into small pieces that can be tested
separately, and then the geiger counter piece and the weewx piece are
totally decoupled. So steps would be (and this is my plan):

1. install mosquitto as a broker. If you skip TLS and auth because
it's your LAN it's easy. Doing it right is only a little harder.

2. Write python code to send the counts to a topic, using paho mqtt.
or pick your language, doesn't matter. Or even do something really
bogus like invoking mosquitto_pub as a shell command.

3. use mosquitto_sub to verify that the data is arriving

4. use the weewx mqttsubscribe extension to put the data into weewx

5. realize that you can also set up home assistant, and use the same
sensor via mqtt, and turn the heat onin your fallout shelter when
radiation levels increase, so it will be comfy when you go in. That's
obviously humor, but Home Assistant complements weewx and you will
want all weatherish data in both.

Step 2 isn't really that hard. I have code for ups-nut (not about
weewx) to monitor power status and am going to clean it up and publish
it.


Yes, you could write a weewx service to parse the mighty ohm data and
inject it, but with mqtt, you can keep that totally separate and you can
have the counter on a different machine in a different place.

[Glenn Godden]

Greg,

Good afternoon

Thank you for the suggest and guidance, I have implemented both a Grafana interface and also direct import into Excel from the MightyOhm ionization counter using SPI.

This was a first step in data logging, as I would like to build a 3 axis cube of ionization counters to determine approximate azimuth/elevation of cosmic rays.

: Glenn


> On Dec 22, 2021, at 12:35, Greg Troxel <g...@lexort.com> wrote:
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