Version with onboard logging

[Ryan Parle]

Has there been any thought of a version of the mySQM+ that has internal logging capability?
I am the vice chair of my local astrosoc, we are currently looking to relocate our observatory site, we have a few potential sites in consideration and i thought it might be useful to install a SQM device at each site and record data that could be used to compare the sky quality. Ideally i would like to be able to capture up to a months worth of data, so i expect an SD card would be the best option, it might also be useful to have some control over when logging is to take place, for example to use the LUX reading as a threshold to stop logging during daylight.

I also like the idea of having a hand held unit with a display, integral battery & data storage that could be used to log short samples of the sky condition on a more "adhoc" basis. this version i would probably want a little button or switch to trigger the device to record a sample.

[brownrb]

Hi Ryan
this project has a number of different choices when it comes to logging. I understand your need to evaluate various sites, but the mysqm+ was not designed with that in mind. It was designed to provide features/enhancements to an existing observatory. And, designed that one could use in a moving vechile, using gps for location, logging values to a laptop. The support for DS1307 RTC provides date/time, meaning it could be easy to extend the RTC code to set start/end times, or yes, possible to write code to monitor lux.

Inherent in that though, monitoring lux, the code would need to be robust - consider the fact of clouds, dark clouds with rain etc, sometimes the thresholds are not what they seem, and it could dark for a moment, logging starts, then the cloud goes away and it goes light, logging stops, and no doubt we would be playing ping pong around the lux state - so the code becomes large again to take into account the those things.

Option1: Run logging using the Windows App
The windows app has an autoconnect and autologging feature. The remote computer can use a task under windows to start up the windows app at any designated time.
The windows app has the ability to only log the values selected (custom log) and save these to afile at specific time intervals

Option2: TCPIP Logger and JSON Logger
Again these are applications dedicated to logging, which can query the controller using tcpip

Option 3 Web Interface
If the web service is running on the controller, this can be easily queried for controller values, and it should be relatively easy to use the json interface to query the controller periodically) Think powershell or curl to get the required data, run as a task).
For more info on curl, pg268 of PDF

Example
curl -X GET "192.168.2.128/d1 -H "accept:application/json"
will return a JSON string containing sqm, nelm, lux, skystate and cloudcover

Or you can use an XHTML call to get a specific value
Example
192.168.2.128/sq
will return the value of SQM, like 19.83

Option 4 MQTT
Set up MQTTT to publish values to a Broker - the MQTT values can be specified on the admin interface via /admin8

In terms of this question
I also like the idea of having a hand held unit with a display, integral battery & data storage that could be used to log short samples of the sky condition on a more "adhoc" basis. this version i would probably want a little button or switch to trigger the device to record a sample.

The best way to do that is use the myESP32 daughter board. You get all of the function and logging and web server etc, and could easily expand the web-server to include start-stop times for logging.

And you can use the rtc option to easily code logging to start and stop any time.

It also supports a display. So the myESP32DB with TSL2591 and OLED could easily do that,

BUT

again, there has been no effort expended to add local storage space to the controller itself,
I mean look at it this way, the thing was WiFi network support so all the logging data was designed to be up-stream.

Even if using the actual sqm meter (Unihedron), this relies on upstream devices querying the device and sending the data upstrem to be logged.

Regards
Robert