is it possible to have an "activity schedule"?

[jerabaul29]

We were discussing with @tnn77 and wondering: does the OLA support having an "activity schedule"? I.e. for example:

• when active, we want to measure GPS at 2 or 5 or 10Hz (one of these depending on the GPS model), and a 9dof accel gyro magnetometer output at 100Hz
• when sleeping, we want to measure nothing and just sleep

In addition, we want to have a schedule like:

• measure for 20 minutes
• sleep for 40 minutes
• loop on that schedule, creating a new file on SD card at the beginning of each measurement cycle.

Not sure, is that doable with the firmware as of today? If not, any hope a functionality like this could be added? This would be super useful in geo sciences.

[ryanneve]

@jerabaul29 I looked at this a while ago. My feeling is that the hardware certainly supports it, but the changes to the firmware would be non-trivial.
If implemented, I would suggest a schedule file with on and off times on on time and duration. Perhaps using crontab syntax? The firmware would need to be able to set alarms in the Artemis RTC for each wake time and know when to go into deep sleep for each sleep period.
This functionality would be useful for applications which only occur during certain times or on a schedule. For our application (tidal), we would probably have to upload a new schedule file every few days.

[adamgarbo]

@jerabaul29 This has been discussed before in #46. @PaulZC noted then that this type of functionality would be a major change. I suspect you'd be better off writing your own firmware.

On a side note, the schedule you've described is exactly what I've implemented in my glacier velocity project, which is based on the Artemis and MicroMod ecosystem. I've created daily, rolling or continuous logging schedules using the built-in RTC functionality of the Artemis.

[jerabaul29]

I don t think I will have time myself to re write a firmware unfortunately. But think it is a natural expansion of the OLA functionality.

[PaulZC]

Hi JR,

As reported by Adam, we have looked at this previously. The current firmware allows you to change between fast and slow logging once per day. However, as discussed previously, adding a logging schedule is a step too far. It would require completely bespoke firmware. So, with apologies, this is not something we can consider at this time.

Best wishes,
Paul

[jerabaul29]

I was thinking about this tonight, and wondering: could a possibility be to use an external timer, and have:

• the external timer decide the wake cycle (20 mins per hour or 20 mins per 3 hours or something like this)
• the AOL do the logging at full speed when getting power through the timer, and sleeping when no power through the timer
• the AOL create a new file at each power cycling

[jerabaul29]

Something based on https://www.sparkfun.com/products/15353 or similar?

If you think this could be doable, could we re-open the issue and discuss using such a hardware instead of software solution? :)

[PaulZC]

Hi JR,

You can already use Pin 11 to select between fast and slow logging. But please be aware that it is not possible to 'wake' the OLA early by changing pin 11 part way through a slow logging sleep interval. Please see #108 for details.

Best wishes,
Paul

[jerabaul29]

Thanks, that is really interesting :) . So does this well mean that we could:

• have 1) a fast logging mode that is our "true data measurement" mode
• have 2) a slow logging mode that is our "dumming logging mode corresponding to sleep"
• have an external hardware timer that make us change between the modes 1) and 2) (changes will not happen in 2) while asleep)

to hack something similar to the functionality we need?

[PaulZC]

Yes - exactly that. We added the "sleep on pin" feature in January 2021...

[jerabaul29]

Excellent! Then @tnn77 , we should be able to "hack" something by adding a piece of extra hardware :) .