[Feature Request] Support for Accelerometer telemetry in app

[MKBastler]

Hello dear reader,

I'm currently in process of trying to get the accelerometer in the T1000-E working for the telemetry pulls and found out that the "official" MeshCore app is not equipped to handle telemetry requests when calling addAccelerometer. While it won't interefere with the normal operation of the device (other than cutting off any subsequent telemetry calls that follow after the accelerometer one), it makes testing the implementation harder than neccessary and should probably be supported at some point. Therefore my question is: Are there any plans for implementing this? I'd greatly appreciate having support for them.
Sorry @liamcottle to tag you here, but you're likely the only person that can answer my question since the app is closed source. Thank you for your work on the app so far.

Greetings,
MK

[liamcottle]

Howdy!

Yep, I can add support for this in the next app update.
Could you please provide some sample readings from your accelerometer?

and found out that the "official" MeshCore app is not equipped to handle telemetry requests when calling addAccelerometer.

I only added support for the main LPP types that we actually used in firmware, plus some extras, but left out the more obscure ones that I wouldn't have expected to be used in the mesh.

But if accelerometer is useful to you, it's easy enough to add support for in the client.

other than cutting off any subsequent telemetry calls that follow after the accelerometer one

Yeah, this is an unfortunate thing about Cayenne LPP, it doesn't include length information for each item in the payload itself. You need to know this ahead of time. So if a client receives an LPP type it doesn't understand, it can't skip it and parse further, as it has no idea how many bytes to skip.

[seagull9000]

I've been looking at doing an implementation for trapping. A T1000e strapped to the side of a DOC200 trap as a proof of concept.

For this, high-water marks for the accelerometer would be good if they can be provided by the telemetry system.

I'll do a sensor-specific build for active notification.

[MKBastler]

Hello again,

Yep, I can add support for this in the next app update.
Could you please provide some sample readings from your accelerometer?

@liamcottle Thank you for your quick and positive response! Unfortunately, since I'm quite unfamiliar with debugging in PIO in general, I did not find a way to check the output yet and cannot provide you with real sample readings. According to the docs, Cayenne-LPP accepts Gs and the library seems to provide just that, so theoretically it should be fine (except maybe for negative values). For now, I can only provide you with a seemingly working firmware to test against. As soon as I'll find a way to get to the debug messages of a node, I'll update this response with actual values and more details.

I only added support for the main LPP types that we actually used in firmware, plus some extras, but left out the more obscure ones that I wouldn't have expected to be used in the mesh.

But if accelerometer is useful to you, it's easy enough to add support for in the client.

While I personally don't use a T1000-E (the device I use for testing is borrowed from a colleague) and therefore cannot attest of the usability of accelerometers in a meshcore node, at least @seagull9000 seems to have usecase for it. But I would only implement the basic readings here, the alert and max value logic is probably something that should be implemented in examples/simple_sensors.

Yeah, this is an unfortunate thing about Cayenne LPP, it doesn't include length information for each item in the payload itself. You need to know this ahead of time. So if a client receives an LPP type it doesn't understand, it can't skip it and parse further, as it has no idea how many bytes to skip.

Good to know that it isn't a bug in the app. Is there a list of implemented telemetry requests somewhere? Or is just all the kinds of sensors that are already implemented?

I'll do a sensor-specific build for active notification.

@seagull9000 for your information, the T1000 (like most nrf52-based boards) doesn't currently have a sensor build defined in its plattformio.ini yet, if you want custom sensors thats probably where you'll need to start out.

For documentations sake, here are some things about the implementation:
There is unfortunately no library in the Arduino Library Manager that can control the QMA6100P accelerometer found in the T1000-E and very little info on T-1000 pins and schematics, most of which is here. I have to use a direct zip-Import from a library of the other mesh. This library only required a missing #include <stdint.h> for it to work and compiles fine when implemented into the EnvironmentSensorManager. If this implementation makes it to a PR, I'll fork the library with the fix since there's been no commits for 2 years now.