A few asset tracker questions

[billywalton]

Hi all,

Just have a few Asset tracker questions if anyone knows the answer:

1) If using the nRF Cloud, and a custom env_sensor, what's the maximum length databuf that can be posted in one go?

struct cloud_data {
    char *buf;
    size_t len;
};

2) If a cloud post fails because it can't connect or no signal, does it queue the data for retry or just drops it?

3) Is it using the SAADC to monitor the battery anywhere?

Thanks in advance for any help

Billy

[JONATHAN LL]

What Asset tracker version are you looking at ?

Assetracker
or
Assetracker V2

Regards,
Jonathan

[billywalton]

Hi,

The first version is the one I have running, but could change if needed

[JONATHAN LL]

There are some improvements in V2 that we do recommend and in theory it is easier to implement custom use cases as the design is more modular.

That said 

If using the nRF Cloud, and a custom env_sensor, what's the maximum length databuf that can be posted in one go?

the data buffer can be adjusted, but for one transmit 10K with dynamically allocated date by sending pointer + length. you can allocate heap or stack. 

If a cloud post fails because it can't connect or no signal, does it queue the data for retry or just drops it?

 Data is being buffered and will be uploaded in correct order, however there is a limit to the amount of data that can be stored
 https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/asset_tracker_v2/README.html#data-buffers 

Is it using the SAADC to monitor the battery anywhere?

No, not in any of the examples at the moment.
In the cat tracker -> there is a get_voltage_levelf function.  And the way its done in Asset tracker V2 is request data from modem. 

Regards,
Jonathan

[billywalton]

Firstly, thanks for this, a really informative post.

I have tried V2 but have problems with the AWS, the AWS part is a massive headache for this project

My client's requirement is to sample 8 channels of ADC at a variable rate, maximum 10Hz, As low power as possible.

So, assuming 2 bytes per sample, 1.6K every 10 secs or 9.6K every minute

If the LTE signal is lost, then I have to store the data until I can get a connection and upload it (am fitting the SDCARD for this I guess)

I like the provisioning and FOTA offered by nRFCloud, its neat, clean and easy to implement

But the sampled data does not necessarily need to pass through the cloud (as I read somewhere there is a 1M transaction limit or something?)

I have the SAADC ports running, and modified the env_senser to test it, all looks good.

I only want to use the 9160 part.

The client is happy to use webhooks or MQTT to accept the data into their database, nice and simple.

So could you suggest how you may go about this type of implementation?

Option 1, Use nRFCloud for provisioning, FOTA and sample data transactions

Option 2, Use nRFCloud for provisioning and FOTA, but for the sample data, use an HTTP POST method to an external fixed IP server (directly to the database).

Option 3, A better option which I have missed.

Thanks again for your help

Billy

[Markus Tacker (he/him)]

billywalton said:

I have tried V2 but have problems with the AWS, the AWS part is a massive headache for this project

If you have time I would greatly appreciate if you could give some insights on what specifically you don't like, or what could be improved to help you in your current situation.