nRF9160: LTE Sensor Gateway

[Marshed]

I have managed to upload data from nRF52832 using nRF9160. I upload the data as tempreture sensor (although they are just values in mV), and my interface at the nRF connect for Cloud looks like this 

my questions are 

1. How can I change this interface? Instead of Temperature i want to use another label, for example voltage.
2. Are the data permanently stored in my cloud account? 
3. If they are, how can i retrieve them for further processing. 
4. Can I move the data to other website such as Microsoft Azure or Power BI?

please assist 

[Didrik Rokhaug]

Hi.

Have you seen the API documentation for nRF Cloud? You can find it if you log in to the cloud, and select "Device API" in the menu on the left side.

According to the API documentation, the messages are persisted indefinitely and can be retrieved using REST and GraphQL.

As it is possible to fetch the stored messages, it should be possible to access the data from other places. It is also possible to send the data directly to your own cloud service.

This link describes how to connect the nRF9160 to Google Cloud, and the nrf_cloud library can be used as a starting point for connecting to your own AWS instance.

Best regards,

Didrik

[Marshed]

I have tried to use the link to connect the nRF9160 to Google Cloud, but whenever I compile the code i get this error 

undefined reference to `zepfull_private_der' in the gcloud.c 

any solutions?

[Didrik Rokhaug]

Did you create your certificates?

In src\private_info there is a python script to create these keys. To do this we used the command below while in the private_info folder. DEVICE_NAME was replaced with the name of our device.

python create_keys.py -d DEVICE_NAME -e

[Marshed]

I did that but it gave me this error

so instead I ran these commands on openssl

ecparam -noout -name prime256v1 -genkey -out bolt-001-private.pem

req -new -x509 -key bolt-001-private.pem -out bolt-001-cert.pem -days 1000000 -subj /CN=bolt-001

to create my certificates

was this not a good workaround?

[Didrik Rokhaug]

Close, but not quite.

If you look at the script it then parses the private key into the der format and outputs the result in an array in a new C file.

The error from the Python script indicates that it was not able to run openssl. Is openssl in your PATH environment variable? If not, try to add it.

If you are able to run the Python script where you generated the certificates, that should also work (if this is in another folder you would have to copy the output files into the private_info folder).

[Marshed]

how can I add openssl in my path environment variable?

[Didrik Rokhaug]

https://www.computerhope.com/issues/ch000549.htm

[Marshed]

Thanks this works fine, 

back to REST API, I have been trying to retrieve some messages sent to the cloud using 

 http api.nrfcloud.com/.../messages exclusiveEnd=2019-08-01T00%3A00%3A00.000Z Authorization:"Bearer cf3741f41d4717c94700e541aa642e0a263919f9"

but I have been getting IncompleteSignatureException error 

can you assist

[Didrik Rokhaug]

The messages call requires 2 parameters, inclusiveStart and exclusiveEnd. Both of these are a part of the url, so the url would be similar to this:

https://api.nrfcloud.com/v1/messages?inclusiveStart=2019-01-01T00%3A00%3A00.000Z&exclusiveEnd=2019-08-01T00%3A00%3A00.000Z

However, Windows CMD parses the & (right before exclusiveEnd), so it must be escaped for the url to be read correctly,  so your command would be similar to this:

http https://api.nrfcloud.com/v1/messages?inclusiveStart=2019-01-01T00%3A00%3A00.000Z^&exclusiveEnd=2019-08-01T00%3A00%3A00.000Z Authorization:"Bearer <your API token"

Note the ^ before the &

[Marshed]

Hey

the reply is still the same 

IncompleteSignatureException error

can you assist?