Sending asynchrously uplink data

End Devices (Nodes) LMIC
1

I an building a cartracking node using the Arduino LMIC Library.

In the examples the transmission of uplink data is periodically scheduled with the const unsigned TX_INTERVAL value and considering the airtime limits.

If the car is stopped and the gps position is not changed (that much) or the speed is below 5kmh, I don’t want to send data at al.

I noticed suspending the LMIC_setTxData2 in the TTN-APB Example stops the sending of data at all.

What is the right way to suspend the transmission of data?

2

That depends on your sketch. Generally speaking it would be to stop queuing packets for transmission by not calling do_send.

3

Thx for the swift respons.

I am using the ABP Example as base code. I see that do_send is only called once, at the end of setup().

This triggers apperently the periodic sending of data.

Can you gave me an example how to suspend this?

4

do_send ends with a comment that the next transmission is scheduled after TX_COMPLETE event. So may-be take a look there? If you do you might notice a line

os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);

which causes do_send to be called again after some ( TX_INTERVAL ) time.
Remove it, add do_send with an appropriate interval to loop and you are done.

1 Like
5

Thanxs for your help. It is apperantly a timer construction. Don’t have any expercience with that, but I going to follow-up your advice.

6

Change the code as you advised.

Works as a charm. Thnx of your support.