问题
Do you know how to set up the Spreading Factor to 12 in a Mbed-OS LoRaWAN protocol APIs to connect to a LoRaWAN network using OTAA?
I'm trying to make LoRA node to use Spreading Factor SF12, because the default one is SF7. I know that in the PHY layer we can change Radio configurations. There are several examples to change between the different sub-GHz frequency bands, however, I can't find one on how to change the LoRa modulation SF between 7 and 12 and with a bandwidth of 125 kHz.
I'm using an SX1276 radio at EU 868 MHz
config.
In the source code you can find the SF7-12 different configurations, but there is not a clear way to set it up. These configs are the definitions (#define) DR_0, DR_, etc ).
In the configuration file in the Phy part you find some example like this:
"phy": {
"help": "LoRa PHY region. 0 = EU868 (default), 1 = AS923,
2 = AU915, 3 = CN470, 4 = CN779, 5 = EU433,
6 = IN865, 7 = KR920, 8 = US915, 9 = US915_HYBRID",
"value": "0"
},
But there is no examples or description for the Spreading Factor.
I would like to change it via source code, rather than the configuration file.
EDIT 1:
after Jon's answer, I add the following lines, but still not forcing the SF12 Joins.
retcode = lorawan.disable_adaptive_datarate ();
retcode = lorawan.set_datarate (0); // DR_0
回答1:
Call:
lorawan.set_datarate(0); // SF12 125 KHz
Make sure to:
- Disable ADR.
- Either use ABP, or call the function above in the
JOIN_SUCCESS
event handler. This is because join procedure always starts at SF7, and then keeps the data rate on which the join succeeded.
来源:https://stackoverflow.com/questions/54882984/mbed-os-5-9-lora-set-up-in-sf7