I am a bit confused on the operating temperature of RAK3172 (it may sound stupid).
The datasheet of RAK3172 shows that the operating temperature range is between -40° C ~ 85° C. However, in this post, one of the staff showed that the datasheet of the XTAL, which suggests an operating temperature between -20 °C ~ 85° C.
Does it mean that the RF component of RAK3172 can fail for any temperature below -20 °C?
I am asking this since I am building projects that may apply to the Arctic, where the temperature can often fall below -20 °C.
The docs should be updated. Regarding your requirements, we will release soon a RAK3172T variant which supports TCXO. I will check its minimum temperature range.
The datasheet link provided appears to be a crystal not a TCXO.
As the RAK3172T appears to now be available to order, can you provide information about code changes required for those of us doing low-level firmware development?
Andrew,
I’ve followed a wiki which reckoned to be based on your use of the rak3172-T. I have it to the point that it sends a join request, but the join accept although seen by my gateway is not seen by the rak3172-T at all. I tried to put a breakpoint on the IRQ handler for RX_DONE, but it never fires. Do you have any helpful hints? or better still a complete source for a basic end-node.
In my experience, Join Accept not received by the transceiver but Join Request pushed thru could to the network can be (maybe) frequency band misconfigured. I experience this before. Also, is the distance between the gateway and the device reasonable (not too far and not too close). Are the LoRaWAN version compatible as well? in STM32WL SDK, it has 1.0.3 and 1.0.4 and is configurable on the sourc code (AFAIR on header file).
I saw this when I flash a RAK3172-T with a RAK3172 (without TCXO) firmware.
Are you sure you flashed the correct firmware RAK3172-T_latest_final.hex
The one named RAK3172_latest_firmware.hex is for the variant without TCXO.
I have seen a problem like that when I have the I/O pins for the RF switch wrong.
My test gateway is only a couple of metres away, so having the RF switch in the wrong state doesn’t cut off the Tx power for the JOIN_REQ but just heavily attenuates it. Enough signal gets through to the gateway for it to receive the packet.
But when the gateway transmits the ACCEPT, the bad RF switch setup isn’t allowing enough signal back for the module to see the packet.
So, my guess is either the RF switch code hasn’t been altered from the original STM32CubeIDE generated code, or else the wrong version of the RAK3172 RF switch code is in play.
Note that this is the key firmware difference between the RAK3172 and the RAK3172-SIP.
The only other possibility that occurs to me is a region settings mismatch between the device and the network.