Is it possible to apply the rak3172 send&receive function simultaneously?

LPWAN Modules / EVBs
1

Is it possible to apply the rak3172 send&receive function simultaneously?

rak3172 Currently only checked in one direction.
In the case of the rak4270, it was confirmed that the send & receive function can be applied at the same time by uploading the custom firmware.

In other words, we want bi-directional communication in a 1:N configuration.

Can rak3172 be applied simultaneously?
for example

  1. B device > A gateway periodic transmission
  2. Gateway A > Device B Operation
  3. Device B operation complete > Gateway A
  4. B device > A gateway cycle transmission
2

Welcome to RAK forum @Athurian ,

May I know what you mean with rak3172 Currently only checked in one direction.?

Based on your example with B device and A gateway, it seems to be a standard uplink and downlink scheme. This can be done by RAK3172 or any LoRaWAN compatible end-device.

3

In the case of RAK 4270, there is a function of simultaneous send & receive mode with custom firmware on github.

What I’m curious about is whether the RAK 3172 product works simultaneously in send & receive mode.

4

Technically the LoRa transceiver can be in either RX or in TX mode, but not in both at the same time.

What the example does is that you setup the device as either RX or TX and it stays in that mode.

If you want a mix, you can do the following:

// Start RX with TX enabled

api.lorawan.precv(65533); // Start RX but keep TX possible as an option

Then if you need to send something

api.lorawan.psend(your_length, your_payload);

and the device goes back to RX mode after it has finished sending the packet.

REMARK

I did not test this. This is taken from the RUI3 documentation

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1 Like
5

Oh, I see. Then, is it possible to configure 1:N configuration?

For example, with rak 3172 units, 1 out of 3 will be attached to the gateway device and 2 will be attached to the equipment

6

Maybe you can elaborate your setup.

My first reply is related to LoRaWAN.
Then @beegee reply is related to LoRa P2P.

Whichever mode you use (LoRaWAN or LoRa P2P), the semtech lora transceiver only operates in half-duplex. It can only act as TX or RX one at a time. If it is transmitting, it cannot receive. It is receiving, it cannot transmit. But can it can switch mode TX or RX mode easily.

The 1:N configuration is vague to us. To add more on the confusion is the 1/3 to Gateway then 2/3 to the attached equipment. To be honest, I lost on the current setup you have :slight_smile:

7

Have found that to be also true of the standard IDE LoRaP2P example for RAK11310. Is it not at all possible to extend that example for ping-pong messaging? Have tried essentially rerunning the setup for transmit and receive. But, naturally, that does not work. Are there any possibilities?

The application is flood-messaging based on LoRaP2P. Using a different company’s transceiver (no longer manufactured), was able to build such a network and published the results. The transition to RAKwireless has gone well, thanks to this forum, documentation, and examples. But have now run into the problem of not being able to build a relay, a unit that both transmits and receives, albeit not at the very same time. Documentation and software for this evolving project is posted here: GitHub - SoothingMist/Scalable-Point-to-Point-LoRa-Sensor-Network: Builds a peer-to-peer network of LoRa transceivers for remote sensing. Uses flood-messaging to eliminate need for LoRaWAN and third-party services..

How can the standard IDE LoRa-P2P example for RAK11310 be expanded so that each node can be switched between transmit and receive (LoRaP2P_Rx, LoRaP2P_Tx)?

8

confused and maybe give wrong answer

The thread was about RAK3172 and RUI3. Now you are asking about RAK11310.

For RAK11310:

Set up both RX and TX parameters.
Then enable RX while listening and if you want to transmit, just do the TX and on the TX finished callback switch RX on again.

The PingPong example of the library does exactly that, however, it is written generic for ESP32/nRF52/RP2040 and might need some changes or simplifications for the RAK4631.

For RUI3 it is basically the same, just different api calls.

For RUI3/RAK3172

Check the example code in the BSP LoRa P2P it shows how to setup the device for RX and TX and exchange messages between two devices.

(But I never tried it by myself.)

9

The original RUI3 example has some problems, here is an simplified and improved version:

LoRa_P2P.ino (4.2 KB)

10

My Bad. Apologies for the confusion caused by my attempt to broaden the conversation. Started a new thread and referenced this one. Lessons Learned…