Setting the transmit power

[lodesmets]

This function isn't documented: bool power(_rf_mode mode, uint8_t index) and the arguments aren't named very good. The mode argument I can understand, but what is index? Is it the transmit power? Between what values can it change?

[facchinm]

Hi @lodesmets , that function signature is a leftover of the Murata firmware compatibility layer (which I belive we can abandon sooner or later). It maps in the firmware to https://github.com/arduino/mkrwan1300-fw/blob/63787fe5ed8bd07119caba20d2065a26004b2261/Projects/Multi/Applications/LoRa/AT_Slave/src/at.c#L382-L397 So mode is ignored while index is the transmit power (from 0 to 5) https://github.com/arduino/mkrwan1300-fw/blob/188a5cd9b595d342b6c00d3dc9e9b9f7a102ef6b/Projects/Multi/Applications/LoRa/AT_Slave/src/command.c#L217 Any proposal on how to improve the function name or add some documentation is well accepted :wink:

[lodesmets]

Any proposal on how to improve the function name or add some documentation is well accepted 😉

Maybe call it transmitPower instead of index that would be a more explaining variable name

[facchinm]

Would you mind submitting a pull request? Thanks!

[lodesmets]

Would you mind submitting a pull request? Thanks!

Done, I just made the argument have a more sensible name. But I don't know what the stronger transmit power is (I guess 5)

[lodesmets]

Pressed the wrong button, I know it is a lot of work, but why not document all the functions?

[facchinm]

why not document all the functions?

Because it's a lot of work :smile: Jokes apart, this library was born to handle the Murata firmware; when we decided to switch to the open firmware module we thought it was a good idea to keep the library compatible.

It was not a great idea in the end, so the long term target is to rewrite the firmware entirely and expose the functionalities in a saner way (and, last but not least, document them properly)

[facchinm]

Ah, I merged the PR, so I'm closing the issue

[ElectronicallyE]

Been playing around with the command modem.power(PABOOST, X);

Based upon this Arduino Forum post, 0 is the highest TX power.

I've done some testing on 0 and 5 and there doesn't seem to be a noticeable difference in SNR or RSSI, no matter if the gateway is close or far from the sensor. One transmission, 0 has a better RSSI and SDR, on another it's 5. So either the command isn't working or the difference is negligible.

I'm setting up MKR WAN 1310 and the transmission as follows:

void setup() {
  Serial.begin(115200); 
  if (!modem.begin(AU915)) {
    Serial.println("Failed to start the MKR WAN 1310.");
    while (1) {}
  };
  delay(5000);
  Serial.println("Firmware version: " + modem.version());
  Serial.println("DevEUI: " + modem.deviceEUI());
  modem.sendMask("ff000000f000ffff00020000");
  modem.setADR(false);
  modem.dataRate(0);
  modem.power(PABOOST, X); //CHANGING BETWEEN 0 AND 5
  join();
}

void join() { // Define the join function
  if (!modem.joinOTAA(appEUI, appKey)) {
    Serial.println("Can't connect to The Things Network. Retrying.");
    join();
  }
  else {
    Serial.println("Connected to The Things Network.");
  }
}

void loop() {
  delay(30000);
  Serial.println("The MKR WAN 1310 has woken up.");
  modem.setPort(1);
  modem.beginPacket();
  modem.print("AA");
  modem.endPacket(true);
}

Any ideas why I'm not seeing a difference with the different transmission powers?