function to create a packet

Projects Programming
1

Hi,

I'm would like to write an arduino function that creates a packet to be transmitter over a radio.

I don't have much experience with arduino. Could somebody point me in the general direction how to do this?

In the header I want to put

  • the baord ID (2 bytes)

and the payload

  • temperature value (2 bytes)
  • humidity value (2 bytes)

Appreciate any guidance.

Kind regards
Conor

2

How will the data be sent to the transmitter? Depending on how you need to send it, you might organize it as a structure. Then you could fill in the structure members of the packet, treating each one as a string. The sample below shows one way to package the data and display it on the Serial monitor:

struct messagePacket {
   char boardID[3];        // You need the extra byte for the null string termination character, '\0'
   char temperature[3];
   char humidity[3];
};

struct messagePacket myPacket;


void setup() {
  
  struct messagePacket myPacket;

  Serial.begin(9600);
  strcpy(myPacket.boardID, "01");
  strcpy(myPacket.temperature, "75");
  strcpy(myPacket.humidity, "90");

  Serial.print("ID = ");
  Serial.println(myPacket.boardID);
  Serial.print("temperature = ");
  Serial.println(myPacket.temperature);
  Serial.print("humidity = ");
  Serial.println(myPacket.humidity);
  
}

void loop() {

}

The advantage of a structure is that it can keep dissimilar data types within a single data item.

3

Hi,

I'm using the this arduino module for the radio

https://www.cooking-hacks.com/documentation/tutorials/extreme-range-lora-sx1272-module-shield-arduino-raspberry-pi-intel-galileo#step3_2

If you go the section - "Transmission without ACK" and expand the code.

Instead of message 1 and 2 in the example, I would like to pass the message.

Will this work?

Thanks

4

Do you have the hardware they suggested you buy? If so, have you tried their sample code? If so, what happened? Since I've never used this system, I have no idea what should/will happen.

5

Hi EcoJack,

If you had time, would you mind showing me how you unpack a structure when it is received and assign each bit to a variable?

Could I say for example:

ID = myPacket.boardID

Thanks