RFM95-LoRa-Wireless-Comm

Sender and Receiver code for the RFM95 LoRa wireless communication.

LoRa Documentation

RadioHead

Heads Up

If wanting to use more than 3 radios you have to modify

lib\RadioHead-1.130\RadioHead{radio class}.cpp

and

lib\RadioHead-1.130\RadioHead{radio class}.h

Also, you might have to find where it is saved locally on your system and modify it there, I haven't been able to test if that is required

In {radio class}.cpp file you add another index to _deviceForInterrupt, where N is the number after the previous, and add

else if(_myInterruptIndex == N)
  attachInterrupt(interruptNumber, isrN, RISING);

void RH_INTERRUPT_ATTR RH_RF95::isrN()
{
    if (_deviceForInterrupt[N])
	_deviceForInterrupt[N]->handleInterrupt();
}

In {radio class}.h declare and add 1 to RH_RF95_NUM_INTERRUPTS

#define RH_RF95_NUM_INTERRUPTS = N
static void         isrN();

Supposedly they had it set up like this because most Arduinos can only handle 2 and MEGAs can only handle 3, but we move different

Pinout for Arduino Leonardo

!!!Leonardo is not currently on a board!!!

CS pins MUST go into INT pins (i.e 0-4, 7), PCINT didn't work in testing but we're also somewhat dumb and might work now

Leonardo ----> LoRa 0 ----> LoRa 1 ----> LoRa 2 ----> LoRa 3

5v ----> VIN

ICSP 3 (SCK) ----> SCK

ICSP 4 (MOSI) ----> MOSI

ICSP 1 (MISO) ----> MISO

GND ----> GND

0 ----> (LoRa 0) G0

1 ----> (LoRa 1) G0

2 ----> (LoRa 2) G0

3 ----> (LoRa 3) G0

4 ----> (LoRa 0) CS

5 ----> (LoRa 1) CS

6 ----> (LoRa 2) CS

7 ----> (LoRa 3) CS

Receiver Spec Sheet

Pinout for Teensy 4.1 on the breadboard

-- CS pins can be on any logic pin, currently using pins defined as CS pins by Teensy -- Chained pins can theoretically go infinitely, just limited by logic pins but check warning above to implement in code

Teensy ----> LoRa 0 ----> LoRa 1 ----> LoRa 2 ----> LoRa 3

5v ----> power rail ----> (LoRa 0) VIN ----> (LoRa 1) VIN ----> (LoRa 2) VIN ----> (LoRa 3) VIN

13 ----> (LoRa 0) SCK ----> (LoRa 1) SCK ----> (LoRa 2) SCK ----> (LoRa 3) SCK

GND ----> (LoRa 0) GND ----> (LoRa 1) GND ----> (LoRa 2) GND ----> (LoRa 3) GND

38 ----> (LoRa 0) CS

37 ----> (LoRa 1) CS

36 ----> (LoRa 2) CS

10 ----> (LoRa 3) CS

21 ----> (LoRa 0) G0

20 ----> (LoRa 1) G0

19 ----> (LoRa 2) G0

18 ----> (LoRa 3) GO

11 ----> (LoRa 0) MOSI ----> (LoRa 1) MOSI ----> (LoRa 2) MOSI ----> (LoRa 3) MOSI

12 ----> (LoRa 0) MISO ----> (LoRa 1) MISO ----> (LoRa 2) MISO ----> (LoRa 3) MISO

CAN ----> 5v !!!Only connect when powering through USB, not the car!!!

CAN ----> GND

CAN HIGH ----> 23

CAN LOW ----> 22

Sender Spec Sheet