LORA demonstration kit

LORA transmission tests codes

This codes have been tested using ESP32WROOM dev board. They use VSPI for SPI and HOPE-RFM95W Lora Modules pictured below. The connections are almost similar if using other LORA modules such as the Adafruit RFM9x modules.

Needed libraries

Lora library by Sandeep Mistry (https://github.com/sandeepmistry/arduino-LoRa)

Hardware setup

Connect the LORA modules to ESP32 as follows:

LORA	ESP32
3V3	3V3
GND	GND
MOSI	23
MISO	19
SCK	18
NSS(CS)	4
RESET	2
DIO0	22

These connections can be similar for the transmitter and the receiver.
Note: NSS(CS) can be choosen to be any pin. The DIO0 pin is the IRQ pin that MUST be capable of hardware interrupt. On ESP32, any GPIO can be an interrupt pin

Frequency

Use 868Mhz for Africa

Antenna

I used a single-core 30AWG wire antenna(am not sure that's the right one but it worked just fine) of 8cm as per the table of frequencies below.
You can use the common whip antenna but rated for 868-928Mhz frequency.

Tests done

1. Simple packet send and receive

This tests very basic sending and receiving. The transmitter sends a packet with a message count. The receiver parses the received packet and prints out on the serial monitor. The screen shot below shows:

Sender

Receiver

2. Simple button and LED control

This tests how to control a remote LED using a button via LORA We attach a button on the sending esp32, when we press the button, the LED on the receive button gets turned ON The results from the serial monitor are shown below:
Sender