“Via RYLR998 LoRa module and Arduino Nano, create a two-way radio (transceiver) w/ a 4x4 keypad to transmit and receive text messages.
For a long time, I have wanted to experiment with LoRa (short for long-range), which is a spread spectrum modulation technique derived from chirp spread spectrum (CSS) technology. Since I am fond of vintage walkie-talkies utilizing radio waves, I decided to create a walkie-talkie (two-way radio) with a LoRa module from scratch to transmit and receive short text messages.
After perusing different LoRa module datasheets, I decided to employ the RYLR998 LoRa (transceiver) module since I wanted to make this project as compact as possible. The RYLR998 LoRa module provides ultra-long range spread spectrum communication with high sensitivity and high interference immunity while minimizing current consumption. Also, this module has a built-in antenna and supports AT commands via serial communication. You can inspect the product datasheet from here.
After connecting the RYLR998 module to the Arduino Nano, I utilized a Nokia 5110 screen and designed a custom 4x4 keypad with pushbuttons to obviate the need for sending and displaying text messages via the serial monitor. Finally, I added a 5mm common anode RGB LED to indicate different menu options and message notifications.
After completing wiring on a breadboard and testing the code for two LoRa-based walkie-talkies (two-way radios), I designed an Iron Man-inspired PCB for this project. I thought Iron Man was germane to my vintage walkie-talkie theme due to a scene from Iron Man 3 near the end of the movie, in which all remaining armors communicate with each other via radio waves covertly. Even though radio is seldom utilized by Iron Man in comics pages, I was inspired by the movie to design Iron Man-themed walkie-talkies (two-way radios) after recently rewatching it :)”