A project with two microcontrollers returns a web-enabled pager
2024-03-20 14:14
"The goal of this project is to allow the user to send short text messages, which will then be received on the Wi-Fi [Espressif microcontroller] ESP8266 and displayed on an Arduino with an LCD screen," explains João Santos.
The landing page offers the user two fields: one for the sender's name and one for a message up to 160 characters long. "I added a protection to the backend that allows a message to be sent only if none has been sent within a certain time," says Santos.
The receiving device consists of two microcontroller-based boards, one with a Microchip ATmega328P and the other with an Espressif ESP8266. "I decided to connect the screen to an Arduino Uno board.
The ESP8266 provides network connectivity via Wi-Fi, sending received messages to the I2C-compatible Arduino UNO for formatting and output to the LCD1602 character display. Two buttons let you scroll through the messages, using a resistor ladder to combine both into a single analog input, and a buzzer sounds when a new message arrives.
"What I learned: don't buy cheap development boards," Santos notes in the full project description available on Medium.