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Ask Uno
Embedded Systems + Electronics
A two-Arduino communication system developed to explore serial communication, LCD interfaces, and distributed arithmetic processing.
Type
Serial Communication
Controllers
Arduino Nano + Uno
Communication
SoftwareSerial
Interface
16 × 2 LCD
Development
Electronics
Arduino
Project Context
Ask Uno was developed to introduce serial communication between two Arduinos. The project was divided into three stages, progressing from a single LCD interface to communication between two controllers and finally arithmetic processing across the system.
Reference
01
Two Arduino boards communicate with each other while driving independent liquid crystal displays, allowing information to move between separate controllers.
The system consists of an Arduino Nano, Arduino Uno, two liquid crystal displays, an LCD appliance, resistor, potentiometers, breadboard, and supporting wiring.
Development was divided into three stages: establishing the LCD interface, creating communication between the two Arduinos, and using that connection to transmit and solve arithmetic expressions.
02
Each Arduino drives its own liquid crystal display to create a separate visual interface for each side of the system.
Each liquid crystal display is driven by an Arduino with the display connected to pins 4 through 7. A potentiometer connects to the V0 pin to control LCD contrast.
The Arduino also connects to the Enable and Register Select pins. The Register Select pin switches the display between instruction and character modes.
When Register Select is high, character mode is active and binary input from the data pins prints a character rather than running a display command.
Arduino Nano + LCD
Initial LCD interface
03
SoftwareSerial creates a communication channel between the Arduino Nano and Arduino Uno using pins 8 and 9.
The SoftwareSerial library creates a second serial connection called chat. This connection uses RX and TX on both Arduinos.
Data can then be transmitted between the two controllers using the chat print function.
04
The first stage established the Arduino Nano and LCD interface.
The Arduino Nano was wired to the liquid crystal display on the breadboard. The goal was to take text entered through the serial monitor and print it to the display.
05
The second stage added the Arduino Uno and established communication between the two controllers.
The LCD appliance was first assembled and soldered. It includes built-in brightness control and a pinout that plugs directly into the Arduino.
The Arduino Uno was then added to the previous Nano setup. The first software task was to make the Uno assistant echo transmitted text.
The second task confirmed that the board could receive text from the serial monitor and communicate it to the Uno assistant.
LCD Appliance
Completed LCD appliance
Dual Arduino Assembly
Arduino Nano and Uno communication setup
06
The final stage used the completed serial connection to pass arithmetic expressions between the two controllers.
01
Input
An arithmetic expression is entered through the serial monitor and read by the Arduino Nano.
02
Transmit
The Nano echoes the expression onto its LCD and sends it to the Arduino Uno.
03
Solve
The Uno solves the expression and displays the answer on its own LCD.
07
Separate programs control the Nano and Uno while SoftwareSerial handles communication between them.
Both programs use the SoftwareSerial and LiquidCrystal libraries. The communication channel is configured on pins 8 and 9 and operates at 9600.
The Nano reads an input string from the serial monitor, prints it to its LCD, and transmits the string through the chat connection.
The Uno reads the received expression, separates the characters into operands and an operator, and uses the program's solution function to perform the arithmetic.
08
Parts Table
Qty.
Arduino Nano
1
Arduino Uno
1
Liquid Crystal Displays
2
LCD Appliance PCB
1
330Ω Resistor
1
10K Pot
2
Full+ Breadboard
1
Wires
Assorted
09
The completed system receives an arithmetic expression, displays and transmits it from the Nano, processes it on the Uno, and displays the resulting answer.
Final Ask Uno Assembly
Arduino Nano + Arduino Uno + dual LCD interface
Ask Uno