{"id":27641326,"url":"https://github.com/diegograham/calculator","last_synced_at":"2026-04-29T01:32:24.610Z","repository":{"id":289525757,"uuid":"971559408","full_name":"diegograham/Calculator","owner":"diegograham","description":"An Arduino-based calculator using a keypad and LCD display to perform basic arithmetic operations with buzzer feedback.","archived":false,"fork":false,"pushed_at":"2025-04-23T18:09:25.000Z","size":0,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-04-23T18:44:41.271Z","etag":null,"topics":["arduino","calculator","electronics","embedded-systems","keypad","lcd"],"latest_commit_sha":null,"homepage":"","language":"C++","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/diegograham.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2025-04-23T17:52:01.000Z","updated_at":"2025-04-23T18:11:33.000Z","dependencies_parsed_at":"2025-04-23T18:44:44.132Z","dependency_job_id":null,"html_url":"https://github.com/diegograham/Calculator","commit_stats":null,"previous_names":["diegograham/calculator"],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/diegograham%2FCalculator","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/diegograham%2FCalculator/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/diegograham%2FCalculator/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/diegograham%2FCalculator/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/diegograham","download_url":"https://codeload.github.com/diegograham/Calculator/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":250535057,"owners_count":21446503,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["arduino","calculator","electronics","embedded-systems","keypad","lcd"],"created_at":"2025-04-23T23:43:49.066Z","updated_at":"2026-04-29T01:32:24.579Z","avatar_url":"https://github.com/diegograham.png","language":"C++","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Calculator 2\n### By: Diego J. Graham\n\n## Description\n\n**Calculator 2** is an Arduino-based project that uses a membrane keypad for user input and an LCD to display the calculation. The calculator can **add, subtract, multiply, and divide** two integers, and it displays the result as a **float**. It also includes a **buzzer** for audible feedback on button presses.\n\n---\n\n## Features\n\n- Accepts input via a 4x4 membrane keypad.\n- Displays real-time input and output on a 16x2 LCD.\n- Supports basic operations: `+`, `-`, `*`, and `/`.\n- Automatically evaluates the expression when `=` is pressed.\n- `C` button clears all inputs.\n- Built-in buzzer beeps with every keypress.\n- Handles division-by-zero errors gracefully by displaying \"ERROR\".\n\n---\n\n## How It Works\n\n- The user enters the **first number**.\n- The user then presses an **operator** (`+`, `-`, `*`, `/`).\n- The user enters the **second number**.\n- Pressing `=` evaluates the expression.\n- Pressing `C` clears the input and resets the calculator.\n\n---\n\n## Required Libraries\n- Keypad - handles keypad input\n- liquidCrystal - controls the LCD display\n\n--\n\n## Components Used\n\n- Arduino (MEGA or compatible board)\n- 4x4 Membrane Keypad\n- 16x2 LCD Display\n- Piezo Buzzer\n- Jumper Wires\n- Breadboard\n\n---\n\n## Schematic\n\nA complete schematic is included in the repository under the filename:\n\n\n---\n\n## Getting Started\n\n1. Clone the repository.\n2. Open `Calculator2.ino` in the Arduino IDE.\n3. Connect the components as shown in the schematic.\n4. Upload the sketch to your Arduino board.\n5. Use the keypad to input and calculate!\n\n---\n\n## Notes\n\n- The result is always displayed as a float (e.g., `4.00`).\n- Make sure your keypad wiring matches the `rowPins` and `colPins` defined in the code.\n- LCD must be initialized using pins `7, 8, 9, 10, 11, 12`.\n\n---\n\n## Future Improvements\n\n- Add decimal support for more precise inputs.\n- Improve input validation (e.g., multiple operators).\n- Add support for chained calculations.\n\n---\n\n## License\n\nThis project is open source and free to use with credit.\n\n---\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdiegograham%2Fcalculator","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdiegograham%2Fcalculator","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdiegograham%2Fcalculator/lists"}