MCU Delay Generator

MCU delay routine generator with:

• a Web UI built with Vite + Preact
• a bundled CLI published as mcu-delaygen

Features

• Generates blocking C delay routines for three MCU families:
  • ATmega328P (AVR 8-bit, Arduino Uno) -- default clock 16 MHz
  • STC89C52 (classic 12T 8051) -- default clock 11.0592 MHz
  • STM32F103C8 (ARM Cortex-M3, Blue Pill) -- default clock 72 MHz
• Two generation modes per MCU:
  • Timer mode -- uses a hardware timer (Timer1 CTC on AVR, Timer0 mode-1 on 8051, SysTick on STM32); handles delays longer than one timer period by chaining multiple timer intervals
  • Software loop mode -- generates a busy-wait loop with a configurable cycles-per-iteration calibration value so the output can be tuned against hardware measurements
• Accepts arbitrary delay strings (500us, 10ms, 2s) and custom clock frequencies
• Supports a custom function name in the generated output
• All arithmetic uses integer bigint throughout -- no floating-point rounding errors
• Available as a browser-based Web UI (no installation) and a Node.js CLI (mcu-delaygen)

Requirements

• Node.js 20.19+ or 22.12+
• Bun for development and tests
• chafa
• zip for generating the Web release archive

chafa is only required when regenerating the CLI icon banner from the SVG favicon. The Node.js floor matches the current Vite 8 / Rolldown toolchain used by this repository.

Install

Install the published CLI from bun:

bun install -g mcu-delaygen

or use npm:

npm install -g mcu-delaygen

Or download release assets from Codeberg Releases:

https://codeberg.org/xchacha20-poly1305/mcudelay-gen/releases

Development Setup

bun install

Development

Run the Web app in dev mode:

bun run dev

Run the CLI entrypoint from source:

bun run cli -- version
bun run cli -- list
bun run cli -- generate --mcu stc89c52 --delay 10ms

Build Guide

Web Build

Build the Web app:

bun run build

Output:

• dist/

Preview the built Web app locally:

bun run preview

CLI Build

Build the bundled CLI:

bun run build:cli

Output:

• dist-cli/cli.js

Run the built CLI directly:

node ./dist-cli/cli.js version

Build all release assets in one pass:

bun run build:release

Output:

• versioned single-file JS CLI
• mcu-delaygen-web-v<version>.zip
• mcu-delaygen-v<version>-checksums.txt

Release Flow

Push a semver tag that matches package.json:

git tag v0.1.0
git push origin v0.1.0

The Forgejo workflow will:

• verify the tag matches package.json
• run the test suite
• build release assets
• publish a Codeberg release
• publish the npm package

Icon Generation

The project icon source is:

• public/favicon.svg

It is used in two places:

• the Web app favicon and page branding
• the CLI version banner

The CLI banner is generated into:

• src/adapters/cli/generated-banner.ts

When public/favicon.svg changes, regenerate the CLI banner before rebuilding the CLI:

bun run build:banner
bun run build:cli

Equivalent direct command:

node ./scripts/build-cli-banner.mjs

The banner generator uses chafa with symbol output and truecolor mode to preserve the original icon colors in terminal output.

Test

Run the full test suite:

bun test

Lint and Format

Lint the source:

bun run lint

Auto-format the source:

bun run format

Both use Biome. Configuration is in biome.json.