microbit-2of5-font

README | TH-README

A MakeCode extension for the micro:bit that displays numbers on the 5×5 LED matrix in 2 of 5 style.
Inspired by the 2 of 5 barcode family, especially Interleaved 2 of 5 (ITF).

Demo:

• 2of5 stopwatch
• 2of5 password (demo of write2of5)

Project page: https://quarequin.github.io/microbit-2of5-font/

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Features

• Render numbers in classic 2 of 5 patterns on the 5×5 screen
• Support for negative numbers (shown via inverted dots)
• Optional Guard mode (uses the 6th digit as invert reference)
• Optional Transpose mode (swap vertical ↔ horizontal)
• Optional Brightness control (0–255)
• Single-digit display or dual-number display with alignment
• write2of5 helper — maps two bit positions back to a digit (uses binary search)
• Very compact implementation using a single Buffer for all 2 of 5 patterns

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Install as Extension

1. Open https://makecode.microbit.org/
2. Create a New Project
3. Click the gear icon → Extensions
4. Paste this URL and import:

https://github.com/Quarequin/microbit-2of5-font

(The previous URL https://github.com/phatisena/microbit-2of5-font still works.)

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Main Blocks / Functions

Function	Description
write2of5(a, b)	Map two bit positions (0–4) to a 2of5 digit (returns -1 if invalid)
show2of5Number(n, guard, transpose?, brightness?)	Show a full number (up to 5 or 6 digits)
show2of5SingleNumber(n, col, inv, transpose?, brightness?)	Show a single digit at a specific column
show2of5DualNumber(a, b, align, transpose?, brightness?)	Show two numbers side-by-side (Left / Center / Right)

Important Parameters

• guard — when true, the 6th digit controls invert of each digit
• transpose — rotate the display (vertical ↔ horizontal)
• brightness — LED brightness level (0–255, default 255)
• inv — invert the dots of that digit (also used for negative numbers)
• align — Left / Center / Right for dual mode
• a, b (in write2of5) — bit positions (0–4). Must be different.

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2 of 5 Pattern Encoding

Each digit is encoded with 5 bits (exactly two bits set to 1):

0 → 11000
1 → 10100
2 → 10010
3 → 10001
4 → 01100
5 → 01010
6 → 01001
7 → 00110
8 → 00101
9 → 00011

Stored as a compact descending Buffer (the “2of5 magic buffer”):

const pin2of5: Buffer = hex`181412110C0A09060503`

write2of5 uses binary search on this buffer to convert two bit positions back into a digit.

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Edit this Project

1. Open https://makecode.microbit.org/
2. Click Import → Import URL
3. Paste:

https://github.com/Quarequin/microbit-2of5-font

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Technical Info

• Target: micro:bit (MakeCode / PXT)
• Language: TypeScript
• Current version: 6.1.0 (see pxt.json)

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Metadata (used for search, rendering)

• for PXT/microbit