The linking machine is named generically, as it aims to help people memorize, thus linking the knowledge together.

For English learning, it aims at advanced learners, who already have a basic vocabulary, since the user interface is purely English, without any Chinese or other languages for translation or hints.

Physically, the linking machine is a small device with a eye friendly display, like reflective monochrome LCD, or E-ink, with capacitive touch screen, and a few knobs and buttons for navigation.

physical design

Main components in PCB:

• mcu: esp32s3-wroom, and optional place for esp32-c3-wroom
• display: 4.2 inch monochrome LCD with touch screen
• storage: soldered flash and sdcard slot
• input: a knob, 2 buttons
• audio: output for earphone and speakers, and mic
• power: usb-c for charging and power supply, and battery
• extension: unused io pins are exposed via headers like 1.0mm/1.27mm pitch, and a few test points for debugging and flashing

English learning

For vocabulary building, the linking machine is mainly built on the idea of wordnet, which is a graph of words, where each word is a node, and the edges connect the words with their synonyms, antonyms, and other relations.

Vocabulary building features:

• phonics: showing the phonics of the word
• synonyms and antonyms
• example sentences, and words in the sentences are also clickable.
• wordnet: showing the wordnet of the word as the main view. it has 155,327 words.

Mathematics

The mathematics part is still under development. Initial ideas are discussed below.

For mathematics, the linking machine may also uses the idea of graph, where each node is a mathematical concept, but the crucial part is to organize the concepts in a way that is far apart from the traditional way of teaching mathematics:

• equations
• functions
• operations: addition, subtraction, multiplication, division, exponentiation
• expressions: polynomials, rational expressions, trigonometric expressions, etc.

Other software

The machine/tablet is open source, so users can flash whatever they want, like the Tac or use it like a development board, as it has exposed IO pins and a not too small touch screen, making it suitable for:

• information display
• control panel for other devices
• (quasi) portable computer, like m5stack
• retro style electronics like PDA, electronic dictionary, etc.