Digital content fails in Indian classrooms for reasons that have very little to do with the content. The projector is bright but the room is brighter. The connection works in the office and not in the annexe. The teacher has thirty-five minutes and the first four go on finding the right file.
Teach on Board is EdunodeX’s classroom player, and its design constraints come from those conditions rather than from a demo room.
What a projector-first lesson player has to do
A player used in front of a class has a short list of hard requirements.
It has to open fast, from the class the teacher is about to take, without a search. It has to be readable from the back bench, which means large type and high contrast rather than dense slides. It has to be operable while the teacher is facing the class. And it has to keep working when the network does not, because a lesson that stops halfway is worse than no lesson at all.
Teach on Board is reached from the teacher’s own class and subject, so the path from “my next period is Class 5 Mathematics” to a lesson on screen is a short one. It runs full-screen with a dedicated board theme, and it is structured as a period rather than as a slideshow: attendance, choosing the lesson, teaching it, practice, and closing out.
The slide types a lesson is built from
A board lesson is a sequence of typed slides, and each type is a purpose rather than a layout.
Picture talk opens a topic from an image with spoken prompts. Vocabulary introduces terms with a word, a picture and audio. Concept pairs an image with an explanatory sentence. Label diagram places hotspots on a figure for students to identify. Read passage carries a text extract. Match and pick are the light interactive checks — pairing items, or choosing the right option from pictures.
For the older classes the types get more structural. Worked example shows a full solution step by step with the reasoning for each step. Faded example gives the same structure with some steps blanked, so the student completes progressively more of the working themselves. Problem set is straightforward practice. Number line and graph plot handle the visual mathematics that is genuinely hard to draw well on a whiteboard. Notebook slides push work off the screen and into the exercise book, with a model image of what the page should look like. Quiz closes the loop with options and an explanation of why each answer is right or wrong.
A slide type the player does not recognise renders a visible notice rather than a blank screen, so an unexpected lesson never leaves a teacher staring at nothing in front of a class.
Read-aloud narration synced to the item on screen
Slides carry per-item audio, which the player assembles into an ordered read-aloud sequence: an optional slide-level introduction first, then each item in its natural reading order for that slide type.
As a clip plays, the corresponding item on screen is highlighted. Making that work reliably needs the narration sequence and the slide component to agree on what each item is called, so both derive the same stable key for an item — its own identifier when it has one, and its position otherwise.
Where a slide has no audio, the listen control is simply disabled rather than playing silence.
The point of this is not novelty. It is that a teacher in a Hindi-medium school teaching an English chapter, or a teacher covering a subject outside their specialism, gets correct pronunciation and pacing without having to perform it themselves.
Working when the classroom connection drops
Lesson assets are cached locally in the browser’s own database, keyed by the asset’s storage key.
The authentication path is unchanged by this: bytes are still fetched through the authenticated client, and the cache layer only decides whether to go to the network or to local storage and then keeps the result. Total stored bytes are bounded to roughly 250 MB, with the least recently used assets evicted, so a device used every day for a year does not grow without limit.
Two deliberate choices are worth naming. There is no service worker involved — caching is scoped to the board player rather than to the whole application, which avoids the familiar problem of a stale cached shell surviving an update. And when the browser’s storage is unavailable or refuses to open, in private browsing or an older browser, the cache silently falls through to the network instead of failing.
The practical result is that a lesson a teacher has already opened once on that machine replays even if the connection drops mid-period.
Adapting a shared lesson for your own class
Catalogue lessons are written for a class in general. A specific Class 4 section, six weeks behind after a long absence, is not a class in general.
A teacher can adapt a lesson in two ways. Simplify rewords the same lesson at an easier reading level, optionally with a target level, keeping the structure and the assets and changing only the language. Regenerate takes free-text instructions and rebuilds the lesson against them.
Both produce a private variant belonging to that teacher, attached to a class. The shared lesson is untouched, no academic record is written, and the request is scoped to the teacher’s own board — a lesson identifier belonging to another board returns not-found rather than content. Because nothing destructive can happen, adaptation needs no confirmation step.
Attendance, lesson log and the rest of the period
The player is not only a display surface. It sits inside the period.
Attendance can be marked at the start, from the same screen, before the lesson opens. Progress is recorded as lessons are completed, which is what lets a teacher and a principal see which chapters a section has actually covered rather than which ones were planned. And the period can be logged against the teaching plan, so the term-level plan reflects what was taught rather than what was scheduled.
That connection is the difference between a content player and a teaching system. A slideshow tells you a lesson existed. Teach on Board records that this class, on this date, covered this chapter — and that record is what the teaching diary, the syllabus pacing view and the principal’s monitoring summary all read from.