Getting Started¶

1. Build Tasmota with TinyC¶

Add the following to your user_config_override.h:

#define USE_TINYC         // Enable TinyC VM (XDRV_124)
#define USE_TINYC_IDE     // Self-hosted browser IDE (requires USE_UFILESYS)

USE_TINYC_IDE adds the /tinyc_ide.html endpoint. It requires a filesystem-enabled build (USE_UFILESYS).

Or grab a pre-built binary from the Releases page and flash it directly.

2. Upload the IDE¶

Download tinyc_ide.html.gz from the testing release.
In Tasmota, open Consoles → Manage File System (or POST to http://<device>/ufsu).
Upload tinyc_ide.html.gz to the root of the filesystem.
Open http://<device-ip>/tinyc_ide.html in your browser.

The TinyC driver adds its own console page to the Tasmota web UI — one row per VM slot, program upload, bytecode repository, and a shortcut to open the IDE:

Elements on the device console¶

TinyC VM Slots — up to six independent VM instances (0–5). Each row shows the currently loaded .tcb file and its size, followed by four action buttons:

Button	Action
green	Start / resume the program in this slot
dark	Stop execution and free heap memory
blue	Reload the same `.tcb` from flash and restart
A blue	Toggle autoexec — this slot runs on every boot

Load Program — pick an existing .tcb already on the device filesystem and load it into the chosen slot. Delete All .tcb wipes every compiled bytecode from flash (not the source .tc files on your PC).

Repository — online bytecode library. The dropdown lists pre-compiled examples; Download & Load pulls the file to the device and loads it into the selected slot in one step.

Upload Program — push a locally compiled .tcb straight to a slot. Useful during development when you're iterating on a program outside the IDE.

TinyC IDE — opens /tinyc_ide.html in a new tab (served straight from the device filesystem; no cloud, no external host).

Display Mirror — opens a live browser view of the attached display for devices with a connected TFT/OLED/e-paper panel.

Werkzeuge / Tools — returns to the standard Tasmota Tools menu.

3. Your first program¶

void main() {
    addLog("Hello from TinyC!");
}

void EverySecond() {
    float t = temperature();
    char buf[64];
    sprintf(buf, "temp=%.1f C", t);
    addLog(buf);
}

Ctrl+Enter compiles.
Ctrl+Shift+Enter uploads + runs.
Stop button halts execution.

Console output appears in the Tasmota Console tab.

Elements in the browser IDE¶

Top toolbar (left to right):

Button	Purpose
New	Empty editor + fresh filename
Open	Load a `.tc` source file from your PC
Save	Save the current source to your PC
Load Example…	Pick from ~65 bundled programs (sensors, displays, networking)
-DBOARD_…	Board / feature-flag preset — sets `#define`s the compiler sees
Compile	Parse + generate bytecode (output on the left pane)
Run	Execute the compiled bytecode in the in-browser VM (no device needed)
Upload	Send the `.tcb` to the connected device's filesystem
Run on Device	Upload + load into slot + start, all in one click
Device Files…	List / download / delete files on the device filesystem
Save File	Save both source and compiled bytecode to the device
Close	Close the current tab
EN / DE	UI language toggle

Left pane tabs — compiler introspection:

Output — compiler messages, VM stdout, error locations
Disassembly — human-readable bytecode listing with opcode offsets
AST — parsed syntax tree (useful when a construct isn't compiling as expected)
Hex — raw .tcb byte dump for inspection or manual upload
VM State — live registers, stack, heap, and globals while a program runs

Right pane tabs — sources:

editor.tc — the TinyC source you're editing
SML Descriptor — separate text buffer for smart-meter descriptor lines; sent to the device alongside the program when present

Status bar (bottom) — 19 files on device shows the count of files on the device's filesystem; updates as you upload or delete.

4. Where to go next¶

Browse the function reference — every syscall with signatures and examples.
Look at the examples — working code for common sensors, displays, and protocols.
See the gallery — screenshots of projects on real hardware.