"Lightweight" JS interpreter for ESP32. Provides JS-based eventloop implementation and native asynchronous network and timer functions. Because of the limited memory on ESP32-WROOM modules, the full functionality is currently only realizable on ESP32-WROVER modules, that include additional 4MB of SPIRAM memory.

Getting started

API

Compatibility

Install esp-idf 4.2 on your system.

Clone esp32-javascript inside your esp directory (normally ~/esp):

    cd ~/esp
    git clone https://github.com/pepe79/esp32-javascript.git

Change into ~/esp/esp32-javascript.

    cd ~/esp/esp32-javascript

Maybe you want to change the BOARD_VARIANT in the ./CMakeLists.txt file.

First build the project with

    idf.py build

Connect your ESP32 Dev Board via USB and run

    idf.py flash monitor

Use the keyboard shortcut AltGr + ] to leave serial monitor.

Now you have installed the pre-configured boot script.

If this is your first install, your onboard LED should blink now. Blinking signals that your board has started a soft ap with the ssid "esp32". With your mobile or desktop connect to the WLAN SSID "esp32" and open http://192.168.4.1/setup (if you have not changed the default credentials your username / password is esp32 / esp32 ). You can change the default password in firmware-config.ts by changing the value of keypassword.

On the Setup page you can configure your WLAN settings and an URL to download your JS main script from.

Please note that the script, does not need to have a main function, because its evaluated entirely. That means, to print out "Hello World", you only have to include one line in your script on the webserver:

console.log("Hello world!");

If you need to create your own C/C++ bindings for your JS code, this are the steps to perform:

1. Create a file named project.cpp in the ./main directory
2. Implement the esp32_javascript_main callback function inside this project.ccp:

   #include "esp32-javascript.h"

   extern void esp32_javascript_main(duk_context *ctx)
   {
     // do your own duktape bindings here
   }

See Duktape Programmer's Guide for more information regarding Duktape bindings.

If you need more than this, you can create your own esp-idf component below ./components. Then delegate the esp32_javascript_main function to this component. Additionally you have to set your component name in the top level ./CMakeLists.txt. Refer to the documentation next to the setting ESP32_JS_PROJECT_NAME. See ESP Build System for information on how to create a component with the esp-idf build system.

You can clean the project by executing

    idf.py fullclean

You can erase the persistent flash memory, which will be equivalent to a factory reset, by executing

    idf.py erase_flash

Tested with esp-idf release/v4.2

API documentation

Update documentation by executing

    npm run doc

See source files.