Compiling

Flash and memory space on an ESP82XX chip is limited and very valuable. Because of that our precompiled binaries include the most popular features of Tasmota but no build can include all of them.

To include a feature you need (or build completely customized Tasmota) you will have to configure and compile your own version.

First you will need Tasmota's source code (either development or master branch) and a compiling tool.

Compiling Tools~

If you want to modify the code or default settings you can use:

PlatformIO - setup and configure PlatformIO for Tasmota compilation and upload
PlatformIO CLI - how to flash Tasmota using the PlatformIO command line interface on Linux
PlatformIO-Core - automate firmware builds using PlatformIO-Core and flash with esptool
Visual Studio Code - setup and configure Visual Studio Code with PlatformIO for Tasmota
Atom - beginner guide building Tasmota firmware using Atom with PlatformIO plugin
Docker Tasmota - compile from a Docker container using PlatformIO

Online Compilers

Can only create a firmware binary. Use one of the tools to flash it to your device.

Gitpod - compile your own binary in the cloud using Gitpod.
TasmoCompiler - simple web GUI to compile Tasmota with your own settings

Simplest way to compile is with GitPod, requires only a web browser.

Once you have set up the development environment, unzip the source code into a folder.

Customize your build~

The base for your self compiled version has to be Tasmota. Do NOT use a other Tasmota build variant for.

Create a new file in /tasmota folder called user_config_override.h. You can copy the sample file user_config_override_sample.h that is already there and which include some sample definition for coding your own Wifi SSID and pasword inside the Tasmota firmware.

Open the file in chosen development environment for editing.

Enter lines required to enable or disable desired feature. All features and their identifier can be found in my_user_config.h.

Best practice to enable a feature is to use

#ifndef %identifier%
#define %identifier%
#endif

Directives	Description
`#define %identifier%`	enables the feature
`#undef %identifier%`	disables the feature
`#ifdef %identifier%`	checks if the feature is defined in code
`#ifndef %identifier%`	checks if the feature is not defined
`#endif`	closes #if statement

Example: enable blinds and shutters support

#ifndef USE_SHUTTER
#define USE_SHUTTER             // Add Shutter support for up to 4 shutter with different motortypes (+6k code)
#endif

identifier = USE_SHUTTER

check whether USE_SHUTTER is already defined and proceed if it is not
this line copied from my_user_config.h then uncommented, tells the compiler to include (#define) shutter support
close the IF statement from line 1

Example: disable Domoticz support

#ifdef USE_DOMOTICZ
#undef USE_DOMOTICZ                              
#endif

identifier = USE_DOMOTICZ

check whether USE_DOMOTICZ is already defined and proceed if it is
tell the compiler to remove (#undef) Domoticz support
close the IF statement from line 1

It is not recommended to change my_user_config.h, use it only for reference

Save file, compile the custom binary and flash it

Note

There are limits to how many features can be included! If you go overboard code might not compile due to features conflicting or might not be able to be flashed if it exceeds ESP8266 limits.

Defining multiple custom firmwares~

You may want to generate multiple custom firmwares such as one for switches/relays, one for sensors, in a similar way as Tasmota provides different binaries. This can be achieved very simply.

Rename the file platformio_override_sample.ini as platformio_override.ini. Do not change anything inside.
Create a file platformio_tasmota_cenv.ini like the sample below. This will allow you to define your own binaries. cenv stands for Custom ENVironment where an environment is a specific binary to generate.
In your user_config_override.h you can create sections with specific settings for each type of firmware. SSID and MQTT can be outside of the section so they apply to every binary.

Sample `platformio_tasmota_cenv.ini`

; *********************************************************************
[platformio]
; For best Gitpod performance remove the ";" in the next line. Needed 
; Platformio files are cached and installed at first run
;core_dir = .platformio

; *** Build/upload environment
default_envs =
; *** Uncomment the line(s) below to select version(s) that will be build
;     by default. Commented versions can still be build individually from
;     VSCode or command line
                tasmota-foo
                tasmota-bar
                tasmota32-foo
                tasmota32-grizzly

; *********************************************************************
; Common section can override global parameters for all builds
[common]

; *** Upload Serial reset method for Wemos and NodeMCU
upload_port               = COM4

; *********************************************************************
; This section show how to create 2 alternative binaries : tasmota-foo.bin
; and tasmota-bar.bin. Those binaries are derived form tasmota.bin and 
; customization is defined in user_config_override.h 
; Those binaries are for ESP8266
; The name after the env: tag will give its name to the binary
[env:tasmota-foo]
build_flags = ${common.build_flags} -DFIRMWARE_FOO

[env:tasmota-bar]
build_flags = ${common.build_flags} -DFIRMWARE_BAR

; *********************************************************************
; Similar exemple for ESP32
; Note that you must explicitly state that they derive from `tasmota32`
[env:tasmota32-foo]
extends = env:tasmota32
build_flags             = ${common32.build_flags} -DFIRMWARE_FOO

[env:tasmota32-grizzly]
extends = env:tasmota32
build_flags             = ${common32.build_flags} -DFIRMWARE_GRIZZLY

Sample `user_config_override.h`

#ifndef _USER_CONFIG_OVERRIDE_H_
#define _USER_CONFIG_OVERRIDE_H_

// force the compiler to show a warning to confirm that this file is included
#warning **** user_config_override.h: Using Settings from this File ****

// ***********************************************
// ** Global settings for all binaries ***********

// -- Setup your own Wifi settings  ---------------
#undef  STA_SSID1
#define STA_SSID1         "YourSSID"             // [Ssid1] Wifi SSID
#undef  STA_PASS1
#define STA_PASS1         "YourWifiPassword"     // [Password1] Wifi password

// You can also define your IP settings or your MQTT settings

// ***********************************************
// ** Firmare specific settings ******************

// -- Options for firmware tasmota-foo and tasmota32-foo ------
#ifdef FIRMWARE_FOO
    // This line will issue a warning during the build (yellow in 
    // VSCode) so you see which section is used
    #warning **** Build: FOO ****
    // -- CODE_IMAGE_STR is the name shown between brackets on the 
    //    Information page or in INFO MQTT messages
    #undef CODE_IMAGE_STR
    #define CODE_IMAGE_STR "foo"

    // Put here your override for firmware tasmota-foo
    #define USE_I2C
    #define USE_SENSOR_FOO  // Beware this doesn't exist !!!

#endif

// -- Options for firmware tasmota-bar ------
#ifdef FIRMWARE_BAR
    #warning **** Build: BAR ****
    #undef CODE_IMAGE_STR
    #define CODE_IMAGE_STR "bar"

    // Put here your override for firmware tasmota-bar

#endif

// -- Options for firmware tasmota32-grizzly ------
#ifdef FIRMWARE_GRIZZLY

    // If these settings are only for ESP32, you can check these
    // are used only when building for ESP32
    #ifndef ESP32
    #error *** This setup of for tasmota32 only ***
    #endif

    #warning **** Build: GRIZZLY ****
    #undef CODE_IMAGE_STR
    #define CODE_IMAGE_STR "grizzly"

    // Put here your override for firmware tasmota32-grizzly

#endif

#endif  // _USER_CONFIG_OVERRIDE_H_

Compiling

Compiling Tools~

Online Compilers

Customize your build~

Defining multiple custom firmwares~

Sample platformio_tasmota_cenv.ini

Sample user_config_override.h

Sample `platformio_tasmota_cenv.ini`

Sample `user_config_override.h`