# Update Methods

There are three ways to update (flash) MULTI-Module firmware.  In order of convenience and ease, they are:

* From a compatible radio running erSkyTX or OpenTX
* Using Flash Multi
* Using the Arduino IDE to compile the firmware from source and flash it

Updating from the radio requires the MULTI-Module to have the MULTI-Module bootloader installed.  Most modules have this already, with the exception of internal modules in early T16 Pro radios.

{% hint style="success" %}
It should be possible to update the MULTI-Module from the radio if the firmware version on the module is **v1.2.1.85** or newer.
{% endhint %}

Modules with older firmware need to be updated once using Flash Multi, which will automatically install the bootloader during the update process.  See the [Bootloader ](https://www.multi-module.org/advanced-topics/bootloader)page for more information.

## Flashing From the Radio

MULTI-Module firmware can be updated directly from a radio running erSkyTX, OpenTX, or EdgeTX.

Updating from the radio requires the MULTI-Module to have the MULTI-Module bootloader installed.  Most modules have this already, with the exception of internal modules in early T16 Pro radios.

It should be possible to update the MULTI-Module from the radio if the firmware version on the module is v1.2.1.85 or newer.  Older firmware needs to be updated once 

### erSkyTX

{% hint style="info" %}
The erSkyTX bootloader v2.9 or newer is required in order to update the MULTI-Module firmware from erSkyTX
{% endhint %}

**Step 1:**  Download the appropriate firmware file from the MULTI-Module firmware releases

**Step 2**:  Copy the firmware file to the FIRMWARE folder on the radio's SD card

**Step 3**:  Switch the radio on in bootloader mode (hold the two horizontal trims in towards the center)

**Step 4:**  Choose **Run App** then launch the **FlashMulti** app

**Step 5:**  Choose the file type **BIN**

**Step 6:**  Choose the firmware file to flash, long pressing the ENTER button to select it.

**Step 7:**  Long press ENTER again to flash the file to the MULTI-Module

**Step 8:**  When flashing has finished, switch the radio off then  on

### OpenTX and EdgeTX

{% hint style="info" %}
OpenTX 2.3.3 or newer is required in order to update the MULTI-Module firmware from OpenTX.
{% endhint %}

**Step 1:**  Download the appropriate firmware file from the MULTI-Module firmware releases

**Step 2**:  Copy the firmware file to the **FIRMWARE** folder on the radio's SD card

{% hint style="warning" %}
OpenTX and EdgeTX radios with small LCD screens (e.g. Taranis Q X7, RadioMaster TX12) will not display files with names longer than 32 characters when browsing the SD card from the radio menu. You may need to rename the downloaded file before you can access it on your radio.
{% endhint %}

**Step 3**:  Switch the radio on normally and use the radio menu to locate the file on the SD card

**Step 4**:  Highlight the file and press the **ENTER** button (or the roller)

**Step 5**:  Choose **Flash internal module** or **Flash external module** as appropriate

![Flash External MULTI-Module](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-LyV7DyOI5rGlDADpOZk%2F-LyVAlvnH9ZdU-HQ3l2L%2Fflash_external.png?alt=media\&token=da2f6abe-3177-45d5-adf4-e183acb4af85)

{% hint style="success" %}
OpenTX/EdgeTX will validate that the file you are trying to flash is suitable for the module you are updating by checking a signature embedded in the MULTI-Module firmware file.  It will give an error if the file does not match the expected configuration.
{% endhint %}

![MULTI-Module Flash Progress](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-LyVAqbW9ucPCaB_R2w0%2F-LyVCB565cVeVCaU9L_5%2Fmodule_flashing.png?alt=media\&token=6e7af2d2-5f27-44f5-a341-8fe8350e803b)

{% hint style="info" %}
A **No Sync** error means that the module you are trying to flash does not have the MULTI-Module bootloader installed, and the module must be updated once using Flash Multi before you can update it from the radio.  See the [Bootloader](https://www.multi-module.org/advanced-topics/bootloader) page for more information.
{% endhint %}

## Flash Multi

Flash Multi is an application written specifically for updating the firmware on a MULTI-Module.  It works with all MULTI-Modules.  There is a Windows application and a shell script for Linux and Mac.

![Flash Multi](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-MFH9LI7CxhlhSMbF9Us%2F-MFH9TKWjyIQxIZ_MV0C%2Fflash-multi.jpg?alt=media\&token=6302a8ff-7c98-4e98-b90f-26b251b11f88)

More information and full instructions are available in the Flash Multi repository on GitHub:\
<https://github.com/benlye/flash-multi>

## Compiling and Flashing

The Arduino IDE can be used to compile the MULTI-Module firmware from the source.  Once the firmware is compiled the Arduino IDE can also flash it to the module via the module's USB port or a USB-to-serial adapter.

See the Compiling the Firmware page for more information about compiling MULTI-Module firmware.

{% content-ref url="../../advanced-topics/compiling-the-firmware" %}
[compiling-the-firmware](https://www.multi-module.org/advanced-topics/compiling-the-firmware)
{% endcontent-ref %}