Mervis on Unipi 1.1 & Lite

Unipi 1.1

The Mervis OS image can be written to an SD card using the open-source BalenaEtcher tool (for Windows OS) and then run on Unipi 1.1/Lite.

You can download BalenaEtcher from official web pages.

Flashing the OS

The next step is to download the latest version of the image of the OS you selected. An archive with pre-assembled OS is available on webpage: Mervis OS for Unipi 1.1/Lite.

Caution!
Extreme caution is essential when choosing a disc. Selecting the wrong storage medium could result in data loss on a storage other than the desired one.

Note:
For trouble-free Mervis OS usage on Unipi 1.1/Lite, you will need storage with capacity of at least 2 GB.

We always recommend using industrial SLC SD cards.

Flashing OS image from a file

When running BalenaEtcher, there are three options in the main menu, selecting the first Flash from file will bring up a file explorer to select a disk image. This disk image can either be directly in *.img or *.raw format, or it can be packaged in a ZIP archive.

After successful selection of the OS image, the next option Select target is possible to select a suitable storage. When selecting, please note the caution in the introduction of the article.

Flashing the OS image to storage will start after clicking on Flash!

Flashing OS image from an URL

BalenaEtcher also allows you to upload an OS image directly from a URL link to an .img or .zip file (with an OS image). In the main menu there is a choice of Flash from URL.

The field labeled Enter a valid URL (under the heading Use Image URL) is used to enter the address of the OS image.

OS image URL can be obtained by right click on “Download” button and selecting Copy Link from context menu.

If the image source requires a login credentials, a username and password can be entered in the Authentication section.

The selection of the suitable storage to which the OS image is to be written is possible by checking the checkbox. When selecting, please note the caution in the introduction of the article.

Flashing the OS image to storage will start after clicking on Flash!

Before running the OS on a Unipi device

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Note:
After finishing the flash, or after the storage drive is reinserted into the PC, Windows OS may detect it as a new storage device that it cannot recognize and may request formatting. Close the formatting prompt by clicking on Cancel.

The Windows OS may also display notification that the storage is unavailable. This message can be ignored.

Inserting password for SSH

It is necessary for the first login to insert a user password onto the SD card. For further information see Passwords.

Here are the instructions for setting the user password:

Choose a new password and using the tool below generate hash from your password
Open the SD card in file explorer
1. Create a new file named PWD_HASH_USER in the root directory of the boot FAT32 partition. It is important the file has no file extension, do not add .txt at the end. Open the newly created file in a text editor and paste the generated hash
2. Download and save the file with hash to the root directory into the boot FAT32 partition of the SD card
Eject the SD card and insert it into the device
After the device starts, the new password will be set. It will now be possible to log in over SSH with the password entered in step 1.

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Note:
This process can only be done once, if the device is in factory settings (newly flashed SD card). If the user password was previously set on the SD card this process will not work.

Hash generator

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Note:
If you are offline, this tool can also be found in the FAT32 partition of the Neuron and Unipi 1.1 image.

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Note for Debian 12 and older:
If the OS image has been successfully flashed, the storage will be identified with the name boot when re-inserted into the PC.

If the Mervis OS has been flashed on the storage, there is one last step possible: enabling SSH. SSH can be activated directly in the Mervis IDE by changing the RunTime configuration, see section Uploading a RunTime configuration (RT) - unipi specific. For non-Mervis OS, the SSH connection is enabled by default and does not need to be enabled in this way.

After SSH is enabled, you can connect with, for example, Putty.

Running the OS on a Unipi device

At this moment, the OS is ready on a storage (with SSH enabled). After removing it from the computer, the storage can be inserted into the Unipi device.

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Attention:
Disk storage can ONLY be inserted when the device power supply is unplugged!

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Note:
Insert the SD card back side up into the slot (i.e. the gold connectors towards the technician). Plug the power supply in.

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Attention:
Booting the device with the newly flashed OS will take a little longer - about 3 minutes. This is due to the necessary configuration of the OS.

Installation of Mervis

Download the latest version of Mervis from our download section and run the installation package.

The installation process displays the welcome screen, which you can confirm by clicking on Next.

In next dialog, you have to confirm the License agreement and click on Next

In next dialog, we can select parts of Mervis for installation. The IDE is the editor, in which we will create and debug programs for Unipi unit. The Windows RT is a simulator of a unit, if you don't have one. Typically, you will need only the IDE.

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Note:
In older Mervis version, there was also option for installing HMI editor. In current version, the HMI editor has been merged into IDE.

Last two dialogs are just for confirmation of the installation process and finishing it. Just hit Install and then Finish.

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