Frequently Asked Questions (FAQ)

What is Josev?

Josev stands for β€œJoint Operating System for Electric Vehicle Charging” and is an off-the-shelf, embedded operating system (OS) that, when implemented on your hardware, elevates it with OCPP and ISO 15118 functionality.

What is included in the Josev software stack?

Josev includes native support for OCPP 1.6J, 2.0.1, both Core & Advanced Security (additional modules on request). On ISO15118, it includes -2, -3, and -20. It also includes an EXI codec and MQTT message broker.

What is the EXI codec?

The EXI codec is an encoder/decoder required to exchange ISO 15118 messages between the EV and the station. It is a small but crucial part of ISO 15118, without which we can’t send or receive messages to the EV.

What is the MQTT Message Broker?

The MQTT message broker handles communication between our internal services. It exchanges information between our 15118 and OCPP modules (e.g., Plug and Charge token for authorization) and interacts with customer hardware, such as meter readings.

What is the Josev API?

The Josev API defines the messages we send or receive via the broker. MQTT is the medium, and the Josev API is the content of the messages. The API can be provided in C/C++ bindings of our Python-based Josev API.

Can you buy the individual components of Josev separately?

Yes, you can buy the OCPP, ISO15118, and EXI codec separately. See here for full details.

Do we get the source code when we buy Josev?

By default no, but schedule a call with us to discuss your needs.

What programming language is used on Josev?

Josev is built over Python and Rust as follows:

  • ISO 15118-2: Rust

  • SLAC: Rust

  • OCPP 1.6: Rust

  • OCPP 2.0.1: Python (moving to Go lang soon)

  • DIN 70121: Python (moving to Rust soon)

  • ISO 15118-20: Python (moving to Rust soon)

We are converting the entire ISO 15118 module to Rust, with ISO 15118-2 already in Rust.

How do you distribute Josev?

We generate an executable with all needed dependencies, compiled to your desired target: armv7, armv8, x86_64, x86. The executables are provided via a secure download.

Can Josev run on any embedded device?

Josev can run on any embedded device that runs Linux and contains a PLC (PowerLine Communication) module. It was not designed for bare metal targets.

Are there minimum requirements to run Josev?

Yes, first of all Josev is not designed for bare metal targets, so it needs an Unix OS based system. Further than that, these are the requirements depending on the flavor:

🐍 Python Bundle Requirements

  • OS: Linux-based

  • RAM: 250 MB (peak)

  • Disk Space: ~45 MB

πŸ¦€ Rust Binaries Requirements

Target

CPU [%]

RAM [MB]

Disk Space [MB]

armv7 (NXP 6ULL)

7 - 10

~20

5.3

armv7 + openssl

7 - 10

~20

7.3

CPU usage can peak over 50% during Authorization loop scenarios but stabilizes around the values in the table.

Can I customize the code stack for my business purposes? What is the license provided by Josev?

Josev comes with an Apache 2.0 license, allowing modifications and commercial distribution, provided:

  • Recipients get a copy of the license.

  • Modified files carry prominent notices.

  • Retain all copyright, patent, trademark, and attribution notices in the source form.

  • Include readable attribution notices within derivative works.

We are designing our own controller, could you recommend any PLC modules that we could use with Josev?

Yes, recommended PLC modules:

We specifically recommend Qualcomm or Lumissil.

Do you offer some kind of hardware or turnkey solution with Josev?

Yes, we have partnered with Chargebyte, providing the β€œCharge Controller C” board tailored for eMobility needs. More info here.

How can I see Josev in action?

We offer a 1-month trial, including:

  • ISO 15118-2: AC, DC, PnC

  • ISO 15118-20: AC, DC, Bidirectional, PnC

  • DIN 70121

  • OCPP 2.0.1

  • Free access to the Switch EV backend platform during the trial

What are the limitations of Josev demo?

The demo includes all regular and production features but is limited by:

  • Charging sessions terminate after 10 minutes.

  • Josev connects only to the Switch EV backend platform.

Is there any documentation that can guide me through Josev?

How do you handle bugs with Josev?

Customers get access to our GitHub private page for ticket creation for questions or bugs. We also provide Yocto recipes for downloading and adding Josev to your custom OS.

How do updates work for Josev?

We push and update versions of Josev internally and notify customers, allowing them to control the best time for hardware updates.

Have you implemented Josev on both AC and DC?

Josev has been implemented on AC. We are testing High Powered DC Chargers and expect completion by mid-2024.

How does the Josev trial work?

Upon interest, a Switch expert ensures you get the right product. You receive instant download access or pre-configured charge controllers in 3-5 days (~Β£400). The trial is limited to 10 minutes per charging session.

If successful, we send a license agreement for unlimited access and support. Feedback is always appreciated.

When on the Josev free trial, will customers be able to test with their own charge controllers?

Yes, we provide executables/binaries for testing, requiring the target architecture information.

Can Josev support 2 charge guns?

On other words, 1 OS with 2x EVSE’s on the same charger - can this be supported? Yes, Josev supports multiple EVSEs on one operating system.

Have more questions?

If you have any other questions that have not been covered by this document, please feel free to contact the EcoG team at josev.support@ecog.io.