2-Bullet Tuesday - Edition #64

  • administrators

    Welcome back to 2-Bullet Tuesday, where we’ll share useful tips and awesome stuff sent in by Omega2 users all around the world. Check out creative projects and tutorials that will supercharge your IoT development!

    Favorite Project

    RFID Access Control

    This week our favorite project is an RFID access control system by Onion’s own Pavel Metrokhin! The project uses the recently released RFID & NFC Expansion to scan RFID tags and triggers an electronic lock to open when a trusted tag is scanned.

    rfid access control project

    The project uses an Expansion Dock, Relay Expansion, OLED Expansion, RFID & NFC Expansion, a 12V Solenoid Lock and a 12V Power supply. The Omega holds a JSON list of trusted RFID tag IDs and everything else is controlled by a Python program that constantly scans for RFID/NFC tags and triggers the lock when a trusted tag is scanned.

    The Hackster post covers all the steps and will guide you through the hardware setup and software installation. You can find the source code on our RFID-Access-Control GitHub repo.

    So that’s that! A single command to run and voila, you have an electronic lock secured with your RFID tag. Now you just have to find something to keep safe!

    Check out the Hackster Post

    Omega Tip

    Monitor your Battery Level with OnionOS

    Last week, we released OnionOS, our all new web-based, graphical user interface. This week, we’d like to introduce a new OnionOS App: the Battery Level Monitor, for use with the Power Dock 2.

    battery level monitor app

    The App displays the latest battery voltage and a chart of the battery level for the last 24 hours - allowing you to visualize your battery usage. Once a minute, the App will talk to the Omega and grab the latest available readings. Right after the Omega boots, it will start collecting battery level readings, so the app will always have data to display.

    Make sure to note that you’ll need to be using the Power Dock 2 to get the battery level readings. If you’re in need of a LiPo battery to use with your Power Dock 2, our friends at Sparkfun have quite the collection.


    To install the Battery Monitor App on your Omega, run the following commands:

    opkg update
    opkg upgrade power-dock2 oos-app-nfc-exp onion-os
    opkg install oos-app-power-dock-2
    /etc/init.d/power-dock-2 start
    /etc/init.d/rpcd restart

    If you’re thinking, “hmm that’s pretty clunky for adding a new app”, we’re with you 100%. We plan to spend some time improving this flow in the short-to-mid term, stay tuned!

    As always, let us know what you think and if you spot any issues! Happy hacking!


    Make sure to subscribe to 2-Bullet Tuesday to get technical tips about using the Omega, projects created by Omega2 users, and, occasionally, special promotions for the Onion Online Store sent directly to your inbox!


  • Hi Lazar,

    did you already test if the RFID & NFC Expansion is able to work with the MiFare DESFire EV1 cards?
    I ask cause many other breakout boards do not work with this type as the antennas are not efficient enough...

  • administrators

    @Peter-Moellers so far we've only been testing with Mifare classic and ultralight. We'll make sure to get ahold of some DESFire EV1 cards and let you know how it goes!

  • @Lazar-Demin Thank you for your support. I am very much looking forward to the result.

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