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About Plošná ryba

Where the name comes from

Plošná ryba is a Czech pun. A plošný spoj is a printed circuit board. A ryba plošná is a flatfish, the flounder, which lies flat on the sea floor. Our devices are flat boards in small boxes that sit quietly in the garden, under a beehive or in a water tank and measure things. The name stuck.

A family of fish

Plošná ryba is part of a small family of brands:

  • Nafukovací ryba (Nafukovací ryba s.r.o., literally "pufferfish") is the parent company.
  • Hranatá ryba ("square fish") prints plastic cards. You can find it at www.hranataryba.cz.
  • Plošná ryba is the electronics brand: devices for Home Assistant.

Each fish does something different, but they all belong to the same small company.

Why open hardware

Home electronics should last for years. We have all seen smart devices stop working when the vendor shut down its servers, or become unrepairable because there were no schematics or firmware. We do not want to build that.

So we publish everything: schematics, PCBs, enclosure models, firmware and documentation. Firmware is MIT, hardware CERN-OHL-P-2.0, docs CC BY 4.0. The devices run ESPHome, so you can modify, extend or repair them yourself, even if we are no longer around. No cloud, no app. Your data stays at home and the devices work without internet.

Made in the Czech Republic, in small batches

We design in the Czech Republic and build in small batches. We print the enclosures ourselves and assemble and test every unit before it ships.

Small batches mean no warehouse full of boxes. That is why we sell on pre-order and ship once the first batch is made. CE testing is planned before regular sales start. We ship to Czechia and Slovakia via Packeta, other EU countries on request.

Who we build for

Mainly Home Assistant users who want a finished, reliable device without giving up the option to tinker. Beekeepers, gardeners with rain water tanks, households on dynamic electricity tariffs. And the ESPHome and Home Assistant community outside the Czech Republic, which is why these English pages exist.

Contact

Write to info@plosnaryba.cz. We are happy to answer technical questions, hear ideas for new heads and receive bug reports, in English or Czech.