Modbus RTU Slave


Does Zerynth have any example of Modbus RTU on ESP32. I have requirement of both wired and wireless communication in my project. I can see only master example. I have read in the forum that, same libraries could be used to implement Modbus RTU slave also.

Any suggestions or inputs on Modbus RTU slave implementation would be great help.


Hi @nkb
Currently, Zerynth Modbus library supports master role, slave role is not yet supported.
it is on our pipeline but I cannot give an exact date for it.

the library is open-source, so you can access and edit it for you project and support the slave role.
the library can be found at .zerynth2/dist/r2.6.0/libs/official/zerynth/modbus

Are you developing a DIY project or a product/PoC? :thinking:

Let me know if you need more help.

Currently, I am at PoC stage. I will be moving to Production.

Cool, Let me know if you need custom software development services from Zerynth to support features/devices…
also when you move to production, there some features that will be interesting for you, like mass programming , watchdog timers…

if you need more help, Let me know.

Yes I would love to know the cost structure and more details. I need mass programming.

These are some general information on the Mass programming for small to medium batch of devices, for large batches we can arrange custom service for you.

As for the cost structure, have a look at the Zerynth OS license pricing:

For more information related to pricing, mass programming, device support …
feel free to contact the Sales team on :