Iot relay using cardano node

I’m currently develop iot app trough node red…the only draw back that i see is that we need every time a private broker to relaying the machine msg to another. How we can use cardano blockchain as a decentralized multi purpose broker or a relay node. If there possibility to create an block/slot appendix that can act as msg tranciever to and fro iot machines.

As i see now…with actual mainet we have to pay each time we send metadata to another wallet

For ex: i ll send temperature, pressure as metadata from wallet1 to wallet2…then i ll send again in 10 seconds…that lll requires fee…and from 10s to 10s will be a lot.

It will not work , but i need still the descentralised node of cardano…maybe there is a possibility to be exempted…and the msg after being received should be deleted for preserving the block chain

One another idea is to create brand new shelley blockchain and do some tweaking with iot, but this will be another testnet so…