We're in the step of making design decision for a wireless mesh network of individual sensors which is going to be low cost.
At first research I decided to use MQTT for application layer and global ZigBee protocol stack for other layers beside an AVR MCU for our sensors.
But if using a ZigBee compatible CC2530 transceiver costs about 12-14$ then it's not cost-effective!
And also there's one more difficulty, and it's about the ZigBee hub!
So what's your suggestions?
Can we do this small-to-medium scale mesh with simple ESP8266 and other network layer protocols?