A temperature controller for a piglet farm. Each room of the farm has up to 30 "nests". A controller will control up to 2 nests. All the controllers in a room will be comanded by a central unit at the door of th room.
It will control the temp using pwm like AC phase shifting. An optocoupler will detect each zero-crossing on the mains AC line and will trigger the triac after a delay dependent on the duty cycle required. This duty cycle will be calculated by a PID control in software.
Dependending on the age of the piglets, they need diferent temperature(they are 21 days in the farm before being transferred to a fattening farm). This temps will be stored in a table.
Through the central unit, the farmer will set the temps for the table and check the diferent nests temp.
This wil be a prototype with 2 controllers (probably esp8266) and a central unit (hopefully the unit you will give to me).
The central unit wil act as an wifi AP for the other controllers.