I have been assigned to a project to find the best possible communication between several PCB boards which have microcontrollers for a specific function. I need to have all microcontrollers communicate with the main board which contains a CPU.
I need to send some information from the mainboard to the controllers and receive a response from the controllers. Each controller board is designed for a specific purpose. I don't need to communicate between the microcontrollers, but even if one microcontroller fails to communicate then it won't effect on others. Presently, I need to have six microcontrollers communicate, but in the future more than that. I want to avoid more wired connections between the mainboard and the other controllers (it should be fewer).
The communication should not be affected by the temperature (250 °F (120 °C)) and pressure (high). The distance between the mainboard to the final controller may be more than one meter. Which type of controllers are best? I need to perform some calculations and sensor readings. Each board having more than two sensors. I need to perform some calculations on sensor readings or send values directly.
I am new to this type of project. I have searched for the best communication, but I am confusing which is best. Some people are suggesting me to use CAN communication. If I choose CAN communication, what type of microcontrollers is best? I have attached a simple diagram how it is going to look like as shown below.