Noob questions for using multiple HC-12 modules

I've ordered some HC-12 modules to play with from china for my campus temperature monitoring project. From what I can tell, they have different channels, etc, but on the receiving end, they all have to go to a serial device.

So, my question is...am I limited to the number of serial ports an arduino has for the number of HC-12 devices that can talk to it?

So, can a mega have 4 receivers? Would that even work?

Basically I have a bunch of small cabins with no wifi that all are arranged on a cliff edge with one common building below them all. So, I'm trying to figure out the best way to get that temperature down there....

Should I have 10 HC-12s sending (once every 15 mins, and only one hc-12 receiving?)
Do they need to be in 1:1 pairs? Does building 1 need to have a cooresponding dedicated HC-12?
If they are all different channels, how many can you reasonably have operating in the area the size of a soccer(futbol) field before interference becomes a major issue?

Thanks for your time and help. I'm hoping someone else's experience can save me a lot of dumb mistakes.

You can have as many HC-12 transmitters as you like all transmitting to one receiver, but you have to ensure that more than one doesnt transmit at the same time.
You would also need some mechanism to determine which transmission came from which transmitter.
Something simple like each transmitter has a number , and each transmission includes the number.

ie Transmit NXXX where N = transmitter number, XXX is the temperature info.

That sounds fantastic. Thank you!

mauried:
You would also need some mechanism to determine which transmission came from which transmitter.

A good way to do that is to treat one of the Arduinos as the master and it calls each of the others in turn (with the appropriate ID in the message). If a slave receives a message that contains its own ID then it should immediately reply with whatever data needs to be sent. Otherwise the slave should stay silent.

If it is essential for a "slave" to initiate a message (for example because the slaves are asleep most of the time to save power) then you will need a much more complex system to deal with possible data collisions when the messages from 2 or more slaves overlap. Note that the "complexity" is in the logic of the system, not the programming.

...R

Wouldn't it be a good idea to assign different channel numbers to different RC-12 modules?
I am building a multichannel network of HC-12 where all will act as receivers as well as transmitters. Hence I also need help regarding this.
Thanks in Advance.

pramodisha:
Wouldn't it be a good idea to assign different channel numbers to different RC-12 modules?

What does "channel" mean for a HC12?

For the nRf24 modules (with which I am familiar) the channels represent different wireless frequencies. Both the sender and receiver need to work on the same frequency.

...R