Reducing noise and Implementing multiplexing system

Problem:
A micro-controller needs to take all of the inputs of 12 digital sensors and 6 analog sensors at 5 minute intervals.
1. The raw output from the sensors are now having a lot of noise that needs to be filtered/conditioned with appropriate hardware/software design

2. The output of the 6 Analog sensors (Flow sensors, TDS sensors, Turbidity sensors) are as follows

a. 2 sensors whose output varies between30-35 Hz

b. 2 sensors whose output varies between 12-24 VDC

c. 2 sensors whose output varies between 100-500mA

You will need to design appropriate amplification system wherever needed
3. Due to the limitations of GPIO pins in the board a multiplexing system should be designed that would enable the controller to read all the inputs.


Details:
Microcontroller: You could take your preferred microcontroller

You are required to design/implement a system that could potentially solve all the problems. A brief write-up of the approach you decided was optimum, your reasoning and most importantly proof (screen-shots, pictures and snippets of simulations, source-code etc.) to validate that you made it work should also be attached along.



Any help would be appreciated. Im new to electronics!

So how can we help you? ie what exactly do you need from us,is it help in selecting the right microcontroller,the right sensors,the right interfacing mechanism,what exactly?

Yes basically all the things you mentioned. :/
Ive only started doing electronics and this is a research project for me and I'm not sure where to start from.
If you could point me in the right direction, even that would be helpful

Problem:
A micro-controller needs to take all of the inputs of 12 digital sensors and 6 analog sensors at 5 minute intervals.
1. The raw output from the sensors are now having a lot of noise that needs to be filtered/conditioned with appropriate hardware/software design

2. The output of the 6 Analog sensors (Flow sensors, TDS sensors, Turbidity sensors) are as follows

a. 2 sensors whose output varies between30-35 Hz

b. 2 sensors whose output varies between 12-24 VDC

c. 2 sensors whose output varies between 100-500mA

You will need to design appropriate amplification system wherever needed
3. Due to the limitations of GPIO pins in the board a multiplexing system should be designed that would enable the controller to read all the inputs.

Click to expand...

just 18 DI/DO or AI/AO can be fit in 8051 or any other controller with 24 GPIO so no need multiplexing at all.

For newbi in controller start 8051 or arduino controller.If you want learn the controller then do start with the basic like interfacing switch to learn how to read digital input.use potentiometer for measuring the voltage so you learn the analog input.

And with out brief details about analog sensor its amplification is not possible to design.