I would like to build a device to monitor few chemicals (CO, NH3, H2S) and particulate (PM2.5 and 10) in the air. I have been looking online for related sensors and I found that the MQ-X series (CO=MQ7, NH3=MQ136, H2S=MQ136) and SDS011 for PM might be suitable for my case.
In the tutorial (https://tutorials-raspberrypi.com/configure-and-read-out-the-raspberry-pi-gas-sensor-mq-x/) MQ-2 sensor only is being used. Other two components are Analog-to digital convertor (ADC) (8 ports) and Logic-level convertor (LLC) (to cut down the voltage 5 to 3.3).
Would it be possible to build a multi-sensors device with a single a pi? Would I need the same ADC and LLC mentioned in the tutorial only? Which version of pi would you recommend? Sorry for the many questions but I am quite new with raspberry pi and hardware in general. Thank you