I need 3MQ sensor output analog value transfer to esp32 chip using RJ45 port, but i should use only 2 line of RJ45 port to data transfer. how i will it using Arduino. I think following step need follow to it. firstly analog output of sensor signals convert to digital. secondly transfer using protocol finally DAC
You will need an additional controller to convert a sensor signal from analog to rj45.
Why don't you want to connect sensor to esp32 directly, to analog input pin?
i need create environment monitor project therefore i need check environment condition different places using sensor panel. can you idea how it do ( data transfer system)
If your sensors are situated distant one from the other - you need a separate controller for each. It can be an ESP32 boards, which you then connect via Wifi, for example
can i use ATMEGA328 it
Yes, you can, using the RJ45 as link
but can i use only 2 data line of rj45 port for 4 sensor
Rj45 is just a connector type.
What protocol do you intended to use on RJ45 ?
not idea about it to me
What about modbus? It use only two data lines and can connect multiple devices with same bus.
You can find a lot of examples in the net, try google something like "arduino modbus examples"
Modbus is a protocol that can be used on an RS485 interface and devices could be connected using RJ45 connectors. RS485 can connect several devices using just 2 wires. Distances can be upto about 1km and data rates upto low Mb/s.
How to multiplex and demultiplex the output of 4 sensors using atmega328. Should an encoding method be adopted? Can ADS1115 be used?
Did you read something about modbus? Reading your question i afraid no...
Sorry, good luck to your project
DHT11 outputs data in digital format, not I2C. Simply connect the DHT11 to one of the digital pins.