Hi everyone
I am new here
I need help in signal transfer
i am using arduino and MH z16 sensor with PWM output to communicate
but i had found that it is not working on distance of 500 ft
I am using pre insulated wires of 2 pair for communication
Thank in advance
waiting for response

 

Welcome to AAC!

Here are a couple of solutions:

1) Put two small microcontrollers at both ends of the cable and drive the cable with RS-485 transceivers.

2) Buy an off-the-shelf cable extender such as this.

 

You probably have problems with the ground reference.

Assuming you have the sensor powered over the cable, 85 ma X 12 Ohms (assuming 500' of #24 AWG) gives you 1 volt of drop in the ground leg alone, which will make recovering the signal at the other end difficult.

You will have better luck making it a current loop, driving an opto isolator at the receiving end.
Assuming you are using the PWM output.

Send 12 volts power down the cable, with a 5V regulator near the sensor to make it bulletproof.

 

Plastic fiber optic link -

https://www.digikey.com/en/supplier...MIuYGhgauK3AIVhVd-Ch3e5AD7EAAYAiAAEgKGKvD_BwE

https://www.digikey.com/product-det...MIqc_TxquK3AIVhqDsCh3b7wRuEAAYASAAEgIemfD_BwE

https://www.digikey.com/product-det...MIp66C7quK3AIVh8hkCh36fwQ2EAAYASAAEgKZCPD_BwE

Regards, Dana.

 

Thanks
If Signal is droping then how we can resolve it.

 

Thanks
Can you please guide how can i use it with my setup
I am using PWM with Arduino
Sensor - MH Z16
Arduino - UNO R3

Plastic fiber optic link -

https://www.digikey.com/en/supplier...MIuYGhgauK3AIVhVd-Ch3e5AD7EAAYAiAAEgKGKvD_BwE

https://www.digikey.com/product-det...MIqc_TxquK3AIVhqDsCh3b7wRuEAAYASAAEgIemfD_BwE

https://www.digikey.com/product-det...MIp66C7quK3AIVh8hkCh36fwQ2EAAYASAAEgKZCPD_BwE

Regards, Dana.

 

I agree that your probably much better off using RS485. Here https://www.serialcomm.com/serial_r...ter/rs485_to_5v_ttl.product_general_info.aspx is a TTL to RS485 gizmo. You need termination resistors ate each end.

Some systems might add power, For instance Carrier uses RS485 combined with 24 VAC in half duplex, but they are not going 500 feet.
RS485 allows like 32 sensors. You have to use terminators ate each end.

Read the RS485. It's rough. I set up only one system and getting the polarities right was troublesome. https://en.wikipedia.org/wiki/RS-485 and others.

So, you could send a DC signal as well as RS485 data, but put a DC-DC converter at the sensor end.

RS484 is multi-drop, so 32 sensors could be supported.

 

Your sensor is using PWM as its output, so its a simple one way link
Tx from sensor to Rx at Arduino. So fiber optic transmitter at sensor
end, fiber optic receiver at Arduino end.

And of course code in Arduino to measure pulse width of incoming
PWM signal in order translate to ppm using equation in datasheet.

https://forum.arduino.cc/index.php?topic=426886.0

https://www.arduino.cc/en/Reference.PulseIn

Regards, Dana.

 

Show your schematic of how you have it connected now, that might lead to a simple fix.

 

How about converting the voltage PWM to a current PWM as in a 4-20mA current circuit? No voltage drop problem. Maybe something like this only at the 5v level and a convenient current (post #2):

https://www.google.com/url?sa=i&rct...aw3_E88lxM5XaOzJt_s0dQZ9&ust=1531063820272382

Ken