RS485 for long distance

Hi Angelo,

I'm studying the installation of your system, but I need to reach relays at "long" distance point (let's say 50 meters, with margin).

Currently, I was testing your project on a desk driving relays on GPIOs, but it is not suitable for my installation.

I think the best way to send commands to this distance is to use RS485.

I was wondering if you already studied this case ?

The idea is to use either a USB dongle

(I have no idea how peripherals connected on USB could be integrated in your project)

or a pi hat (driven through I2C).

If this integration is possible, then it would need a configuration layer with address(and probably a second driver layer to implement required commands of these relays boards)...

I would like to know if you're interested in this integration ?

Another solution for me without modifications of your software would be to add an interface board (arduino ?) to translate GPIO states/edges from your software to RS485 commands. But I think if all can be integrated on the PI board and in your software, that would be a great addition.

PS: links in this post are just samples to illustrate, it needs to be checked for real compatibility

Regards,

Jerome

9 comments

9 Comments

hydrosys4

Aug 14, 2021

Ciao,

Thanks for sharing, this is very interesting. As expected the WiFi at 2.4GHz is quite sensitive to walls and obstructions, anyway in line of sight seems that hundreds of meters are reachable, and this is a good news (Just as note worth to mention, the line of sight in telecommunications usually does not refer to the sight but to the first Fresnel ellipse which should not have obstacles). Also the test with the Dish antenna on router side was very interesting. I definitely did not expect such good results.

In the latest SW version I've developed a solution using the 433MHz (HC-12) transmitter (for sensors) this can exceed above 1km. Below the link.

Long Range Wireless Sensors with HC12, but not LoRa

andrea.milano

Aug 15, 2021

Replying to

Ciao Angelo, I missed the long range wireless post. I just bought a property in south Italy with 3.000sqm of nice soil. This is the perfect solution for distances like 2/300m. Thank you for all your efforts. Indeed.