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I'm student from Czech and currently I'm working on a meteostation project. I've got an arduino set up, with plenty of weather sensors, as well as WH1080 sensors connected. But right now, I'm only able to read the data via serial port on a computer with arduino IDE or show it on my 20*4 display. As the distance where I need to transfer the data once I finish this is unsuitable for wireless receivers, I found these MAX 485 modules on ebay for cheap.

max485 module

I quickly got 2 pieces, as well as 5v-3.3v logic level shifter, as I was concerned about different level on the Rpi. I don't know much about Pi's and their pins, as the only thing I've used with them is a DS3231 real time clock module.

Now, the thing I'm trying to achieve is this - I want to be running a bunch of sensors at roof of our house, and have the arduino send the data to Raspi over the rs485 (on request? as the sensor loop would be like 10-15min so maybe communicate on interrupt?) What I'm planning to do with the data on the raspi would be running a software like WeeWx or wfrog to process them and possibly render a local website, that I could make public as port forwarding (i have public IP).
However, there are few questions I have, hopefully its not too much to ask

  1. How would the wiring look like? I was unable to find any dumb-proof tutorial online, as I don't know whether or how to use the logic level shifter.

  2. If I can read the data over serial port, would it be just a plain text (as shown on PC in arduino ide serial monitor), or has each value its address that I could then easily assing to a variable then being used to process the weather data?

  3. If I'm completly wrong in something, or there's some completly different way how theese things are being done by more experienced people, I'd love to hear some suggestions.

  • Hello and welcome to the Raspberry Pi community on Stack Exchange. I think you may be trying to ask too much in a single question here! You may get more useful responses if you can try and break this up into smaller parts which can be more easily dealt with one-by-one. Also, those smaller bits could already have answers here - try using the "Search Q & A" box in the top right of the page for words associated with your questions... I am sure there are questions (and answers) about this sort of "monitoring a lot of Arduinos units from one RPi" and "RS-485" and multiple temp. sensors here! – SlySven Jan 30 '16 at 22:15
  • I know it won't help much, but having done this before I can definitively say that this is possible. The hardest part for me was breaking out the serial data into usable pieces, and getting some sanity checks in to make sure the data wasn't corrupted in transit. Good luck! – Butters Jan 10 '17 at 19:06
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Use theese links, and happy DIY'ing! Feel free to ask questions :

UPDATE: Wiring schema

The wiring looks like this, all the rest is better starting with a manufacturer's manual on the 2nd link. One piece of advice - look for ttyAMAx intefaces BEFORE and AFTER plugging your device - the default number 0 and corresponding name /dev/ttyAMA0 may be not always the same, i.e. having it on /dev/ttyAMA1 is totally OK - it depends on many factors

  • Could you add more content to your answer, such as explaining how to use the RS485 Serial Module link you posted? Just linking to resources means that if links die, your answer dies. – Deleuze Feb 13 '17 at 10:10
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    Thanks! If you wonder why this came up now, your answer was flagged lately after the question was bumped to the first page... – Ghanima Jul 16 '17 at 21:07
  • OK, may I know the specific reason about the flagging? What exactly was wrong with my answer? It links th the pinout of RPi and second link is a chip application Wiki which covers exactly the case of the Asker. – Alexey Vesnin Jul 16 '17 at 21:11
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    Well, the idea is to have answers stand on their own, with external links for reference only. So fleshing out an answer that it remains helpful in case the links die is the way to go. See also policy regarding informationless link-only answers. – Ghanima Jul 16 '17 at 21:16

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