Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Can You Wirelessly Transmit Data Pi To Pi

Sat Sep 14, 2019 2:20 pm

Hi Folks
I am new to the Pi and have a question. I am trying to collect and log data on one Pi and send it to another Pi to log and display. I will not have access to the internet where I am colleting the data and can not have a wired connection between them. Is it possible to wirelessly transmit data between the pi's using there onboard WiFi or is it possible to add a wireless USB transceiver to each Pi or maybe use a us a GL-iNet to create a mobile network to pass the data through? I need to keep the setup small 6X6 inch is max size but smaller would be better. Just looking for some opinions and options that I might pursue.

Thank you
Cranky

RattusRattus
Posts: 67
Joined: Sat Sep 29, 2018 11:27 am

Re: Can You Wirelessly Transmit Data Pi To Pi

Sun Sep 15, 2019 5:16 pm

If you have WiFi on your Pis then this is a simple matter of having one Pi configured as the Access point and the rest associate with it.

Take a look at https://www.raspberrypi.org/documentati ... s-point.md

/Andy

Andyroo
Posts: 4465
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Can You Wirelessly Transmit Data Pi To Pi

Sun Sep 15, 2019 5:27 pm

Welcome to the forum,

If you are tight for space then look at the Pi Zero W board.

Thats the smallest practicable board you can use and they are fine for small tasks that are not CPU heavy (still LOTS more oomph than an Arduino).

Range on all Pis depends on the surroundings and you cannot add an external antenna (though you can add a USB Wifi Dongle that has a larger range).

One other option would be to create an ad-hoc Bluetooth network and pass the data that way. I've not seen a WiFi ad-hoc network set up though so the above AP way from RattusRattus will give you the best range.
Need Pi spray - these things are breeding in my house...

Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Re: Can You Wirelessly Transmit Data Pi To Pi

Sun Sep 15, 2019 9:32 pm

Thank you for the welcome. I currently have 2 Pi Zero W's and one Pi 3B that I am working with. I will read through the links and give it a try a little later this evening. Like I say and I am new t this and appreciate all the help I can get. I have found a few Python programs that I am playing with trying to learn a little about Python programming. I have a plan but lack the knowledge to get it to work but it is always fun learning and trying to figure it out.
Always open to suggestions.

Thank you Cranky

Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Re: Can You Wirelessly Transmit Data Pi To Pi

Tue Sep 17, 2019 12:23 am

Thanks Andy I now have that setup and a standalone network. Learned a bit on that one and is was fun. So the next question I am collecting data and saving it to a folder on Pi1 and want it to be able to send that data to a folder on Pi 2 (the standalone network). How I could do that or is it possible to do that?
Thanks
Cranky

Andyroo
Posts: 4465
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Can You Wirelessly Transmit Data Pi To Pi

Tue Sep 17, 2019 12:38 am

Two easy ways I can think of:

1) A program called Samba will allow you to make a directory on the Pi available to other machines.
Once set up, you can use the built in command mv to move files from the local directory to the remote one.
Samba is not too hard to get set up but it will take a bit of work.

2) If you can ssh from one Pi to another, you can use a program called scp to copy files over using a SSH link.
This is documented at https://www.raspberrypi.org/documentati ... ssh/scp.md and is the simplest of the two :D

PS Who’s this Andy guy :?:
Need Pi spray - these things are breeding in my house...

Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Re: Can You Wirelessly Transmit Data Pi To Pi

Tue Sep 17, 2019 2:50 am

I was able to get the Samba installed and can move files form a windows PC to the Pi. That is enough for tonight and want to thank you again for the help. I am sure I will have more questions tomorrow.

Thank you
Cranky

RattusRattus
Posts: 67
Joined: Sat Sep 29, 2018 11:27 am

Re: Can You Wirelessly Transmit Data Pi To Pi

Wed Sep 18, 2019 7:32 am

I am pleased that you are making progress AND having fun

It is always nice when someone posts an answer to a question gets a response (either positive or negative) from the person who posted the question. Obviously nicer when the response is positive :-)

Cheers

/Andy

P.S Andyroo - I guess I am the Andy in Question, I am a little bit further south than you. I'm in Cambridge. I don't blog very often but fwiw https://blog.koipond.org.uk

Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Re: Can You Wirelessly Transmit Data Pi To Pi

Thu Sep 19, 2019 1:14 am

Me again.
Thanks guys for responding to my question. Still having fun and excited to get home form work every night to work on this project.
Next question. I am now able to collect data on my windows PC and save it to Pi 2. That is working great and is heading the way I need it to. Now what I need is the be able to collect the data on Pi 1 and save it to Pi 2. On the windows PC I just go to the file explorer and direct it to Pi 2 how do I do that with Pi 1? Is there away to do this?

Thanks again and much appreciate information.
Cranky

Andyroo
Posts: 4465
Joined: Sat Jun 16, 2018 12:49 am
Location: Lincs U.K.

Re: Can You Wirelessly Transmit Data Pi To Pi

Thu Sep 19, 2019 11:19 am

You could get posh and set up MariaDB (MySQL fork) and write data directly to that from the other pi.

Key things:
What format and size is this data?
What do you want to do with it long term?
Does anything else need to access it?
Need Pi spray - these things are breeding in my house...

Cranky
Posts: 7
Joined: Sat Sep 14, 2019 1:59 pm

Re: Can You Wirelessly Transmit Data Pi To Pi

Fri Sep 20, 2019 3:45 am

Lets say I am trying to collect Temp and altitude data on Pi 1 and transmit it to Pi 2 for the storage or backup. I can not use wires and will need to be wireless transmission of the data. So right now I am able to collect that data and save it to Pi 1. I have Pi 2 setup as it own network/Wifi ( I am sure I am not calling it by the proper name) and can log into it with my iPhone, Windows PC or Pi 1. I can collect the data on a windows PC and save it directly to Pi 2 wireless so that part seems to be working. I just don't know how to save the data directly from Pi 1 to Pi 2 like and am doing with the windows PC to Pi 2. If you think MariaDB will work for this I will give it a shot.

Hope that helped explain a little bit about what I need.

Thank you
Cranky

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