Arduino Uno + LoRa RFM95

Hello there
I'm a real novice in Arduino and I have been given the task to emit something with one Arduino Uno + RFM95 and then receive the data with one Keyestudio ( Identified by the Arduino IDE as an Arduino Mega ) + Another RFM95

So I've been looking for a long time now and I can't find how to wire all this.
I found a bit of code to put on the boards by installing RadioHead libraries but that's all

Could someone help me ?
Thanks

There are Server and Client example programs in the Radiohead library.

These examples use the RH_RF95.h library file.

The RH_RF95.h library file contains the details of the connections needed.

Oh I didn't know that !
Thanks a lot !

Staren:
Oh I didn't know that !

I did not know either, till I just checked.

So I checked the .h file and found this:
GND----------GND
3V3----------3.3V
interrupt 0 pin D2-----------DIO0
SS pin D10----------NSS
SCK pin D13----------SCK
MOSI pin D11----------MOSI
MISO pin D12----------MISO

After putting all the cables I tried to start the program but it said "Init failed "

At the Init function, there are a few things that could return false, but this one could be the one because it prints "0" before "init failed ":

Serial.println(spiRead(RH_RF95_REG_01_OP_MODE), HEX);
return false; // No device present?

In that case, I don't know why they would say there is no device present

Do you know what it could be ?

Staren:
Do you know what it could be ?

Well the code works, so presumably you either wired it wrong or your RFM95 or Arduino are faulty.

I'm gonna check the wires then.
Do you want to check with me ?
I can send some pictures of my board and my fm95

Your welcome to post pictures, but they dont always tell the full story.

What Arduino are you using ?


There's the picture
Everything seems okay for me

I'm on an Arduino Uno

Staren:
There's the picture
I'm on an Arduino Uno

What picture ?

What logic level converters are you using ?

Dangit, the website seems not to be accepted

Here, another link from another website

Edit: doesn't work

Posting the link instead of the pic then, don't blame me moderators

You MUST have logic level converters between a 5V Arduino and the 3.3V radio.

Staren:
Imgur: The magic of the Internet

No logic level converters.

Bye bye RFM95.

What do you mean ?

I don't even know what's a logic converter
So basically I just broke my chip ?

Staren:
What do you mean ?

I don't even know what's a logic converter
So basically I just broke my chip ?

The UNO I\O (logic) pins are 5V output, the RFM95 is a 3.3V device, there is a note about it in the RH_RF95.h library file and of course its in the RFM95 datasheet.

Sometimes a 3.3V device will survive having 5V applied to its 3.3V pins, sometimes not.

Try a Google search on 'logic level converters'

So basically I just broke my chip ?

No big deal. We've all done that, even when we knew better.

Chalk it up to learning the hobby!

Okay so I ordered a logic level converter and it might be there in two days
Let's hope I didn't break the chip, I mean I still have another but alone it won't do much
Thanks a lot for your help, I might be able to do something on my IT stage !

One of the issues to be aware of with logic level converters is that the el-cheapo ones you will find on eBay can be marginal with relativly high speed (4Mhz +) SPI buses.

They do seem to work but the signals dont look too good on a scope.

A far better 'solution' is to get a 3.3V Pro Mini.