Hello, I’m trying to wire 2 RFM69 to a single Arduino Mega, can you help me with the connections please? + 2 level shifters.
Why two RFM69 ?
Getting two RFM69 devices to work OK with the standard liberaries may not be so simple.
I need 2 with different frequencies on each arduino mega, 2 transmitters(433Mhz & 900Mhz) and 2 recievers with same frequencies using only 2 arduino mega.
The connections are easy, just use a different SS pin for each module.
Can you be more accurate please? i'm still considered as a beginner in Arduino stuff. Also can i use the library for both RF's? if not what can i use?
Difficult to advise, you have not said what your project is and what your suggesting may not even be possible with a standard library.
The project is pretty simple, i have 2 RFM69HCW operating at 433Mhz and other 2 RFM69HCW operating and 900Mhz, im supposed to design a transmitter reciever system for both frequencies, the transmitter will transmit random data and the receiver will calculate the RSSI of each data recieved.
I dont see why you need two RFM69s on each Arduino to do that.
The Radiohead library supports the RFM69, the library files include notes on how to connect the RFM69.
Really don't know if you can run two instances of RadioHead. Never tried, never seen the need for it.
Connections should be simple indeed as it's SPI. So MOSI, MISO, SCK are shared and for SS/CS you need a separate connection for each. You'll also need separate pins for the interrupt lines, I recall you have to use pins with external interrupt for this, so pins 2 and 3 on the Uno, check the RadioHead documentation.
If you don't understand the above it's time for you to start learning more about the SPI bus.
wvmarle:
Really don't know if you can run two instances of RadioHead. Never tried, never seen the need for it.Connections should be simple indeed as it's SPI. So MOSI, MISO, SCK are shared and for SS/CS you need a separate connection for each. You'll also need separate pins for the interrupt lines, I recall you have to use pins with external interrupt for this, so pins 2 and 3 on the Uno, check the RadioHead documentation.
If you don't understand the above it's time for you to start learning more about the SPI bus.
I understand, but what about the code? can i use the SPI and RFM69 Libraries for both RF's?
Eg. to create an object for 1 radio i use "// Create a library object for our RFM69HCW module:
RFM69 radio;"
so for the 2nd radio maybe it should be something like this "// Create a library object for our RFM69HCW module:
RFM69 radio2;"
Thanks for the detailed connections.
Hamzehh:
Can i use the SPI and RFM69 Libraries for both RF's?
No idea, what happened when you tried it ?
Is there a point to this exersize, what are you actually trying to measure or achive, or is it just a theoretical project task ?
srnet:
No idea, what happened when you tried it ?Is there a point to this exersize, what are you actually trying to measure or achive, or is it just a theoretical project task ?
I still didn't try it, but i will soon.
It's not a theoretical project, i'm supposed to send data from both transmitters (Sensor data) and calculate its RSSI for each frequency, at different heights.
It's main goal is improving UAV's propagation power loss.
U as in Under water? Then you can stop right here. You're not going to get more than a few mm.
UAV == Unmanned Aerial Vehicle.
Hamzehh:
I still didn't try it, but i will soon.
It's not a theoretical project, i'm supposed to send data from both transmitters (Sensor data) and calculate its RSSI for each frequency, at different heights.
It's main goal is improving UAV's propagation power loss.
Perhaps thats the sort of detail to be included in the first post.
If you had I would have suggested that I cannot see how you can much improve 'propogation loss' that a fixed physical quantity at the frequencies concerned.
Propogation loss varies with frequency of course, rising as frequency rises.
Hamzehh:
I can i use the SPI and RFM69 Libraries for both RF's?
I thought the replies you have had on that subject were quite clear;
"and what your suggesting may not even be possible with a standard library {meaning Radiohead}"
"Really don't know if you can run two instances of RadioHead. Never tried, never seen the need for it"
"No idea, what happened when you tried it ?"