[Tutorial] Raspberry Pi NRF24l01 direct connection

Vladut Grecu

[EDIT] - I uploaded a script in the next post that does everything I explained below

I have installed MINImal raspBIAN which is a raspBIAN without a gui. So this should work for you guys.

First of all you have to
1. Undo your Overclock. If you have any. (SPI does not like Overclocked pi's)

2. Enable SPI

Details:

On a normal raspbian image this can be done either on a fresh install (when you config your pi) or you can type in terminal sudo raspi-config
From there you go into ADVANCED OPTIONS -> SPI

On a minimal image you don't have the luxury of raspi-config. You have to manually activate it.
(I already had it enabled but you can check)
(If you don't have sudo installed on your image just run apt-get install sudo)

sudo nano /etc/modprobe.d/raspi-blacklist.conf

Make sure there IS a # before blacklist spi-bcm2708, so it looks like this…
#blacklist spi-bcm2708

If there is no line like that, you can add it. It won't do any harm.
CTRL+O - Save
ENTER - Confirm
CTRL+X - Exit

or

CTRL+X - Exit
y - I want to save the file
ENTER - Confirm

We have to edit now the config.txt.
sudo nano /boot/config.txt

add this to the end of the line
dtparam=spi=on

Save and exit.

Reboot your pi.
sudo reboot

Enjoy using SPI. (Source)

3.Downloading the files

Details:

You have 2 options. wget and git-clone. I'll start with:

a. git-clone

If you don't have git-clone you need to install the git tools. (Yes, git is related to github)
sudo apt-get install git

After you installed git you simply navigate to the folder that you wish to install the program and type:
sudo git-clone https://github.com/mysensors/Raspberry.git

This will download a zip, unarchive it and.. It does all the jobs for you.

b. wget

Some ppl are old-school and go the hard way or they just enjoy it done this way.

Navigate to the folder that you wish to install the program and type:
wget https://github.com/mysensors/Raspberry/archive/master.zip (this will download you the zip)

Unzip the file

If you don't have unzip installed just type
sudo apt-get install unzip

unzip master.zip -d /home/pi/Raspberry (you can specify any directory that you want instead of the /home/pi/Raspberry)

4.Edit and compile what you downloaded

In the Raspberry folder you have some files and some folders.
The majority of ppl (including me) forget to complile the libs for the NRF24l01.
This is the library provided by [TMRH20]{http://tmrh20.github.io} (He has some interesting stuff there including an audio library for NRF24l01.)
Back to our stuff.
Go to the Raspberry folder then into librf24-bcm.
cd Raspberry/librf24-bcm/

Type
make

Go back to the Raspberry folder
cd ..

Type
make
5.Connecting the NRF

Mister TMRH20 tells us that we need to connect the NRF24l01 this way

PIN		NRF24L01	RPI				RPi -P1 Connector
1		GND			rpi-gnd			(25)
2		VCC			rpi-3v3			(17)
3		CE			rpi-gpio22		(15)
4		CSN			rpi-gpio8		(24)
5		SCK			rpi-sckl		(23)
6		MOSI		rpi-mosi		(19)
7		MISO		rpi-miso		(21)
8		IRQ			Not Connected

Connect everything like that except for the CE pin

Run the PiGatewaySerial
./PiGatewaySerial

It shoud prin something like this:

Starting PiGatewaySerial...
Protocol version - 1.4
Created PTY '/dev/pts/1'
Gateway tty: /dev/ttyMySensorsGateway
================ SPI Configuration ================
CSN Pin          = CE0 (PI Hardware Driven)
CE Pin           = Custom GPIO25
Clock Speed      = 8 Mhz
================ NRF Configuration ================
STATUS           = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0
RX_ADDR_P0-1     = 0xe7e7e7e7e7 0xc2c2c2c2c2
RX_ADDR_P2-5     = 0xff 0xc4 0xc5 0xc6
TX_ADDR          = 0xe7e7e7e7e7
RX_PW_P0-6       = 0x00 0x00 0x20 0x00 0x00 0x00
EN_AA            = 0x3b
EN_RXADDR        = 0x07
RF_CH            = 0x10
RF_SETUP         = 0x23
CONFIG           = 0x0e
DYNPD/FEATURE    = 0x3f 0x06
Data Rate        = 250KBPS
Model            = nRF24L01+
CRC Length       = 16 bits
PA Power         = PA_LOW

Look at line 7 CE Pin = Custom GPIO25
Connect the CE pin where it says you should.

Here are some pictures with the GPIO connector on the rPi.
https://www.google.ro/search?q=raspberry+pi+gpio&tbm=isch

Vladut Grecu

Here is a script I made that does all the things above
RasNRF-GPIO.sh
Tell me how it went. Did it helped you? Did you found a bug? Any input, bad or good is appreciated.

blksun813

@Vladut-Grecu

The instructions didn't work for me until I did a sudo make install in the librf24-bcm folder. After the libraries were installed, I was able to make the PiGateway and PiGatewaySerial executables.
Also, PiGatewaySerial will only run as root (or sudo).

Thanks for the instructions, it was a great starting point! Now to install a controller....

n3ro

Hey folks,

big THX for the tut.

But i have some problems after starting the GW.

My output is only:

./PiGatewaySerial
Starting PiGatewaySerial...
Protocol version - 1.4
Created PTY '/dev/pts/1'
Gateway tty: /dev/ttyMySensorsGateway
check wires

and a 100% CPU Load.

regards,
n3ro

issue in GIT:
https://github.com/mysensors/Raspberry/issues/11

n3ro

No ideas?

Sander Teunissen

the ttyMysensorsGateway can only be accessed as root (user root, group root).
Other serialports seem to have the group "dialout" attached.

I am running node-red which is unable the gateway and I guess this has to do with it. Anyone a solution ?

Andreas Maurer

? Are you using the code that is available on github now?

This behavior was Change by Holger a month ago. You can configure the Groups in the makefile:

The standard configuration will build the Serial Gateway with a tty name of
'/dev/ttyMySensorsGateway' and PTS group ownership of 'tty' the PTS will be group read
and write. The default install location will be /usr/local/sbin. If you want to change
that edit the variables in the head of the Makefile.

Sander Teunissen

@Andreas-Maurer Thanks for the quick answer. I used the code from github. I am going to check your suggestions tonight. (right now I am at work ;-)

Sander.

Roberto Brunialti

Sorry for my naive question: does it means I ca use a raspi as a nrd24l01 based gateway?

Sander Teunissen

@Roberto-Brunialti Yes. Works perfectly ! (apart from the root access ;-)
As stated by blksun813 you need to "sudo make install in the librf24-bcm folder". (add the sudo...)

andriej

I'm currently at work, but there's a question: will it run on orangepi? (bananapi-like clone of RPi)
I'll take a look at the code and try to manage... GPIOs are working almost the same (it's compatible).

Maybe if I make a diff-file of things changed, you will be able to merge it and do some 'ifs' so code will be clone-compatible?

Oh well... The library has -bcm in name so I guess it will be rather hard to get it to work...

Sander Teunissen

@Andreas-Maurer

to run the gateway:
sudo ./PiGatewaySerial (without sudo I get the error below)

Could not create a symlink '/dev/ttyMySensorsGateway' to PTY! (13) Permission denied

running:
ls -l ttyMySensorsGateway

gives the following:

lrwxrwxrwx 1 root root 10 May  7 17:27 ttyMySensorsGateway -> /dev/pts/2

I checked the makefile and it says

TTY_GROUPNAME := tty

But it doesn't seem to do anything...Any ideas ?

Andreas Maurer

The symlink alwayshas 777. Everyone can use it.
Please have a look at /dev/pts/2 This device should have the configured groups.

Ok?

Sander Teunissen

@Andreas-Maurer said:

The symlink alwayshas 777. Everyone can use it.
Please have a look at /dev/pts/2 This device should have the configured groups.

Ok?

Yes. Ok!
It works.
Thanks !

Sweebee

I tested it on my Rpi B+ its working fine, but the cpu load is always 100%. Is this normal?

Roberto Brunialti

An other silly question: can I install a controller into the same raspberry pi (the one with this gateway and nrf )? Are all controllers suitable for such a configuration ?
Thanks!

Andreas Maurer

For my Point of view, every Controller which is able to use the Serial Gateway.

joaoabs

@Sweebee

Same here. I'm afraid that with the PI at 100% there is no much use of this code becasue we can't do anything else...

Strange that the PI that is much powerfull than an arduino gets so high CPU for something that an arduino nano can do...

Could it be something that could be improved?

Cheers,
Joaoabs

Andreas Maurer

I have no problem with it. fhem as controler and mysql as DB is running on the same PI.
The Gateway is not even listed in "top"

joaoabs

@Andreas-Maurer

Do you mean you don't have any problems with the fact the CPU is at 100% or you simply don't have the same sympthom?

Thanks for replying,
Joaoabs

[Tutorial] Raspberry Pi NRF24l01 direct connection

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