最近买了几个NRF24L01模块用来做无线通讯,而我手中正好有两个树莓派和一个beaglebone balck,就打算使用nrf24l01来做这三个设备的通讯.可以玩的花样很多,NRF24L01基于SPI接口,普通的单片机就可以使用,所以可以很简单的实现arduino和树莓派等的无线通讯.NRF24L01是基于Zigbee通讯协议的.这里以一台树莓派为主机,一台树莓派为从机,一台beaglebone为从机,实现三台机器的组网通讯.
一 树莓派和beaglebone black和NRF24L01的连线
NRF24l01是基于SPI接口的:
与树莓派的连线:
NRF24L01 => 树莓派
GND => GND
VCC => 3.3V
CE => GPIO25 即22管脚
CSN => CE0(GPIO8) 即 24管脚
SCK => SCLK(GPIO11)即23管脚
MOSI => MOSI(GPIO10)即19管脚
MISO => MISO(GPIO9)即21管脚
IRQ => GPIO18即12管脚
两个树莓派和NRF24L01的连线是一样的
Beaglebone black与NRF24L01的连线:
NRF24L01 => beaglebone black
GND => GND
VCC => 3.3V
CE => GPIO_48 (P9_15)
CSN => SPI0_CS0(P9_17)
SCK => SPI0_SCLK(P9_22)
MOSI => SPI0_D1(P9_18)
MISO => SPI0_D0(P9_21)
IRQ => GPIO_51(P9_16)
二 树莓派安装NRF24L01的python库
需要先安装树莓派上的gpio python库,没有装的,可以先看我这篇博客:
树莓派raspberry使用python实现GPIO输入输出-按键LED
NRF24L01 这里参考 Learn from fly上的文章:
git clone https://github.com/riyas-org/nrf24pihub
cd nrf24pihub
cd python-spi
sudo python setup.py install
cd ../
还需要打开树莓派上的SPI口:
vi /etc/modprobe.d/raspi-blacklist.conf
#blacklist spi-bcm2708 ＃使用井号注释掉这行
blacklist i2c-bcm2708 #如果要使用i2c就注释掉这行
重启.会在/dev里面多出两个文件:spidev0.0,spidev0.1
三 Beaglebone Black安装NRF24L01的python库
需要先安装Adafruit_GPIO库:
git clone git://github.com/adafruit/adafruit-beaglebone-io-python.git
/usr/bin/ntpdate -b -s -u pool.ntp.org
opkg update && opkg install python-distutils
cd adafruit-beaglebone-io-python
python setup.py install
安装NRF24L01库,使用pynrf24:
git clone https://github.com/jpbarraca/pynrf24
cd pynrf24
python setup.py install
打开SPI支持:
用文本编辑器打开uEnv.txt
在里面最后一行加入下面的语句：optargs=capemgr.enable_partno=BB-SPIDEV0
重启.会在/dev里面多出两个文件:spidev1.0,spidev1.1
四 树莓派主机程序:
master_receive.py:
from nrf24 import NRF24
import time
from time import gmtime, strftime
#设定从机的发送地址pipes[0],pipes[1],本机的发送pipes[0]
pipes = [[0x10, 0x10, 0x10, 0x10, 0x20], [0x10, 0x10, 0x10, 0x10, 0x22]]
radio = NRF24()
radio.begin(0, 0,25,18) #set gpio 25 as CE pin,gpio 18 as IRQ pin
radio.setRetries(15,15)
radio.setPayloadSize(32)
radio.setChannel(0x4c)
radio.setDataRate(NRF24.BR_250KBPS)
radio.setPALevel(NRF24.PA_MAX)
radio.setAutoAck(1)
radio.openWritingPipe(pipes[0])
radio.openReadingPipe(1, pipes[1])
radio.startListening()
radio.stopListening()
radio.printDetails()
radio.startListening()
while True:
pipe = [0] #pipe为接收到的信息的从机从机身份标识
while not radio.available(pipe, True):
time.sleep(100/1000000.0)
recv_buffer = []
radio.read(recv_buffer)
out = ''.join(chr(i) for i in recv_buffer)
print "Message from "+str(pipe[0])+":"+out
五 树莓派从机程序
raspberry_send.py
from nrf24 import NRF24
import time
from time import gmtime, strftime
pipes = [[0x10, 0x10, 0x10, 0x10, 0x20], [0x10, 0x10, 0x10, 0x10, 0x12]]
radio = NRF24()
radio.begin(0, 0,25,18) #set gpio 25 as CE pin
radio.setRetries(15,15)
radio.setPayloadSize(32)
radio.setChannel(0x4c)
radio.setDataRate(NRF24.BR_250KBPS)
radio.setPALevel(NRF24.PA_MAX)
radio.setAutoAck(1)
radio.openWritingPipe(pipes[0])
radio.openReadingPipe(1, pipes[1])
radio.startListening()
radio.stopListening()
radio.printDetails()
radio.startListening()
count = 1
while True:
pipe = [0]
send_data = "send count: "+str(count)
print "start send data..."
print "send data:"+str(count)
radio.stopListening()
ok = 0
ok_true = 32
while ok!=ok_true:
ok = radio.write(send_data)
time.sleep(2)
count = count + 1
六 beaglebone black 从机发送程序
beaglebone_send.py:
from nrf24 import NRF24
import time
pipes = [[0x10, 0x10, 0x10, 0x10, 0x22], [0x10, 0x10, 0x10, 0x10, 0x11]]
radio = NRF24()
radio.begin(1, 0, "P9_15", "P9_16") #Set CE and IRQ pins
radio.setRetries(15,15)
radio.setPayloadSize(32)
radio.setChannel(0x4c)
radio.setDataRate(NRF24.BR_250KBPS)
radio.setPALevel(NRF24.PA_MAX)
radio.openWritingPipe(pipes[0])
radio.openReadingPipe(1, pipes[1])
radio.startListening()
radio.stopListening()
radio.printDetails()
buf = ['P', 'I', 'N', 'G']
count = 1
while True:
send_data = "send:"+str(count)
print send_data
ok_true = 32
while ok!=ok_true:
ok=radio.write(send_data)
print ok
time.sleep(2)
count = count+1
七 启动程序测试
树莓派主机: sudo python master_receive.py
树莓派从机:sudo python raspberry_send.py
beaglebone从机:sudo python beaglebone_send.py
收到的数据:
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