政府网站开发/seo多久可以学会
上面的DIO maping 看懂就比较好理解了，DIO0,DIO1,DIO3,
发送和接收都可以触发中断，cad模式需要使用CADDetected和CADDone。
CADDetected这个中断就是有数据接收了，触发进入接收模式，前导码个数的计算还是比较简单的。
从上图可以看出，若要可靠唤醒 WOR，发送包的前导码必须大于 T1+2*T2 才能可靠唤醒。
TS=2^SF/BW 这个值是一个字节传输所用的时间，发送前导码的个数对应的的时间要不小于T1+2*T2才能唤醒。
举个例子：SF=9,BW=125K,传输一个码元的时间就是TS=2^SF/BW=2^9/125K=4.1ms/symb，
睡眠时间加上CAD时间除以单个码元的时间就是合理的前导码长度，这个长度在一个周期内足以唤醒模块。就是发包的时间有点久。
lora_write(0x20,0x03)--前导码长度
lora_write(0x21,0xec)--前导码长度
lora_write(0x21,0xec)--前导码长度
目前使用2017年在stm32平台开发的lora dtu,现在移植到lua 的平台。
想要实现实时通信，可以借助运营商基站工作原理（通信原理），蜂窝通信，一回事，使用一组公共信道（收发上行和下行，注册使用），然后从机使用公共信道注册，rssi符合要求，分配一组上行和下行信道给其使用。
local lora = {}
local sys = require "sys"local spiId = 2
local _nss=13
local _dio0=8
local _dio1=4
local _dio3=5
local MC1={BW125=0x70,BW250=0x80,BW500=0x90,BW150=0x00
}local MC2={FSK=0x00,SF6=0x60,SF7=0x70,SF8=0x80,SF9=0x90,SF10=0xA0,SF11=0xB0,SF12=0xC0
}-- MC1["4/5"]=0x02
-- MC1["4/6"]=0x04
-- MC1["4/7"]=0x06
-- MC1["4/8"]=0x08
local _freq=470000000
local _bw=MC1.BW125
local _sf=MC2.SF9local cspin = gpio.setup(_nss, 1)
local rst = gpio.setup(9, 1)--收发数据
local function sendRecv(data,len)local r = ""cspin(0)if data then spi.send(spiId,data) endif len then r = spi.recv(spiId,len) endcspin(1)return r
endlocal function lora_read(addr)return string.byte(sendRecv(string.char(addr),1))
endlocal function lora_write(addr,value)cspin(0)spi.send(spiId,string.char(addr+0x80,value))cspin(1)
end
local function setFreq(freqHz)-- local FRF_MSB=0x06-- local FRF_MID=0x07-- local FRF_LSB=0x08local frfMsb,frfMid,frfLsb=0x75,0x80,0x00local frf=(freqHz/1000*2^11)/125frfMsb = (frf>>16)%256 frfMid = (frf>>8)%256frfLsb = (frf>>0)%256lora_write(0x06,frfMsb)lora_write(0x07,frfMid)lora_write(0x08,frfLsb)print(string.format("%0d hz %02X %02X %02X ",freqHz,frfMsb,frfMid,frfLsb))endlocal function setRate(sf,bw,cr,crc,iiq,powe)-- local SF10=0xA0-- local SF11=0xB0-- local SF12=0xC0-- local PA_CONFIG=0x09-- local MODEM_CONFIG1=0x1D-- local MODEM_CONFIG2=0x1E-- local MODEM_CONFIG3=0x26-- local SYMB_TIMEOUT_LSB=0x1F-- local INVERT_IQ=0x33local mc1=bit.bor(bw,cr)local mc2=bit.bor(sf,crc)--local mc3=0x04local mc3=0x00 -- no AGCif (sf == 0xB0 or sf == 0xC0) then mc3=0x08 end -- MC2.SF11=0xB0, MC2.SF12=0xC0local stl=0x08if (sf == 0xA0 or sf == 0xB0 or sf == 0xC0) then stl=0x05 endlocal pac if powe > 17 then pac = 0x8F -- 17dbmelseif powe < -3 then pac = 0x20 -- -3dbmelseif powe <= 12 then pac = 0x20+powe+3 -- -3dbm .. 12dbmelse pac = 0x80+powe-2 -- 13dbm .. 16dbm endlora_write(0x09,pac)--发射功率lora_write(0x1D,mc1)lora_write(0x1E,mc2)lora_write(0x26,mc3)lora_write(0x1F,stl)lora_write(0x33,iiq)
endlocal function setChannel(freq,sf)-- local HOP_PERIOD=0x24-- local FIFO_ADDR_PTR=0x0D-- local FIFO_RX_BASE_AD=0x0F-- local CR4_5=0x02-- local CRC_ON=0x04setFreq(freq)setRate(sf,_bw,0x02,0x04,0x27,14) -- CR4/5=0x02, CRC_ON=0x04lora_write(0x24,0x00)lora_write(0x0D,lora_read(0x0F))
end--射频接收数据
local function RcvData()local count = lora_read(0x13)--获取数据长度lora_write(0x0D,lora_read(0x10))--指针需要手动清零return sendRecv(string.char(0x00),count)--读数据
end--DIO0--RxDone------------------------------------------------------
local getCount=0
local function dio0handler()lora_write(0x12,0xff)--清除全部的中断标志位if lora_read(0x40) == 0x40 thenprint("TxDone")if station_Module=="main" then --主站Rx_mode("lora") end elseprint("RxDone")local data_buff=RcvData()local pkt_rssi=lora_read(0x1A)local rssi=lora_read(0x1B)pkt_rssi=-137+16/15*pkt_rssigetCount=getCount+1local buff=string.format("rssi:%d,pkt_rssi:%f,getCount:%d.",rssi,pkt_rssi,getCount)print(data_buff,#data_buff,buff)if station_Module=="main" then --主站--RFSend(buff,"wor") elseRFSend(buff,"lora")end endend
--DIO1--CADDetected------------------------------------------------------
local function dio1handler()Rx_mode("wor")print("CADDetected")lora_write(0x12,0xff)--清除全部的中断标志位sys.timerStart(RF_Sleepmode,4000)
end
--DIO3---CADDone------------------------------------------------------
local function dio3handler()print("CADDone")lora_write(0x12,0xff)--清除全部的中断标志位RF_Sleepmode()end--接收模式
function Rx_mode(flag)--local REG_LR_OPMODE = 0x01
--local REG_LR_PREAMBLEMSB = 0x20
--local REG_LR_PREAMBLELSB = 0x21
--local REG_LR_PAYLOADLENGTH = 0x22
--local RFLR_OPMODE_STANDBY = 0x01
--local REG_LR_DIOMAPPING1 = 0x40
--local RFLR_DIOMAPPING1_DIO0_00= 0x00
--local REG_LR_FIFOADDRPTR = 0x0D
--local RFLR_OPMODE_RECEIVER = 0x05
--local REG_LR_IRQFLAGS = 0x12--gpio.close(_dio0)gpio.close(_dio1)gpio.close(_dio3)setConfig(cid,"rxd")lora_write(0x01,0x81) -- set mode LoRa standbyif flag=="wor" then lora_write(0x20,0x03)--前导码长度lora_write(0x21,0xec)--前导码长度elseif flag=="lora" thenlora_write(0x20,0)--前导码长度lora_write(0x21,10)--前导码长度end lora_write(0x40,0x00)-- 把DIO0-RXDONE标志位写入中断映射寄存器 lora_write(0x12,0xff)-- clear interrupt flags gpio.setup(_dio0,dio0handler,gpio.PULLDOWN,gpio.RISING) lora_write(0x0D,lora_read(0x0E))lora_write(0x01, 0x85)--set mode LoRa rxContinuous end
--发送数据
function RFSend(SendBuf,flag)
--local REG_LR_OPMODE = 0x01
--local REG_LR_PREAMBLEMSB = 0x20
--local REG_LR_PREAMBLELSB = 0x21
--local REG_LR_PAYLOADLENGTH = 0x22
--local REG_LR_FIFOADDRPTR = 0x0D
--local REG_LR_IRQFLAGS = 0x12
--local REG_LR_IRQFLAGSMASK = 0x11
--local REG_LR_DIOMAPPING1 = 0x40
--local RFLR_IRQFLAGS_TXDONE = 0x08setConfig(cid,"txd")gpio.close(_dio0)gpio.close(_dio1)gpio.close(_dio3)lora_write(0x01,0x81) if flag=="wor" then lora_write(0x20,0x03)--前导码长度lora_write(0x21,0xec)--前导码长度elseif flag=="lora" thenlora_write(0x20,0)--前导码长度lora_write(0x21,10)--前导码长度end lora_write(0x40,0x40)--RFLR_DIOMAPPING1_DIO0_01lora_write(0x12,0xff) --clear interrupt flagsgpio.setup(_dio0,dio0handler,gpio.PULLDOWN,gpio.RISING)lora_write(0x0D,lora_read(0x0E)) lora_write(0x22,#SendBuf) --发送数据的长度sendRecv(string.char(0x00+0x80)..SendBuf)lora_write(0x01,0x83)--sendprint("RFSend",SendBuf)endfunction RF_Sleepmode()lora_write(0x01,0x81) lora_write(0x12,0xff) lora_write(0x01,0x80)--sleep gpio.close(_dio0)gpio.close(_dio1)gpio.close(_dio3)print("RF_Sleepmode")--esp32.enterLightSleep(esp32.RTC, 4 * 1000 * 1000)--RF_CAD_Sample()sys.timerStart(RF_CAD_Sample ,4000)
end
-- 说明: DIO1--CADDetected DIO3---CADDone
-- 说明 : 采样时间约为(2^SF+32)/BW
function RF_CAD_Sample()
--local RFLR_DIOMAPPING1_DIO3_00 = 0x00
--local RFLR_DIOMAPPING1_DIO1_10 = 0x20 gpio.close(_dio0)gpio.setup(_dio1,dio1handler,gpio.PULLDOWN,gpio.RISING)gpio.setup(_dio3,dio3handler,gpio.PULLDOWN,gpio.RISING)setConfig(cid,"rxd")lora_write(0x01,0x81)lora_write(0x20,0x1f)--设置前导码长度为最长lora_write(0x21,0x48)lora_write(0x40,0x20)--dio3:CadDone.dio1:CadDetected RFLR_DIOMAPPING1_DIO3_00 | RFLR_DIOMAPPING1_DIO1_10 lora_write(0x01,0x87)--cad lora_write(0x12,0xff)--clear interrupt flagsprint("RF_CAD_Sample")end
station_Module="main1"
cid = 99991234
function setConfig(cid,rxtx)local RFoffset=(cid % 250)* 200000local RF=420000000if rxtx=="rxd" then--接收if station_Module=="main" then --主站RF=420000000 + RFoffsetelseRF=470000000 + RFoffsetendelse --发送if station_Module=="main" thenRF=470000000 + RFoffsetelseRF=420000000 + RFoffsetendendsetChannel(RF,MC2.SF9)
end
function lora.sxInit()rst(0)local result = spi.setup(spiId, _nss,0,0,8,10000)print("open",result)if result ~= 0 then--返回值为0，表示打开成功print("spi open error",result)endrst(1)if lora_read(0x42) == 0x12 and lora_read(0x44)==0x2D thenprint("start init")else print("Unknown radio")--returnend
--local REG_LR_MODEMCONFIG3 = 0x26
--local REG_LR_MODEMCONFIG1 = 0x1D
--local REG_LR_MODEMCONFIG2 = 0x1E
--local REG_LR_PREAMBLELSB = 0x21
--local REG_LR_PARAMP = 0x0Alora_write(0x01,0x00)--设置为SLEEP模式 lora_write(0x01,0x80)--并且设置为LORA模式lora_write(0x01,0x81)--设置为STANDBY模式lora_write(0x4D,0x07)--最大发射功率20dmb开启lora_write(0x0A,0x02)-- 上升，下降的斜率设置为1000US lora_write(0x0B,bit.bor(0x20,0x1B))--过流保护开启，最大承载电流为240MA if station_Module == "main" then --主节点sys.timerLoopStart(RFSend,8000,"HELLO WORLD 0000000000000 12355555555558844442222111","wor")print("lora init 主节点 ok")else --低功耗从机--setChannel(_freq,MC2.SF9)sys.timerStart(RF_Sleepmode,500)print("lora init 从机 ok")endendreturn lora以上代码可以直接使用，
下面是接线图
