script/libs/ak8963.lua

   1 --[[
   2 @module ak8963
   3 @summary ak8963 地磁传感器
   4 @version 1.0
   5 @date    2023.06.07
   6 @author  Dozingfiretruck
   7 @usage
   8 --注意:因使用了sys.wait()所有api需要在协程中使用
   9 -- 用法实例
  10 local ak8963 = require "ak8963"
  11 i2cid = 0
  12 i2c_speed = i2c.FAST
  13 sys.taskInit(function()
  14     i2c.setup(i2cid,i2c_speed)
  15     ak8963.init(i2cid)--初始化,传入i2c_id
  16     while 1 do
  17         sys.wait(100)
  18         local mag = ak8963.get_mag()--获取地磁仪
  19         log.info("ak8963 mag", "mag.x",mag.x,"mag.y",mag.y,"mag.z",mag.z)
  20     end
  21 end)
  22 ]]
  23
  24
  25 local ak8963 = {}
  26 local sys = require "sys"
  27 local i2cid
  28 local i2cslaveaddr
  29 local deviceid
  30
  31 local AK8963_ADDRESS_AD0_LOW     =   0x0C
  32 local AK8963_ADDRESS_AD0_HIGH    =   0x0D
  33
  34 ---器件通讯地址
  35 local AK8963_WHO_AM_I            =   0x48 -- AK8963
  36
  37 ---AK8963所用地址
  38 -- Read-only Reg
  39 local AK8963_RA_WHO_AM_I         =   0x00
  40 local AK8963_REG_INFO            =   0x01
  41 local AK8963_REG_ST1             =   0x02
  42 local AK8963_REG_HXL             =   0x03
  43 local AK8963_REG_HXH             =   0x04
  44 local AK8963_REG_HYL             =   0x05
  45 local AK8963_REG_HYH             =   0x06
  46 local AK8963_REG_HZL             =   0x07
  47 local AK8963_REG_HZH             =   0x08
  48 local AK8963_REG_ST2             =   0x09
  49 -- Write/Read Reg
  50 local AK8963_REG_CNTL1           =   0x0A
  51 local AK8963_REG_CNTL2           =   0x0B
  52 local AK8963_REG_ASTC            =   0x0C
  53 local AK8963_REG_TS1             =   0x0D
  54 local AK8963_REG_TS2             =   0x0E
  55 local AK8963_REG_I2CDIS          =   0x0F
  56 -- Read-only Reg (ROM)
  57 local AK8963_REG_ASAX            =   0x10
  58 local AK8963_REG_ASAY            =   0x11
  59 local AK8963_REG_ASAZ            =   0x12
  60 -- Status
  61 local AK8963_STATUS_DRDY         =   0x01
  62 local AK8963_STATUS_DOR          =   0x02
  63 local AK8963_STATUS_HOFL         =   0x08
  64
  65 local AK8963_ASAX
  66 local AK8963_ASAY
  67 local AK8963_ASAZ
  68
  69 --器件ID检测
  70 local function ak8963_check()
  71     i2c.send(i2cid, AK8963_ADDRESS_AD0_LOW, AK8963_RA_WHO_AM_I)--读器件地址
  72     sys.wait(50)
  73     local revData = i2c.recv(i2cid, AK8963_ADDRESS_AD0_LOW, 1)
  74     if revData:byte() ~= nil then
  75         i2cslaveaddr = AK8963_ADDRESS_AD0_LOW
  76     else
  77         i2c.send(i2cid, AK8963_ADDRESS_AD0_HIGH, AK8963_RA_WHO_AM_I)--读器件地址
  78         sys.wait(50)
  79         local revData = i2c.recv(i2cid, AK8963_ADDRESS_AD0_HIGH, 1)
  80         if revData:byte() ~= nil then
  81             i2cslaveaddr = AK8963_ADDRESS_AD0_HIGH
  82         else
  83             log.info("i2c", "Can't find device")
  84             return false
  85         end
  86     end
  87     i2c.send(i2cid, i2cslaveaddr, AK8963_RA_WHO_AM_I)--读器件地址
  88     sys.wait(50)
  89     local revData = i2c.recv(i2cid, i2cslaveaddr, 1)
  90     log.info("Device i2c address is:", revData:toHex())
  91     if revData:byte() == AK8963_WHO_AM_I then
  92         deviceid = AK8963_WHO_AM_I
  93         log.info("Device i2c id is: AK8963")
  94     else
  95         log.info("i2c", "Can't find device")
  96         return false
  97     end
  98     return true
  99 end
 100
 101 --[[
 102 ak8963初始化
 103 @api ak8963.init(i2c_id)
 104 @number 所在的i2c总线id
 105 @return bool   成功返回true
 106 @usage
 107 ak8963.init(0)
 108 ]]
 109 function ak8963.init(i2c_id)
 110     i2cid = i2c_id
 111     sys.wait(20)
 112     if ak8963_check() then
 113         i2c.send(i2cid, i2cslaveaddr, {AK8963_REG_CNTL1, 0x0F})
 114         i2c.send(i2cid, i2cslaveaddr,AK8963_REG_ASAX)
 115         AK8963_ASAX = i2c.recv(i2cid, i2cslaveaddr, 1):byte()
 116         i2c.send(i2cid, i2cslaveaddr,AK8963_REG_ASAY)
 117         AK8963_ASAY = i2c.recv(i2cid, i2cslaveaddr, 1):byte()
 118         i2c.send(i2cid, i2cslaveaddr,AK8963_REG_ASAZ)
 119         AK8963_ASAZ = i2c.recv(i2cid, i2cslaveaddr, 1):byte()
 120         i2c.send(i2cid, i2cslaveaddr, {AK8963_REG_CNTL1, 0x10})
 121         sys.wait(10)
 122         log.info("ak8963 init_ok")
 123         return true
 124     end
 125     return false
 126 end
 127
 128 --获取地磁计的原始数据
 129 local function ak8963_get_mag_raw()
 130     local mag={x=nil,y=nil,z=nil}
 131     i2c.send(i2cid, i2cslaveaddr,AK8963_REG_HXL)
 132     local x = i2c.recv(i2cid, i2cslaveaddr, 2)
 133     _,mag.x = pack.unpack(x,"<h")
 134     i2c.send(i2cid, i2cslaveaddr,AK8963_REG_HYL)
 135     local y = i2c.recv(i2cid, i2cslaveaddr, 2)
 136     _,mag.y = pack.unpack(y,"<h")
 137     i2c.send(i2cid, i2cslaveaddr,AK8963_REG_HZL)
 138     local z = i2c.recv(i2cid, i2cslaveaddr, 2)
 139     _,mag.z = pack.unpack(z,"<h")
 140     return mag or 0
 141 end
 142
 143
 144 --[[
 145 获取地磁仪的数据
 146 @api ak8963.get_mag()
 147 @return table 地磁仪数据
 148 @usage
 149 local mag = ak8963.get_mag()--获取地磁仪
 150 log.info("ak8963 mag", "mag.x",mag.x,"mag.y",mag.y,"mag.z",mag.z)
 151 ]]
 152 function ak8963.get_mag()
 153     local mag={x=nil,y=nil,z=nil}
 154     i2c.send(i2cid, i2cslaveaddr, {AK8963_REG_CNTL1, 0x11})
 155     sys.wait(10)
 156     local tmp = ak8963_get_mag_raw()
 157     mag.x = tmp.x*((AK8963_ASAX-128)*0.5/128+1)
 158     mag.y = tmp.y*((AK8963_ASAY-128)*0.5/128+1)
 159     mag.z = tmp.z*((AK8963_ASAZ-128)*0.5/128+1)
 160     return mag
 161 end
 162
 163 return ak8963
 164
 165