script/libs/pca9685.lua

   1 --[[
   2 @module pca9685
   3 @summary pca9685 16路PWM驱动舵机
   4 @version 1.0
   5 @date    2023.12.26
   6 @author  xwtx
   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 PROJECT = "pca9685"
  11 VERSION = "1.0.0"
  12
  13
  14 sys = require("sys")
  15 pca9685=require("pca9685")
  16
  17 local i2c_id = 1
  18 sys.taskInit(
  19     function()
  20         i2c.setup(i2c_id,i2c.SLOW)
  21         sys.wait(1000)
  22         pca9685.init(i2c_id,60)
  23         sys.wait(1000)
  24         local i=0
  25         while true do
  26             pca9685.setpwm(i2c_id,0,i)
  27             if i >= 100 then
  28                 i=0
  29             end
  30             i=i+10
  31             sys.wait(2000)
  32         end
  33     end
  34 )
  35
  36 sys.run()
  37 ]]
  38
  39
  40
  41
  42
  43 local pca9685={}
  44
  45
  46
  47
  48 local PCA_Addr = 0x40   --pwm通道地址
  49 local PCA_Model =0x00   --工作模式：读1/写0
  50 local LED0_ON_L =0x06
  51 local LED0_ON_H =0x07
  52 local LED0_OFF_L= 0x08
  53 local LED0_OFF_H =0x09
  54 local PCA_Pre = 0xFE
  55
  56 local function pca9685_write(i2cId,addr, data)
  57    local ret
  58    ret=i2c.send(i2cId, PCA_Addr, { addr, data })
  59    sys.wait(15)
  60    if ret then
  61       return true
  62    else
  63       return
  64    end
  65 end
  66
  67 local function pca9685_read(i2cId,addr)
  68    i2c.send(i2cId, PCA_Addr, addr)
  69    sys.wait(5)
  70    local data = i2c.recv(i2cId,0x40, 1)
  71    if #data==0 then
  72       return
  73    else
  74       return data
  75    end
  76 end
  77 --[[
  78 pca9685 初始化
  79 @api pca9685.init(i2cId,hz)
  80 @int i2cid 使用的i2c id, 或者是软件i2c的实例
  81 @int hz pca9685的输出频率
  82 @return 成功返回true 失败返回nil
  83 ]]
  84 function pca9685.init(i2cId,hz)
  85    local ret=0
  86    ret=pca9685_write(i2cId,PCA_Model,0x00)
  87    if not ret then
  88       return
  89    end
  90    ret=pca9685.setfreq(i2cId,hz)
  91    if not ret then
  92       return
  93    end
  94    pca9685.setpwm(i2cId,0,0);
  95         pca9685.setpwm(i2cId,1,0);
  96    pca9685.setpwm(i2cId,2,0);
  97    pca9685.setpwm(i2cId,3,0);
  98    pca9685.setpwm(i2cId,4,0);
  99    pca9685.setpwm(i2cId,5,0);
 100    pca9685.setpwm(i2cId,6,0);
 101    pca9685.setpwm(i2cId,7,0);
 102    pca9685.setpwm(i2cId,8,0);
 103    pca9685.setpwm(i2cId,9,0);
 104    pca9685.setpwm(i2cId,10,0);
 105    pca9685.setpwm(i2cId,11,0);
 106    pca9685.setpwm(i2cId,12,0);
 107    pca9685.setpwm(i2cId,13,0);
 108    pca9685.setpwm(i2cId,14,0);
 109    pca9685.setpwm(i2cId,15,0);
 110    sys.wait(100)
 111    return true
 112 end
 113
 114
 115 --[[
 116 pca9685 设置频率
 117 @api pca9685.setfreq(i2cId,freq)
 118 @int i2cid 使用的i2c id, 或者是软件i2c的实例
 119 @int freq pca9685的输出频率,范围为24HZ~1526HZ
 120 @return 成功返回true 失败返回nil
 121 ]]
 122 function pca9685.setfreq(i2cId,freq) --PCA9685频率设置
 123    local prescale
 124    local oldmode
 125    local newmode
 126    local prescaleval
 127    local ret
 128    prescaleval = 25000000;
 129    prescaleval = prescaleval / 4096
 130    prescaleval = prescaleval / freq
 131    prescaleval = prescaleval - 1
 132    prescale = math.floor(prescaleval + 0.5)
 133    oldmode = string.toHex(pca9685_read(i2cId,PCA_Model))
 134    newmode = (oldmode & 0x7F)|0x10
 135    ret=pca9685_write(i2cId,PCA_Model, newmode)
 136    if not ret then
 137       return
 138    end
 139    ret=pca9685_write(i2cId,PCA_Pre, prescale)
 140    if not ret then
 141       return
 142    end
 143    ret=pca9685_write(i2cId,PCA_Model, oldmode)
 144    if not ret then
 145       return
 146    end
 147    sys.wait(5)
 148    ret=pca9685_write(i2cId,PCA_Model, oldmode|0xa1)
 149    if not ret then
 150       return
 151    end
 152    return true
 153 end
 154
 155 --[[
 156 pca9685 设置PWM占空比
 157 @api pca9685.setpwm(i2cId,num, duty_cycle)
 158 @int i2cid 使用的i2c id, 或者是软件i2c的实例
 159 @int num 通道号
 160 @int duty_cycle 占空比 0~100
 161 @return 成功返回true 失败返回nil
 162 ]]
 163 function pca9685.setpwm(i2cId,num, duty_cycle)
 164    local  on = 0
 165    if duty_cycle==50 then
 166       on=0
 167    else
 168       on=math.floor(4096*((100-duty_cycle)/100))
 169    end
 170    local off=on+math.floor(4096*(duty_cycle/100))
 171    local ret = i2c.send(i2cId, PCA_Addr, { LED0_ON_L + 4 * num, on & 0xFF, on >> 8, off & 0xFF, off >> 8 })
 172    sys.wait(5)
 173    if ret==false then
 174       return
 175    end
 176    return true
 177 end
 178 return pca9685
 179
 180
 181