新手求教：如何用lua解析json电报

GET http://192.168.1.122:8080/devices/019D202A/telegrams 得到的电报

{
  "header" : {
    "httpStatus" : 200,
    "content" : "telegrams",
    "gateway" : "DC-GW/EO-IP v0.99.6",
    "timestamp" : "1970-01-01T08:07:46.898+0800"
  },
  "telegrams" : [ {
    "deviceId" : "019D202A",
    "friendlyId" : "hhh666",
    "physicalDevice" : "99999",
    "timestamp" : "1970-01-01T08:05:14.072+0800",
    "direction" : "from",
    "functions" : [ {
      "key" : "supplyVoltage",
      "value" : 3.60,
      "unit" : "V"
    },{
    "deviceId" : "019D202A",
    "friendlyId" : "hhh666",
    "physicalDevice" : "99999",
    "timestamp" : "1970-01-01T08:06:24.098+0800",
    "direction" : "from",
    "functions" : [ {
      "key" : "supplyVoltage",
      "value" : 3.66,
      "unit" : "V"
    }, {
      "key" : "illumination",
      "value" : 244.00,
      "unit" : "lx"
    }, {
      "key" : "temperature",
      "value" : 21.20,
      "unit" : "°C"
    }, {
      "key" : "motionDetected",
      "value" : "true",
      "meaning" : "PIR on"
    }, {
      "key" : "occupancyButton",
      "value" : "pressed",
      "meaning" : "Button pressed"
    } ],
    "telegramInfo" : {
      "data" : "B77A6A08",
      "status" : "0",
      "dbm" : -61,
      "rorg" : "A5"
    }
  } ]
}

如何用lua脚本解析一个值输出；如上面代码中有“supplyVoltage”“illumination”“temperature”“motionDetected”“occupancyButton”等值，只取一个值
解析格式类似与

function parameter (value) 
return "/temperature/setTemp.php?temp="..value end 

这种格式

啊啊~~~~~！

可以参考我的这篇文章：https://blog.csdn.net/qq_42450988/article/details/115037925