PANIC: unprotected error in call to Lua API (script1.lua:34: attempt to index global 'http' (a nil value))

Question

I get this error when trying to perform a HTTP GET request on my NodeMCU (using Lua programming language). It is connected via WiFi.

When the PIR sensor (Passive IR sensor) detects movement, the function roepIFTTT() gets called. The HTTP POST to IFTTT works well.

PANIC: unprotected error in call to Lua API (script1.lua:35: attempt to index global 'http' (a nil value))

 ets Jan  8 2013,rst cause:2, boot mode:(3,7)

load 0x40100000, len 26096, room 16 
tail 0
chksum 0x0c
load 0x3ffe8000, len 2232, room 8 
tail 0
chksum 0x7a
load 0x3ffe88b8, len 8, room 8 
tail 0
chksum 0x5f
csum 0x5f
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That's the firmware:

NodeMCU custom build by frightanic.com
    branch: master
    commit: 7b83bbb2ea134cd85ac9d63108603cc02c4e20f7
    SSL: false
    modules: adc,bit,cjson,coap,dht,file,gpio,i2c,mqtt,net,node,ow,pwm,rtctime,sntp,spi,tmr,uart,wifi,ws2812
 build  built on: 2016-11-25 08:30
 powered by Lua 5.1.4 on SDK 1.5.4.1(39cb9a32)

---

Here is my code:

wifi.setmode(wifi.STATION)
wifi.sta.config("ssid", "password")
wifi.sta.connect()

ledpen = 0
gpio.mode(ledpen, gpio.OUTPUT)
gpio.write(ledpen, gpio.HIGH)

pirsensorpen = 2

gpio.mode(pirsensorpen, gpio.INT, gpio.PULLUP)

function beweging() -- This function gets called when movement is detected
    print("PIR sensor detecteerde beweging")
    gpio.write(ledpen, gpio.LOW)
    roepIFTTT(1)
    tmr.alarm(0, 2000, tmr.ALARM_SINGLE, function()
        gpio.write(ledpen, gpio.HIGH)
    end)
end

function roepIFTTT(value1)
  -- Trigger flashbutton op IFTTT
  conn = nil
  conn = net.createConnection(net.TCP, 0)
  conn:on("receive", function(conn, payload) end)
  conn:connect(80,"maker.ifttt.com")
  conn:on("connection", function(conn, payload)
  conn:send("POST /trigger/pirsensor/with/key/API_KEY?value1="..value1.." HTTP/1.1\r\nHost: maker.ifttt.com\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n") end)
  conn:close()
  print("IFTTT is aangeroepen")



-- It is about the code below that generates the error. If there is another way if creating a simple HTTP GET request, it is welcome.
    http.get("http://httpbin.org/ip", nil, function(code, data)
    if (code < 0) then
      print("HTTP request failed")
    else
      print(code, data)
    end
  end)
  -- coe above


end

function metingNaarThingSpeak()  
  local a = adc.read(0)
  print("Value of moisture sensor: "..a)
  local conn = nil
  conn = net.createConnection(net.TCP, 0)
  conn:on("receive", function(conn, payload) end)
  conn:connect(80, "api.thingspeak.com")
  conn:on("connection", function(conn, payload)
  conn:send("GET /update?api_key=API_KEY&field1="..a.." HTTP/1.1\r\nHost: api.thingspeak.com\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n") end)
  conn:close()
  print("Meting naar ThingSpeak verzonden")
end

gpio.trig(pirsensorpen, "up", beweging)
tmr.alarm(4, 60000, tmr.ALARM_AUTO, function() metingNaarThingSpeak() end)

What am I doing wrong?

Note: I am a complete newbie at this and I have never programmed in Lua, nor have I worked with a NodeMCU. I have other programming skills, so programming is no new thing to me.

Answer 1

The error is right here

modules: adc,bit,cjson,coap,dht,file,gpio,i2c,mqtt,net,node,ow,pwm,rtctime,sntp,spi,tmr,uart,wifi,ws2812

Your NodeMCU firmware is missing the HTTP module.