Lua

Script capability allows custom functionality of controller, is based on Lua.

Script settings are in web interface, when you can enable/disable this feature and browsing print output. In Files web interface, you can edit Lua sources. At startup file /data/init.lua will be executed. Lua sources also can be edited through WebDAV, just open in file browser url: dav://<IP>/dav/data/. I recommended this way, because you can use favorite Lua IDE...

In addition to the standard Lua functionality, there is additional modules for controlling charging controller:

• evse
• boardconfig
• aux
• mqtt
• json

evse module

Root level module, for controlling charging controller. Globally loaded, not need require this module.

Constant	Description
evse.STATEA	State A
evse.STATEB1	State B1
evse.STATEB2	State B2
evse.STATEC1	State C1
evse.STATEC2	State C2
evse.STATED1	State D1
evse.STATED2	State D2
evse.STATEE	State E
evse.STATEF	State F
evse.ERRPILOTFAULTBIT	Error pilot_fault
evse.ERRDIODESHORTBIT	Error diode_short
evse.ERRLOCKFAULTBIT	Error lock_fault
evse.ERRUNLOCKFAULTBIT	Error unlock_fault
evse.ERRRCMTRIGGEREDBIT	Error rcm_triggered
evse.ERRRCMSELFTESTFAULTBIT	Error rcm_selftest_fault
evse.ERRTEMPERATUREHIGHBIT	Error temperature_high
evse.ERRTEMPERATUREFAULTBIT	Error temperature_fault

Function	Signature	Description
evse.getstate	():number	Get state, possible values evse.STATE...
evse.geterror	():number	Get error bits, possible values evse.ERR... bits
evse.getenabled	():boolean	Get charging enabled
evse.setenabled	(boolean):nil	Set charging enabled
evse.getavailable	():boolean	Get controller available
evse.setavailable	(boolean):nil	Set controller available
evse.getchargingcurrent	():number	Get charging current in A*10
evse.setchargingcurrent	(number):nil	Set charging current in A*10
evse.getpower	():number	Get charging power in W
evse.getchargingtime	():number	Get charging time in s
evse.getsessiontime	():number	Get session time in s
evse.getconsumption	():number	Get consumption in Wh
evse.getvoltage	():number,number,number	Get voltages in V
evse.getcurrent	():number,number,number	Get current in A
evse.getlowtemperature	():number	Get low temperature
evse.gethightemperature	():number	Get high temperature
evse.adddriver	(table):nil	Add driver

Driver

Driver is table instance which has predefined event methods:

• loop: called every script task loop, approx 50ms
• every100ms: called every 100ms
• every250ms: called every 250ms
• every1s: called every second

Example:

local mydriver = {
  every1s = function()
    evse.setenabled(aux.read("IN1"))
  end
}

evse.adddriver(mydriver)

boardconfig module

This module providing values from board.cfg. Not globally loaded, need require this module.

Constant	Description
boardconfig.ENERGYMETERNONE	Energy meter none
boardconfig.ENERGYMETERCUR	Energy meter current
boardconfig.ENERGYMETERCURVLT	Energy meter current and voltage
boardconfig.SERIALNONE	Serial none
boardconfig.SERIALUART	Serial UART
boardconfig.SERIALRS485	Serial RS485

Value	Description
boardconfig.devicename	Name of the device (string)
boardconfig.proximity	Has PP detection (bool)
boardconfig.socketlock	Has socket lock (bool)
boardconfig.rcm	Has residual current monitor (bool)
boardconfig.energymeter	Energy meter (int), possible values boardconfig.ENERGYMETER...
boardconfig.energymeterthreephases	Is energy meter three phases (bool)
boardconfig.serial1	Type of serial 1 (int), possible values boardconfig.SERIAL...
boardconfig.serial2	Type of serial 2 (int), possible values boardconfig.SERIAL...
boardconfig.serial3	Type of serial 3 (int), possible values boardconfig.SERIAL...
boardconfig.onewire	Has onewire bus (bool)
boardconfig.onewiretempsensor	Has temperature sensor on onewire (bool)
boardconfig.auxin	AUX digital input names (string array)
boardconfig.auxout	AUX digital output names (string array)
boardconfig.auxain	AUX analog input names (string array)

Example:

local boardconfig = require("boardconfig")

print("device name:", boardconfig.devicename)

aux module

This module providing access to AUX. Not globally loaded, need require this module.

Function	Signature	Description
aux.write	(string):boolean	Set digital output value
aux.read	(string):boolean	Get digital input value
aux.analogread	(string):number	Get analog input value

mqtt module

This module providing access to MQTT broker. Not globally loaded, need require this module.

Function	Signature	Description
mqtt.client	(uri: string [, user: string] [, password: string]]):table	Create mqtt client
mqtt.client:setonconnect	(function):nil	Set on connect handler
mqtt.client:setonmessage	(function):nil	Set on message handler
mqtt.client:connect	():nil	Connects to the broker
mqtt.client:disconnect	():nil	Disconnect from the broker
mqtt.client:subscribe	(topic: string [, qos: number = 1]):nil	Subscribe to topic
mqtt.client:unsubscribe	(topic: string):nil	Unsubscribe from topic
mqtt.client:publish	(topic: string, data: string [, qos: number = 1] [, retry: number = 0]]):nil	Publish message

Example:

local mqtt = require("mqtt")

local client = mqtt.client("mqtt://broker.hivemq.com:1883")

client:setonconnect(function()
 client:publish("test/message", "Connected!")
end)

client:connect()

json module

This module JSON serialization & deserialization. Not globally loaded, need require this module.

Function	Signature	Description
json.encode	(table|number|boolean|string|nil[, formated: boolean]):string	Encode Lua value to JSON
json.decode	(string):table|number|boolean|string|nil	Decode from JSON to Lua value

Example:

local json = require("json")

local value = {
  num = 123,
  str = "abc",
  logical = true
}
print(json.encode(value, true))

Complex example

Here is example with two drivers, first handling emergency stop button, second sending telemetry data to thingsboard cloud. For better code readability, each driver is in its own script file, the main script init.lua imports them.

File /data/init.lua:

evse.adddriver(require("emstop"))
evse.adddriver(require("tb"))

Fili /data/emstop.lua:

local aux = require("aux")

return {
  every1s = function ()
    local emstop = aux.read("IN2")
    if not emstop ~= evse.getavailable() then
      evse.setavailable(not emstop)
    end
  end
}

File /data/tb.lua:

local mqtt = require("mqtt")
local json = require("json")

local client = mqtt.client("mqtt://demo.thingsboard.io:1883", "your password")

client:setonconnect(function()
  print("tb contected")
end)

client:connect()

function send()
  local payload = {}
  local state = evse.getstate()
  payload["session"] = (state >= evse.STATEB1 and state <= evse.STATED2) and 1 or 0
  payload["charging"] = (state == evse.STATE_C2 or state == evse.STATE_D2) and 1 or 0
  payload["enabled"] = evse.getenabled() and 1 or 0
  payload["power"]  = evse.getpower()
  payload["consumption"] = evse.getconsumption()
  payload["voltageL1"], payload["voltageL2"], payload["voltageL3"] = evse.getvoltage()
  payload["currentL1"], payload["currentL2"], payload["currentL3"] = evse.getcurrent()
  payload["temperature"] = evse.gethightemperature()
  payload["uptime"] = os.clock()

  client:publish("v1/devices/me/telemetry", json.encode(payload))
end

local counter = 0

return {
  every1s = function ()
    if counter == 60 then
      send()
      counter = 0
    end
    counter = counter + 1
  end
}