Error in code. Lua on NodeMCU - lua

Question

I have a motorized roller blind project.
I am following this instructable: https://www.instructables.com/id/Motorized-WiFi-IKEA-Roller-Blind/ .
I am using the code in the instructable, but I suspect tha fault is in one of these codes:
config.lua
-- file : config.lua
local module = {}
module.SSID = {}
module.SSID["ssid"] = "password"
-- example for local MQTT
--module.MQHOST = "ohab.local"
--module.MQPORT = 1883
--module.MQID = node.chipid()
--module.MQUSR = ""
--module.MQPW = ""
-- example for cloud MQTT
module.MQHOST = "192.***.*.*"
module.MQPORT = 1883
module.MQID = node.chipid()
module.MQUSR = "username"
module.MQPW = "password"
module.MQTLS = 1 -- 0 = unsecured, 1 = TLS/SSL
module.ENDPOINT = "/house/masterbedroom/rollerblind/"
module.ID = "0"
--module.SUB = "set"
module.SUB = {[module.ENDPOINT .. module.ID .. "/set"]=0,[module.ENDPOINT .. "all"]=0}
module.POST = module.ENDPOINT .. module.ID .. "/status"
return module
wifi_setup
-- file: setup.lua
local module = {}
local function wifi_wait_ip()
if wifi.sta.getip()== nil then
print("IP unavailable, Waiting...")
else
tmr.stop(1)
gpio.write(pin_led,1) --off
print("\n================== ==================")
print("ESP8266 mode is: " .. wifi.getmode())
print("MAC address is: " .. wifi.ap.getmac())
print("IP is "..wifi.sta.getip())
print("====================================")
mq.start()
end
end
local function wifi_start(list_aps)
if list_aps then
gpio.write(pin_led,0) --on
for key,value in pairs(list_aps) do
if config.SSID and config.SSID[key] then
wifi.setmode(wifi.STATION);
wifi.sta.config(key,config.SSID[key])
wifi.sta.connect()
print("Connecting to " .. key .. " ...")
--config.SSID = nil -- can save memory
tmr.alarm(1, 2500, 1, wifi_wait_ip)
end
end
else
print("Error getting AP list")
end
end
function module.start()
print("Configuring Wifi ...")
wifi.setmode(wifi.STATION);
wifi.sta.getap(wifi_start)
end
return module
Sadly I cant manage to go beyond step 4. After I have tried to download the code to the ESP8266 I only get this error:
PANIC: unprotected error in call to Lua API (wifi_setup.lua:25: bad argument #1 to 'config' (config table not found!))
I have only changed the stuff the instructable told me to change, and I have tried to look for faults myself but I cant find any... It's the first time I am using Lua, so this is totally new for me.
Hope somebody here can offer some help. Been stuck on this for days...
THIS PART OF THE PROBLEM IS SOLVED. CHECK COMMENTS FOR SOLUTION
Sadly when one problem is solved, a new one rises...
The chip is now successfully connecting to the wifi and mqtt service, but when I try to do the dry run by putting in the command 'step_move(1000,FWD,2)' nothing happens. The motor should rotate...
Also when I press the button I get a new panic error as follows:
PANIC: unprotected error in call to Lua API (button.lua:23: attempt to perform arithmetic on upvalue '?' (a nil value))
button.lua
--file button4.lua
do
-- use pin 1 as the input pulse width counter
local pin=5
local debounce = 150 --ms
local longpress = 2000 --ms
local pulse1, pulse2, du, now, trig = 1, 0, 0, tmr.now, gpio.trig
local prev_int_time, int_time, up_time = 0
local cal_steps = 100000
local cal_steps_dn = 0
local cal_steps_up = 0
local cal_state = 0 -- 0 = not calibration, 1 = calibrating down, 2 = calibrating up
state = 0 -- state: 0 = up, 1 = transition, 2 = down
gpio.mode(pin,gpio.INT)
local function pin4cb(level)
int_time = now() / 1000
if ((int_time - prev_int_time) > debounce) then
if (level == 0) then
up_time = int_time
else
if((int_time - up_time) > longpress) then
print("calibrating")
cal_state = 1
--cur_step = 100000
step_move(cal_steps,FWD,2)
else -- short press
print("short", cal_state)
if (cal_state == 2) then -- calibrated up (done)
print("calibration done")
state = 0 -- up
cur_step = 0
tot_steps = cal_steps - step_stepsleft
print("cal_steps: " .. cal_steps)
print("step_stepsleft: " .. step_stepsleft)
print("tot_steps: " .. tot_steps)
step_stop()
pins_disable()
cal_state = 0
if file.open("cfg_tot_steps.lua", "w+") then
file.write("tot_steps=" .. tot_steps .. '\n')
file.close()
end
elseif (cal_state == 1) then -- calibrated dn (switch direction)
print("calibration low point")
print(cal_steps - step_stepsleft)
step_stop()
step_move(cal_steps,REV,2)
cal_state = 2
elseif (cal_state == 0) then
if (state == 0 and step_stepsleft == 0) then -- i am up, go dowm
rollerblind.down()
-- state = 2
elseif (state == 1) then -- i am moving, do nothing
-- do nothing
elseif (state == 2 and step_stepsleft == 0) then -- i am down, go up
rollerblind.up()
-- state = 0
end
end
end
end
--print (level)
prev_int_time = int_time
end
end
gpio.trig(pin, "both", pin4cb)
end
Here is the code for the stepper.lua:
-- stepper.lua
-- code from: http://www.esp8266.com/viewtopic.php?f=19&t=2326
-- simple stepper driver for controlling a stepper motor with a
-- l293d driver
-- nodemcu pins: 0 5 6 7
stepper_pins = {1,3,2,4} -- (A-)blue, (A+)pink, (B-)yellow, (B+)orange
--stepper_pins = {1,2,3,4}
-- half or full stepping
step_states4 = {
{1,0,0,1},
{1,1,0,0},
{0,1,1,0},
{0,0,1,1}
}
step_states8 = {
{1,0,0,0},
{1,1,0,0},
{0,1,0,0},
{0,1,1,0},
{0,0,1,0},
{0,0,1,1},
{0,0,0,1},
{1,0,0,1},
}
step_states = step_states4 -- choose stepping mode
step_numstates = 4 -- change to match number of rows in step_states
step_delay = 10 -- choose speed
step_state = 0 -- updated by step_take-function
step_direction = 1 -- choose step direction -1, 1
step_stepsleft = 0 -- number of steps to move, will de decremented
step_timerid = 4 -- which timer to use for the steps
status_timerid = 2 -- timer id for posing of status messages
-- setup pins
function pins_enable()
for i = 1, 4, 1 do
gpio.mode(stepper_pins[i],gpio.OUTPUT)
end
end
function pins_disable()
-- for i = 1, 4, 1 do -- no power, all pins
for i = 2, 4, 1 do -- no power, all pins except one (to keep it in place)
gpio.mode(stepper_pins[i],gpio.INPUT)
end
end
-- turn off all pins to let motor rest
function step_stopstate()
for i = 1, 4, 1 do
gpio.write(stepper_pins[i], 0)
end
end
-- make stepper take one step
function step_take()
-- jump to the next state in the direction, wrap
step_state = step_state + step_direction
cur_step = cur_step + step_direction * FWD
if step_state > step_numstates then
step_state = 1;
elseif step_state < 1 then
step_state = step_numstates
end
-- write the current state to the pins
pins_enable()
for i = 1, 4, 1 do
gpio.write(stepper_pins[i], step_states[step_state][i])
end
-- might take another step after step_delay
step_stepsleft = step_stepsleft-1
if step_stepsleft > 0 then
-- if cur_step > 0 and cur_step < tot_steps and step_stepsleft > 0 then
tmr.alarm(step_timerid, 10, 0, step_take )
--tmr.alarm(step_timerid, 10, 0, step_take )
else
step_stopstate()
step_stop()
pins_disable()
mq.post_status()
if file.open("cfg_cur_step.lua", "w+") then
file.write("cur_step=" .. cur_step .. '\n')
file.close()
end
end
end
-- public method to start moving number of 'int steps' in 'int direction'
function step_move(steps, direction, delay)
tmr.stop(step_timerid)
step_stepsleft = steps
step_direction = direction
step_delay = delay
step_take()
end
function step_go_to(step, delay)
if step >= cur_step then
steps = step - cur_step
step_move(steps, FWD, delay)
end
if step <= cur_step then
steps = cur_step - step
step_move(steps, REV, delay)
end
end
function percent_go_to(percent, delay)
if(percent >= 0 and percent <= 100) then
step_stop()
tmr.register(status_timerid, 1000, tmr.ALARM_AUTO, function () mq.post_status() end)
tmr.start(status_timerid)
step = percent * tot_steps / 100
step_go_to(step, delay)
end
end
-- public method to cancel moving
function step_stop()
tmr.stop(step_timerid)
tmr.stop(status_timerid)
step_stepsleft = 0
step_stopstate()
end

Answer 1

Let's parse the error message one by one:
unprotected error in call to Lua API (wifi_setup.lua:25: bad argument #1 to 'config' (config table not found!))
Unprotected error means that you did a normal function call, as opposed to a protected call (aka pcall), which is a function call where you expect errors to occur and want to provide means to handle them. Since you did not do a protected call, Lua does not know how to handle the error and terminates right away (which is not a bad thing).
wifi_setup.lua:25 tells you the file and line at which the error occured.
bad argument #1 to 'config' means that the problem is due to the first argument passed to a function named config.
config table not found! is the error message provided by the implementer of that function.
So in summary, there is a problem with the function call wifi.sta.config(key,config.SSID[key]) as it expects a table as first argument, while you provided something different (ie. a string with the BSSID). Indeed checking with the NodeMCU docs shows that you need to pass a table to this function:
wifi.sta.config()
Sets the WiFi station configuration. [...]
Syntax
wifi.sta.config(station_config)
Parameters
station_config table containing configuration data for
station
The expected layout of the table is documented in detail on that page as well.

Answer 2

ComicSansMS provided a great answer the essence of which is that you need to replace
wifi.sta.config(key,config.SSID[key])
with
wifi.sta.config{ssid=key,pwd=config.SSID[key]}
Thus a standalone example could be like this:
--wifi.setmode(wifi.NULLMODE)
config = {}
config.SSID = {}
config.SSID["ssid"] = "password"
function wifi_wait_ip()
if wifi.sta.getip() == nil then
print("IP unavailable, Waiting...")
else
tmr.stop(1)
print("\n====================================")
print("ESP8266 mode is: " .. wifi.getmode())
print("MAC address is: " .. wifi.ap.getmac())
print("IP is " .. wifi.sta.getip())
print("====================================")
end
end
function wifi_start(list_aps)
if list_aps then
for key, value in pairs(list_aps) do
if config.SSID and config.SSID[key] then
wifi.setmode(wifi.STATION);
wifi.sta.config{ssid=key, pwd=config.SSID[key]}
-- wifi.sta.connect() not needed as config() uses auto-connect=true by default
print("Connecting to " .. key .. " ...")
tmr.alarm(1, 2500, 1, wifi_wait_ip)
end
end
else
print("Error getting AP list")
end
end
function start()
print("Configuring Wifi ...")
wifi.setmode(wifi.STATION)
wifi.sta.getap(wifi_start)
end
start()