Wednesday, May 27, 2015

Raspberry PI - Standalone Thingspeak Server installation



UPDATE !! UPDATE !! UPDATE !! UPDATE !!

New fresh install instructions based on the new RASPBIAN Jessie: Raspberry PI2 + Thingspeak Server on RASPBIAN Jessie

-------------------------------------------------------------------------------------------------

Original Article

     As you might read already in my previous  ESP8266 Battery Monitor System  post I was using Thingspeak.com, because of it's flexibility, as a logger for live data uploading.
In the latest week I was exploring deeper Thigspeak capabilities.

   As you know, Thinspeak.com it's a open source project, and you have full access to the project sources on Github 

   What I was interested for was to check the possibility to build/configure and use a standalone Thingspeak Server that can run independently of Internet infrastructure on a small footprint, low power consumption platform.
   The interesting part regarding the Thingspeak Server deployment is the chosen platform, the new RASPBERRY PI 2 Board!


 



    I will present you below the step-by-step process to install your own RPI Thingspeak Server that can be tailored on your own needs and ofcourse, not affected by Internet connection availability and uptime if installed in the same physical location/LAN as your ESP8266 BMS or any sensor grid/array you might want to use with!






INSTALLATION PROCESS:


1.  Install a Raspberry Pi Operating System image on SD card

  •  Download the Raspbian image from RPI website
  •  Write image to SDCard
    For more details please read RPI Install Guide

I was using the Win32DiskImager utility under W7Pro for that, worked like a charm.




2. First RPI RUN with the new SDCard:


  • Inset card in RPI2
  • Boot 
  • From raspi-config:
              - Set to use entire SDcard space
              - Set hostname: RPIMON1
              - Enable SSH Server
              - Write down your new RPI IP: 192.168.2.xx

  • Reboot for apply new hostname & settings
                pi@RPIMON1~$ sudo reboot



3. System Update & required packages install
  • Switch over to SSH remote access with Putty - accept new key


  • Change "pi" account password:
                  pi@RPIMON1~$passwd
  • Set ROOT password, so you can then use root (just for very, very special things!)
              pi@RPIMON1~$sudo passwd root

  • System Update & upgrade  :
              pi@RPIMON1~$sudo apt-get update            
              pi@RPIMON1~$sudo apt-get upgrade          
              pi@RPIMON1~$sudo apt-get dist-upgrade   
              pi@RPIMON1~$sudo sync

  • Reboot:
            pi@RPIMON1~$ sudo reboot


  • Required packages:
           pi@RPIMON1~$sudo apt-get -y install build-essential git mysql-server mysql-client 
                                       libmysqlclient-dev libxml2-dev libxslt-dev libssl-dev libsqlite3-dev


4.  MySQL Database configuration


pi@RPIMON1~$mysql --user=root mysql -p useyourpasswd here
pi@RPIMON1~$mysql> CREATE USER 'thing'@'localhost' IDENTIFIED BY 'speak’;
pi@RPIMON1~$mysql> GRANT ALL PRIVILEGES ON *.* TO 'thing'@'localhost' WITH GRANT OPTION;
pi@RPIMON1~$mysql> commit;
pi@RPIMON1~$mysql> exit;




5.  Ruby & Rails install

          pi@RPIMON1~$wget http://cache.ruby-lang.org/pub/ruby/2.1/ruby-2.1.5.tar.gz
          pi@RPIMON1~$tar xvzf ruby-2.1.5.tar.gz
          pi@RPIMON1~$cd ruby-2.1.5
          pi@RPIMON1~$./configure
          pi@RPIMON1~$make
          pi@RPIMON1~$sudo make install
          pi@RPIMON1~$cd ..
          pi@RPIMON1~$echo "gem: --no-rdoc --no-ri" >> ${HOME}/.gemrc
          pi@RPIMON1~$sudo gem install rails




 6.  THINGSPEAK SERVER INSTALL

pi@RPIMON1~$git clone https://github.com/iobridge/thingspeak.git
pi@RPIMON1~$cp thingspeak/config/database.yml.example thingspeak/config/database.yml
pi@RPIMON1~$cd thingspeak
pi@RPIMON1~$bundle install
pi@RPIMON1~$bundle exec rake db:create

pi@RPIMON1~$mysql --user=root mysql -p
pi@RPIMON1~$mysql> show databases;
pi@RPIMON1~$mysql> exit;





IF all OK continue with loading Thingspeak DB configuration

pi@RPIMON1~$bundle exec rake db:schema:load




RUN the THINGSPEAK SERVER:

pi@RPIMON1 ~/yourthingspeak $ rails server webrick






And the result in Browser:

Running Thingspeak on RPI Board

Create new Thingspeak USER:

Thingspeak Signup page


Create new CHANNEL

Create new channel for ESP8266 BMS data upload


Live Data update:

ESP8266 BMS  - Live data upload


UPDATE !! UPDATE !! UPDATE !! UPDATE !!

New fresh install instructions based on the new RASPBIAN Jessie: Raspberry PI2 + Thingspeak Server on RASPBIAN Jessie




Monday, May 18, 2015

P2 - Battery Monitor System - Web Server and data upload



 ================== W A R N I N G ! ! =================
Li-Ion batteries are very dangerous if not handled properly.
Use them only with proper protection circuits and chargers.
DO NOT OVER CHARGE / BURN / OPEN Li-Ion Bats
     Using any of the informations available on esp8266-projects.com
 is on your own risk !!
===============================================
 
    For any new CBDBv2 Evo orders/requests please feel free to use as usual:
     tech at esp8266-projects.com.
     If you want for your own experiments to order CBD v2 EVO bare PCBs only, you can also do it directly at Dirty PCBs, our preferred PCB House:
  http://dirtypcbs.com/view.php?share=5876&accesskey=3d0fd70d53d6dc20c0bf0255f67cde65
------------------------------------------------------------------------------------------------------------------



As promised, today we will continue with our Live Battery Monitor System.


Subjects of the day:
  •  WebServer interface for direct access
  •  Live Data upload over the Internet for wordwide access on Thingspeak.com.


What we will need:  

For schematics, theory of operation and technical related things please see previous article: Battery LIve Monitor System




BLMS Software
 
  For programming CBDBv2 Board and uploading the drivers and the software we will continue to use the LuaUploader as before.




1. Define used GPIO pins and variables:

ADC_SRC = 5                    -- GPIO14 - select Voltage Divider / Current Inputsda=2                                   -- GPIO4  - SDA
scl=1                                    -- GPIO5  - SCL
gpio.mode(ADC_SRC,gpio.OUTPUT, gpio.PULLUP)
gpio.write(ADC_SRC,1)      -- Voltage Measurement - Voltage Divider Source selected
gpio.write(ADC_SRC,0)      -- Current Measurement - Current Shunt Monitor output selected
voltdiv= 0.00412                -- Voltage reading calibration
dival = 0.00096                  -- ADC volt/div value - CALIBRATE !! 
resdiv = 4.31447                -- Voltage Divider Ratio - CALIBRATE!!
divalI = 0.9425                  -- Current volt/div ratio - CALIBRATE!!
cpct = 0                              -- Calculated Delivered Energy
adcI = 0                             -- ADC readings -  Curent

adcV = 0                            -- ADC readings - Voltage
pwr = 0                              -- Calculate Power
t=0                                     -- time  





2. READ ADC Process function  and calculations 

function readUI()

   gpio.write(ADC_SRC,1)
      advr=adc.read(0)
      adcV=advr*dival*resdiv
      print("\nVoltage     : " ..string.format("%g",adcV).." V")


   tmr.delay(10000)
   gpio.write(ADC_SRC,0)
      adcr=adc.read(0)
      adcI=adcr*divalI
      print("Current     : " ..string.format("%g",adcI).." mA")
   --instantaneous Power consumption calculation
   pwr = adcI*adcV
   print("Power       : " ..string.format("%g",pwr).." mW")

   -- total delivered Energy calculation
    if (adcV > 1) then
      cpct=cpct+pwr*0.002778/1000
      t = t +1
       print("Energy      : " ..string.format("%g",cpct).." W")
  else  tmr.stop(0)
        dtime = t/360         -- calculate discharge time

        print("Discharge Time: %.2fh  ",dtime)
  end
end



3. BMS WebServer

srv=net.createServer(net.TCP)
  srv:listen(80,
     function(conn)
        conn:on("receive",function(conn,payload)
        --print(payload)
        conn:send("HTTP/1.1 200 OK\n\n")
        conn:send("<META HTTP-EQUIV=\"REFRESH\" CONTENT=\"5\">")
        conn:send("<html><title>Battery Live Monitor System - ESP8266</title><body>")
        conn:send("<h1>Battery Live Monitor System - ESP8266</h1><BR>")
        conn:send("Voltage :<B><font color=red size=4>" 

                          ..string.format("%g",adcV).." V</font></b><br>")
        conn:send("Current :<B><font color=blue size=4>"

                         ..string.format("%g",adcI).." mA</font></b><br>")
        conn:send("Power   :<B><font color=red size=4>"

                        ..string.format("%g",pwr).." mW</font></b><br>")
        conn:send("Energy  :<B><font color=green size=4>"

                       ..string.format("%g",cpct).." Wh</font></b><br>")
        conn:send("<BR><BR><BR>Node.HEAP     : <b>" .. node.heap() .. "</b><BR>")
        conn:send("IP ADDR    :<b>".. wifi.sta.getip() .. "</b><BR>")
        conn:send("TMR.NOW    :<b>" .. tmr.now() .. "</b><BR<BR><BR>")
        conn:send("</html></body>")
        conn:on("sent",function(conn) conn:close() end)
        conn = nil    
      end)
end)
 



4. Thingspeak.com data upload  

 function sendDataTh()
    print("Sending data to thingspeak.com")
    conn=net.createConnection(net.TCP, 0)
        conn:on("receive", function(conn, payload) print(payload) end)
        conn:connect(80,'184.106.153.149')
        conn:send("GET /update?key=YOURKEYHERE&field1="..adcV.."&field2="..adcI.."&

                           field3="..pwr.."&field4="..cpct.."HTTP/1.1\r\n")
        conn:send("Host: api.thingspeak.com\r\n")
        conn:send("Accept: */*\r\n")
        conn:send("User-Agent: Mozilla/4.0 (compatible; esp8266 Lua; Windows NT 5.1)\r\n")
        conn:send("\r\n")
        conn:on("sent",function(conn) print("Closing connection")
        conn:close()
    end)
    conn:on("disconnection", function(conn) print("Got disconnection...")
    end)
end





5. MAIN program


If you have a new ESP module or is the first time when using it on a new WIFI network, don't forget to do the WIFI setup:

        -- One time ESP Setup --
        wifi.setmode(wifi.STATION)
         wifi.sta.config ( "YOUR_WIFI_SSID" , "PASSWORD" ) 
         print(wifi.sta.getip())



-- Read ADC data every 10s, print values on local Web interface and send them to thingspeak.com
 tmr.alarm(0, 10000, 1, function() readUI() sendDataTh() end)




   For testing, just save the code on ESP as 'blmsweb.lua', restart ESP and run:   
  
            dofile("blmsweb.lua")      -- Start the Battery Live Monitoring System

            print(wifi.sta.getip())       --print your BMS WebServer IP address





BLMS - First RUN

  If you want the BLMS software to start automatically when your CBDBv2 Evo Board starts or reboots, then you neet to create and add some lines in your 'init.lua' file:
  
            dofile("blmsweb.lua")      -- Start the Battery Live Monitoring System

Save the code on ESP as 'init.lua', restart ESP. It should reboot and restart automatically the program.




Open your favorite Web browser and type your new BLMS Web Server IP address. If all ok, it should look like below :

 
BLMS - Web Server interface - 20ohm Load




Thingspeak data upload

I will not insist on the Thingspeak.com account setup, it's a pretty simple process:
  1. Sign Up for a ThingSpeak account
  2. Create a new Channel by going to your Channels page and clicking Create New Channel
  3. Update your Channel via URL:
    https://api.thingspeak.com/update?api_key=YOUR_CHANNEL_API_KEY&field1=7
  4. View your Channel feed:
    https://api.thingspeak.com/channels/YOUR_CHANNEL_ID/feeds.json
Take a look at this Tutorial for more details for common devices and applications



Thingspeak.com live data uploaded - 10ohm/10W Load for stress test calibration




You can also see on graph below the moment when battery protection kicks in, around 2.4V, 2.37745 V in this case, to be more exactly:




In the video below live monitoring data, with 10 and 20ohm resistor Load:






Thursday, May 14, 2015

Battery Live Monitor System - ESP8266 CBDBv2


 ================== W A R N I N G ! ! =================
Li-Ion batteries are very dangerous if not handled properly.
Use them only with proper protection circuits and chargers.
DO NOT OVER CHARGE / BURN / OPEN Li-Ion Bats
     Using any of the informations available on esp8266-projects.com
 is on your own risk !!
===============================================


     For any new CBDBv2 Evo orders/requests please feel free to use as usual:
     tech at esp8266-projects.com.
     If you want for your own experiments to order CBD v2 EVO bare PCBs only, you can also do it directly at Dirty PCBs, our preferred PCB House:

  http://dirtypcbs.com/view.php?share=5876&accesskey=3d0fd70d53d6dc20c0bf0255f67cde65


------------------------------------------------------------------------------------------------------------------


      One of the main problem in battery powered projects is to choose/use the proper battery size/model/type. As market is flooded now with a lot of low quality batteries claiming thousands of mAh ( Ultrafire fakes stories is just an example) the only way to proper check them is to run a set of tests.
   
    A simple basic capacity test / loading / discharging time values can give you valuable informations about the parameters and health of the battery. And of course also you can see how are looking the numbers against the datasheet claims :).


  Few general considerations that I want to bring to your attention:
  • The capacity of a battery tells you how much charge it can store.  This means that they can theoretically provide a current of 2A for one hour, 1A for two hours, or 200mA for ten hours. In reality a 2,000mAh battery would not provide 20mA for 100 hours, nor 2A for one hour. 
  • Discharge load -  this is a tricky one and most of the time not clear explained by battery manufacturers in their datasheets. Mostly of them are using a discharge load of 0.1C, that means one-tenth of current capacity when rating their batteries. Therefore, a battery which can provide 200mA for 10 hours would be rated at 10x200 = 2,000mAh !!   
         A faster discharge rate would result in less energy being extracted from the battery, and
         therefore the measured capacity would be lower. If you are using batteries in energy-hungry
         devices that need more than 0.1C, the real capacity will be lower than that published.




     A "good-to-have" add-in for a battery powered project is a system that will be able to monitor over the entire battery lifetime at least few parameters like, voltage, current, power consumption and stored energy between charges. 


   What we will need:  


   Schematics:

  As the CBDBv2 Evo DevBoard has already Voltage and Current measurements capabilities onboard, the only thing that we will need to do is to connect the battery module that we want to measure to the board:



           GREEN  - V+
           BLUE    -  GND
           RED      -  SH_IN+
           WHITE -  SH_IN-



    By default the CBDBv2 Evo Board comes prepared for Li-Ion batteries voltage range, with the onboard default voltage divider values and Rshunt you have VmaxIN=4.3V and ImaxIN = 1A. If you need a different Voltage/Current range just change/ask for different default values.


CBDB v2 Evolution DevBoard with INA21x Current monitor


    The Current shunt monitor used for this project is a INA21x family one. 

    The INA210, INA211, INA212, INA213, INA214, and  INA215 are voltage-output, current-shunt monitors that can sense drops across shunts at common-mode voltages from –0.3 V to 26 V, independent of the supply voltage. 

   
    Five fixed gains are available: 50 V/V, 75 V/V, 100 V/V, 200 V/V, 500 V/V, or 1000 V/V. 
    The low offset of the zero-drift architecture enables current sensing with maximum drops across the shunt as low as 10-mV full-scale.
 

   These devices operate from a single 2.7-V to 26-V power supply, drawing a maximum of 100 μA of supply current. All versions are specified over the extended operating temperature range (–40°C to 125°C), and offered in an SC70 package. The INA210, INA213, and INA214 are also offered in a thin UQFN package.


 INA21x Features:

• Wide Common-Mode Range: –0.3 V to 26 V
• Offset Voltage: ±35 μV (Max, INA210) (Enables Shunt Drops of 10-mV Full-Scale)
• Accuracy:
– ±1% Gain Error (Max over Temperature)
– 0.5-μV/°C Offset Drift (Max)
– 10-ppm/°C Gain Drift (Max)
• Choice of Gains:
– INA210: 200 V/V
– INA211: 500 V/V
– INA212: 1000 V/V
– INA213: 50 V/V
– INA214: 100 V/V
• Quiescent Current: 100 μA (max)



     For any new CBDBv2 Evo orders/requests please feel free to use as usual: tech at esp8266-projects.com.
     If you want for your own experiments to order CBDBv2 EVO bare PCBs only, you can also do it directly at the PCB House:  

  http://dirtypcbs.com/view.php?share=5876&accesskey=3d0fd70d53d6dc20c0bf0255f67cde65



    For that ones of you that want to use a different Board or just want to add these functions to a ESP8266 Module, you just need:
  • for Voltage -  add and size on your needs the voltage divider as explained in details in the previous article about ESP8266 Internal ADC. 
  • for Current - add your favourite Current Monitor but don't forget about the VmaxIN for ESP8266 ADC of about 1V!




   BLMS Software
 
  For programming CBDBv2 Board and uploading the drivers and the software we will continue to use the LuaUploader as before.


   How to Measure Battery Capacity

   When measuring the real battery capacity what we are interested in is the amount of energy stored in a battery since it is this energy we need to power our devices. Stored energy is measured in Watt-hours - the same unit used to measure our domestic electricity consumption (where 1,000Wh = 1kWh = 1 unit of electricity).

   In order to measure the stored energy in a battery a power resistor is used as the load, and a fully charged battery is fully discharged through it. By measuring the voltage across this resistor at regular intervals during the discharge process it is simple to calcuate the total energy dissipated and therefore the total energy which had been stored in the battery.

  Using Ohm's Law (I=U/R) we can then calculate the current flowing through the load since we know the voltage across it. Instantaneous power is given by multiplying the measured voltage by the calculated current (P=U*I).

   By taking readings for a certain amount of time until the battery is completely discharged, and adding up the energy dissipated in each time interval, we can calculate the total energy taken from the battery and dissipated in the resistor and therefore the total energy that was stored in the fully charged battery.



Software Implementation
 
1. Define used GPIO pins and variables:

ADC_SRC = 5                    -- GPIO14 - select Voltage Divider / Current Inputsda=2                                   -- GPIO4  - SDA
scl=1                                    -- GPIO5  - SCL

gpio.mode(ADC_SRC,gpio.OUTPUT, gpio.PULLUP)

gpio.write(ADC_SRC,1)      -- Voltage Measurement - Voltage Divider Source selected
gpio.write(ADC_SRC,0)      -- Current Measurement - Current Shunt Monitor output selected
 

voltdiv= 0.00412                -- Voltage reading calibration
dival = 0.00096                  -- ADC volt/div value - CALIBRATE !! 
resdiv = 4.31447                -- Voltage Divider Ratio - CALIBRATE!!
divalI = 0.9425                  -- Current volt/div ratio - CALIBRATE!!
cpct = 0                              -- Calculated Delivered Energy
adcI = 0                             
-- ADC readings -  Curent

adcV = 0                            -- ADC readings - Voltage
pwr = 0                              -- Calculate Power
t=0                                     -- time 
 


2. READ ADC - Voltage  

function readADC_Voltage()
      adcV = 0
      advr = 0
      advr=adc.read(0)
      print("\nADCV Step   : " ..string.format("%g",advr).." steps")
      adcV=advr*dival*resdiv
      print("Voltage     : " ..string.format("%g",adcV).." V")
      return adcV
end


 

2. READ ADC - Current
    
function readADC_Current()
      adcI = 0
      adcr = 0
      adcr=adc.read(0)
      adcI=adcr*divalI
      print("ADCI Step   : " ..string.format("%g",adcr).." steps")
      print("Current     : " ..string.format("%g",adcI).." mA")
      return adcI
end


 

2. READ ADC Process function  and instantaneous Power consumtion calculation 

function readUI()
   gpio.write(ADC_SRC,1)         --select source
   adcV = readADC_Voltage()
   tmr.delay(10000)
   gpio.write(ADC_SRC,0)         
--select source
   adcI = readADC_Current()
   pwr = adcI*adcV
   print("Power       : " ..string.format("%g",pwr).." mW")
end

 


3. Number format function for proper LCD printing
  
nr_format = function (fnr,unit)
   if (fnr > 1000) then fnri=fnr/1000
                        uniti=string.sub(unit, 2)  
                        nrf=string.format(" %.3f%s ",fnri, uniti)
   else
   if (fnr < 100) then
                    if (fnr < 10) then
                                   nrf = string.format("  %.1f%s ",fnr, unit)
                      else nrf = string.format(" %.1f%s ",fnr,unit)
                    end
    else nrf = string.format("%.1f%s ",fnr,unit)
   end
  end   
   return nrf
end




4. LCD Print - > Voltage / Current / Energy / Power

    For more details about the I2C LCD Driver , please take a look at the ST7032i LCD Driver Article
 

LCDout = function()
   if (t==0) then st7032i:lcd_clear() end
   if (adcV > 1) then
      st7032i:lcd_print(1,1,string.format("%.3fV",adcV))
      adci = nr_format(adcI,"mA")
      st7032i:lcd_print(8,1,adci) 
      pwrp = nr_format(pwr,"mW")
      st7032i:lcd_print(0,2,pwrp)
      cpct=cpct+pwr*0.002778 --every 10 sec readings
      cpctp = nr_format(cpct,"mWh")
      t = t +1
      st7032i:lcd_print(8,2,cpctp)
  else  tmr.stop(0)
        dtime = t/360
        st7032i:lcd_print(0,1,string.format("Disc.Time:%.2fh ",dtime))
        st7032i:lcd_print(0,2,"Energy: ")
  end
end  


 

5. MAIN program

require('st7032i')
st7032i:init_i2c(sda,scl)
st7032i:init_LCD()
st7032i:lcd_clear()
st7032i:lcd_print(1,1,string.format("Battery Monitor"))
st7032i:lcd_print(3,2,string.format("Starting ..."))
 

tmr.alarm(0, 10000, 1, function() readUI() LCDout() tmr.delay(1000) end)




   For testing, just save the code on ESP as 'blms.lua', restart ESP and run:   
  

            dofile("blms.lua")      -- Start the Battery Live Monitoring System


Running BLMS program






    If you want the BLMS software to start automatically when your CBDB module starts or reboots, then you neet to create and add some lines in your 'init.lua' file:
  
            dofile("blms.lua")      -- Start the Battery Live Monitoring System

Save the code on ESP as 'init.lua', restart ESP. It should reboot and restart automatically the program.







That's all for today, next time we will continue with Web Interface and online logging system for the BLMS!


Thursday, May 7, 2015

MPDMv3 - WIFI Mains Power Dimmer / Switch - Web Interface



----------------------------------------------------------------------------------------------------------------------------


WARNING!! You will play with LIVE MAINS!! Deadly zone!! 


      If you don't have any experience and are not qualified for working with MAINS power I will not encourage you to play arround!. The author take no responsibility for any injury or death resulting, directly or indirectly, from your inability to appreciate the hazards of household mains voltages.
   The circuit diagrams are as accurately as possible, but are offered with no guarantees whatsoever. 
    There is no guarantee that this design meets any Rules which may be in force in your country so please check before your local rules/regulations.

----------------------------------------------------------------------------------------------------------------------------  

     For any new requests please feel free to use as usual: tech at esp8266-projects.com.
 
     If you want to order MAINS POwer Dimmer/Switch bare PCBs only, you can also do it directly at Dirty PCBs, our preferred PCB House:

-----------------------------------------------------------------------------------------------------------------------------


     As I promised in the last article about the new MAINS Dimmer / Switch Module, Today we will continue with designing the Web interface access.


      What we will need:  


MAINS Power Dimmer / Switch Module - MPDMv3 - Connections



CBDB Evolution DevBoard


     Because I don't like to have flying MAINS wires on my workdesk I have created a temporary separate MPDMv3 Module Box, containing all the MAINS part of the story :).

Isolated MAINS unit - keep your fingers away from the Deadly zone !


      Remember, Safety First! And also more relaxing knowing that is no Russian Roulette wire game on progress on my table. Shit happens all the time, but at least let's try to reduce the chances to hit badly the fan too often :)


Live Testing on progress

   In the Box above is enough space for all the parts going inside, including ESP8266 module, power supply, Dimmer Module, Choke, etc, but at this stage I find it easier to connect them together like that.



MPDMv3 Web Server Software

For programming CBDBv2 Board and uploading the driver and the software we will continue to use the LuaUploader as before. 


1. Define used GPIO pin
:

      outpin=7                                                       -- Select Triac Command pin - GPIO13
      gpio.mode(outpin,gpio.OUTPUT)
      gpio.write(outpin,gpio.LOW)                       -- Triac OFF
      inpin=6                                                         -- Zero crossing detector input - GPIO12 
      gpio.mode(inpin,gpio.INT,gpio.PULLUP)   -- attach interrupt to ZCD





  2. Zero Cross Detector function and Triac command


      For a more detailed explanation how Zero cross detection circuit works please take a look at the previous MPDMv3 article.

      function zero_cross()
           dt = 76*dim
           --print("Zero cross detected!")
           stat = "ON"
           tmr.delay(dt)                                 -- Firing delay time calculated above
           gpio.write(outpin,gpio.HIGH)     -- Triac ON - Zero cross detected
           tmr.delay(100)                              -- Triac ON - Propagation time 
          gpio.write(outpin,gpio.LOW)        -- Triac OFF - let's be sure it's OFF before next cycle :)
          tmr.wdclr()
          return stat
     end




3. WEB Server

srv=net.createServer(net.TCP)
srv:listen(80,function(conn)
   conn:on("receive", function(conn,payload)
      --debugging output only
      -- print(payload)
      if (string.find(payload, "GET / HTTP/1.1") ~= nil) then
         --print("GET received")
         sendPage(conn)
      else
         swstat={string.find(payload,"cmd=")}
         --If POST value exist, set power switch status
         if swstat[2]~=nil then
            --print("Command received: " .. payload)
            PwrSW(swstat,payload)
            sendPage(conn)
         end
      end
   end)
   conn:on("sent", function(conn)
      conn:close()
      conn = nil -- clear and allow the garbage collector to free the memory
      --print("Connection closed")
     
   end)
end)

 


4. Send page function based on received requests

function sendPage(conn)
   conn:send('HTTP/1.1 200 OK\n\n')
   conn:send("<META HTTP-EQUIV=\"REFRESH\" CONTENT=\"5\">")
   conn:send('<!DOCTYPE HTML>')
   conn:send('<html>')
   conn:send('<head><meta content="text/html; charset=utf-8">')
   conn:send('<LINK href="http://www.instructables.com/files/orig/FGU/L48I/I98BK1X6  

                       /FGUL48II98BK1X6.css"')
   conn:send('rel="stylesheet" type="text/css">')
   conn:send('<title>ESP8266 - Power Switch Controller</title></head>')
   conn:send('<body><center><h1>ESP8266 MAINS Power Dimmer Controller</h1></center>')
   conn:send('<br /><br />')
   conn:send('<form action="/" name="dimmer" oninput="outputUpdate(cmd.value)" 

                     method="POST">')
   conn:send('<font color=red><b>ON </b></font><input style="width:550px; height:50px" 

                     type="range" name="cmd" id="cmd" value="')
   conn:send(status)
   conn:send('" min=1 max=128 step=1 />')
   conn:send('<font color=red><b>OFF</b></font></form>')
   conn:send('<br><center>Dimmer Value: <b>')        
      conn:send(status)
      conn:send(' pts</b></center>')
   conn:send('<script type="text/javascript">')
   conn:send('function outputUpdate(dim) {document.querySelector("#cmd").value = dim;')
   conn:send('document.forms[0].submit();}</script>')
   conn:send('</body></html>')
end

 

 CSS file created for this example is just for fancy decorations. If you don't like it you can very easy change the style attributes or add local ones.



5. Check received Dimmer value and update status

     function PwrSW(swstat,payload)
           gpio.mode(outpin,gpio.OUTPUT)
           newstat=string.sub(payload,swstat[2]+1,#payload)
           status = tonumber(newstat)
           print("Dimmer Value:" ..  status)
    end






4. Main code

       status = 60                   -- around 50% - choose your desired start value.
       newstat = 60
        outpin=7                     -- Select Triac Command pin - GPIO13  
        gpio.mode(outpin,gpio.OUTPUT)
        gpio.write(outpin,gpio.LOW)  -- Triac OFF
        inpin=6                      -- Zero crossing detector input - GPIO12 
        gpio.mode(inpin,gpio.INT,gpio.PULLUP)  -- attach interrupt to ZCD
 

       gpio.trig(inpin,"up",zero_cross)                 -- ZCD interrupt attached - trigger on falling edge
       print(wifi.sta.getip())                                  -- print our new MPDMv3 WebServer IP



      For testing, just save the code on ESP as 'dimserver.lua', restart ESP and run:   
 
            dofile("dimserver.lua")      -- Start the Dimmer Listening WebServer
               =wifi.sta.getip()              -- find the IP Address where your Web Server will be

  

     Open your favorite Web browser and type your new MPDMv3 Web Server IP address. If all ok, should look something like below :

MPDMv3 Web Interface



If you want the MPDMv3 software to start automatically when your CBDB module starts or reboots, then you neet to create and add some lines in your 'init.lua' file:
  
          dofile("dimserver.lua")  -- Start automatically the Dimmer Listening WebServer



Save the code on ESP as 'init.lua', restart ESP. It should reboot and restart automatically the program.



A short video presentation, testing the Web Interface: