AI2 Inventor Forum News: ESP8266 Controlled with Android App (MIT App Inventor)

2017년 3월 29일 수요일

ESP8266 Controlled with Android App (MIT App Inventor)

DOWNLOAD FREE PDF: Getting Started with ESPlorer IDE and ESP8266

In this project, you’re going to build an Android app using the MIT App Inventor software that allows you to control the ESP8266 GPIOs.

First, watch the video demonstration

To learn more about the ESP8266 use the following tutorials as a reference:

If you like the ESP and you want to do more projects you can download my eBook Home Automation using ESP8266 here.

Let’s get started!

Parts List

Here’s the hardware that you need to complete this project:

1x ESP8266 (eBay)
1x FTDI programmer (eBay)
2x LEDs
2x 220Ω Resistors
1x Breadboard
1x Android Phone

Click the image above, to see on eBay.

Flashing Your ESP with NodeMCU

In this tutorial we are going to use the NodeMCU firmware. You have to flash your ESP with NodeMCU firmare.

Downloading ESPlorer IDE

I recommend using the ESPlorer IDE which is a program created by 4refr0nt to send commands to your ESP8266.

Follow these instructions to download and install ESPlorer IDE:

Click here to download ESPlorer
Unzip that folder
Go to the main folder
Run “ESPlorer.jar” file
Open the ESPlorer IDE

Schematics (3.3V FTDI Programmer)

The schematics for this project are very straight forward. You only need to establish a serial communication between your FTDI programmer and your ESP8266. You can buy one FTDI programmer on eBay.

Wiring:

RX -> TX
TX -> RX
CH_PD -> 3.3V
VCC -> 3.3V
GND -> GND

Uploading Code

RELATED CONTENT: Like ESP8266? Check out Home Automation Using ESP8266

You should see a window similar to the preceding Figure, follow these instructions to upload a Lua file:

Connect your FTDI programmer to your computer
Select your FTDI programmer port
Press Open/Close
Select NodeMCU+MicroPtyhon tab
Create a new file called init.lua
Press Save to ESP

Everything that you need to worry about or change is highlighted in red box.

Code

Upload the following code into your ESP8266 using the preceding software. Your file should be named “init.lua“.

Don’t forget to add your network name (SSID) and password to the script below.

-- Rui Santos
-- Complete project details at http://randomnerdtutorials.com

wifi.setmode(wifi.STATION)
wifi.sta.config("YOUR_NETWORK_NAME","YOUR_NETWORK_PASSWORD")
print(wifi.sta.getip())
led1 = 3
led2 = 4
gpio.mode(led1, gpio.OUTPUT)
gpio.mode(led2, gpio.OUTPUT)
srv=net.createServer(net.TCP)
srv:listen(80,function(conn)
    conn:on("receive", function(client,request)
        local buf = "";
        buf = buf.."HTTP/1.1 200 OK\n\n"
        local _, _, method, path, vars = string.find(request, "([A-Z]+) (.+)?(.+) HTTP");
        if(method == nil)then
            _, _, method, path = string.find(request, "([A-Z]+) (.+) HTTP");
        end
        local _GET = {}
        if (vars ~= nil)then
            for k, v in string.gmatch(vars, "(%w+)=(%w+)&*") do
                _GET[k] = v
            end
        end
        
        if(_GET.pin == "ON1")then
              gpio.write(led1, gpio.HIGH);
        elseif(_GET.pin == "OFF1")then
              gpio.write(led1, gpio.LOW);
        elseif(_GET.pin == "ON2")then
              gpio.write(led2, gpio.HIGH);
        elseif(_GET.pin == "OFF2")then
              gpio.write(led2, gpio.LOW);
        end
        client:send(buf);
        client:close();
        collectgarbage();
    end)
end)

view rawProjects/ESP8266_Controller.lua

Schematics

Now follow these schematics to create the circuit that controls two LEDs.

Your ESP IP Address

When your ESP8266 restarts, it prints in your serial monitor the ESP IP address. Save that IP address, because you’ll need it later.

In my case, the ESP IP address is 192.168.1.95. If you experience problems seeing your IP read this troubleshooting guide.

Creating the Android App with MIT App Inventor

MIT App Inventor is a drag-and-drop software that allows you to create a basic, but fully functional Android app within an hour or less.

Here’s how to edit the ESP8266 Controller app:

Click here to download .zip folder that contains .aia file
Unzip the folder
Go to MIT App Inventor
Click the “Create Apps” button on the top right corner
Go to the “Projects” tab and select “Import project (.aia)”

After importing the .aia file, you’ll be able to edit the app and see how the app was built.

Designer

The designer tab is where you can edit how the app looks. Feel free to change the text, change the colors, add buttons or add more features.

Blocks

The blocks section is where you can add what each button does and add logic to your app.

Click the image above to enlarge the figure

After finishing editing the app you can click the “Build” app tab and install the .apk file in your Android. I personally recommend that you first upload the app provided below to ensure that everything works as expected (later you can edit the app).