DEV Community: Iago

Arduino remotely controlled (part 3)

Iago — Tue, 03 Oct 2023 23:14:44 +0000

Introduction

In the previous post, we created a server to talk with an Arduino.

Now it's time to create a simple mobile application to interact with the server.

What are the problems I want to solve?

I don't want to interact with my Arduino using URLs. I want to interact with a nice (?) UI.

What is the solution?

Create an React Native + Expo application to connect and interact with the server.

Weak points

I'm not doing a very complex and fully working application. It's just a POC.
Ideally each interaction with the 'slider' should take some milliseconds before calling the server to avoid multiple callings
1. Now I'm thinking of making a change into the Arduino library to make percent values change into steps to make it smooth.
I'm not storing/recovering the server IP into the application. I'm sure you can do it easily.

Intended public

I expect you to have some knowledge of: Typescript, React, React Native and Expo.

Let's start

Code

I created tag into the app repository, so you just have to download and read the code.

What is the code idea?

It waits for user input the server URL or IP
Tests the connection
Loads the server data
Shows the hubs components
1. Waits for user interaction to send the value back to Arduino

Results

It's running in my old Android 7 smartphone. The screen is damaged and I had to do multiple touches to make the buttons work. I didn't want a long video, so I cropped some parts of it.

Previous steps

Last words

This project is far from complete.
It's NOT intended to be used in production as is.
It needs lots of refactoring (that I intend to do, and I'll keep the tags for everyone who's reading this tutorial)
Maybe someday, after all refactoring, I'll connect my Arduino to an solid state relay and do some 220V tests (children, don't try this)
If you did try my code, please let me know if it worked, any problems you faced and how you got around those issues
And last but not least, if you got this far, thank you for your patience

Arduino remotely controlled (part 2)

Iago — Sat, 30 Sep 2023 19:16:21 +0000

Introduction

In the previous post, we learned how to create an Arduino hub using the Simple Repository IO library.

Now it's time to make it talk with an server.

What are the problems I want to solve?

I want to create Arduino Hubs with actuators and sensors, but they must be controlled remotely.
This will (?) ease my mind that wants to create something.

What is the solution?

After creating an Arduino library, I must create a server to do the remote communication.

Weak points

The server is intended to run on your LAN only
1. You can do changes to make it work on the WEB
~~I'll create an NPM library to make it easier to call the commands without duplicating code over your servers' code.~~ Packages created.
It relies on Multicast
1. I don't know your LAN configuration, but if you're here I hope you know how to handle that
2. Right?

Intended public

I expect you to have some knowledge regarding: TCP, UDP, IP ranges, and Typescript (not only C/C++)

Let's start

Library

In your Arduino IDE install the Simple Repository IO

Changing the wiring from previous post

What	Amount
Arduino*	1
breadboard	1
220 ohm resistor	1
Led (built in)	1
Led	1

I hope you have a WeMos D1 R1 compatible Arduino board or an Wi-Fi module compatible with ESP8266WiFi and know how to wire it

Pin D10 to resistor
Resistor to LED
LED to GND

Code

I created a tag so you can use the same version I used for this article.

Hub >> arduino code files
1. It starts defining the components (see last article to better understanding)
2. Then it MULTICASTS a message via UDP. Something like "I live, again"
3. Wait for WiFi TCP messages with some command
Server >> typescript node server
1. It starts two servers
2. UDP server to add hubs to its list
3. TCP server to act as an API
  - each endpoint calls the Arduino

Results

When calling http://localhost:3000/Hub_A/write/led/true

When calling http://localhost:3000/Hub_A/write/led/false

When the pwm_led is set to 0 (zero) and calling http://localhost:3000/write/Hub_A/pwm_led/100

Previous step

Create an Arduino library to remote communication

Next step

Create a React Native app to handle the data

Arduino remotely controlled

Iago — Sat, 30 Sep 2023 14:11:39 +0000

Introduction

Hi all,

This is my first post here and I hope I write many more.

What are the problems I want to solve?

I want to create Arduino Hubs with actuators and sensors, but they must be controlled remotely.
This will ease my mind that wants to create something

What is the solution?

I created an Arduino library that can do the following:

You assign pin, names and some typing for each actuator/sensor
Every item is assigned to a CentralCommandUnit (CCU) that will handle everything from that point

What are the weak points?

It's in early stage
1. Sometimes I see a problem that must be fixed with breaking changes
Currently only works for bool and int values

Intended public

Please keep in mind that the code here, even for a 'blink' code, is more verbose than it would be in a beginner project. So it's not for those who are starting with Arduino. You won't see pinMode, analogRead... because the library handles that.

Let's start

Library

In your Arduino IDE install the Simple Repository IO

Some wiring

What	Amount
Arduino	1
Photo resistor	1
breadboard	1
220 ohm resistor	1
Led (built in)	1

Pin A0 connected to the resistor and photo resistor
The other resistor leg connected to GND
The other photo resistor leg connected to 5V

Let's use the built in led.

Code

// imports
#include "bool_component.h"
#include "ccu.h"
#include "command_factory.h"
#include "percent_component.h"
#include "Simple_Repository_IO.h"

// for this library, we must know only the names
const String led = "led";
const String photoSensor = "photo";
// this one is responsible to execute commands
CentralCommandUnit ccu;

void setup()
{
  // creating a new Repository with 2 items
  Repository *hub = new Repository("hub", 2);

  // LED_BUILTIN >> your IDE knows the builtin led for your Arduino board
  // BoolComponent >> this led will turn on or off. This seems to be a boolean for me :)
  // Component::IoType::OUT >> we are not reading values, we're showing them
  BoolComponent *bc = new BoolComponent(LED_BUILTIN, led, Component::IoType::OUT);
  // A0 >> analogic input pin
  // PercentComponent >> the value starts at 0 (zero - pitch dark) and goes to 100 ("praise the sun")
  // Component::IoType::IN >> we are reading values
  PercentComponent *pc = new PercentComponent(A0, photoSensor, Component::IoType::IN);

  // adding to the repository
  hub->put(0, bc);
  hub->put(1, pc);
  // starting the Central Command Unit
  ccu.setup(hub);

  Serial.begin(9600);

  // ccu.execute >> tells the ccu to do some command
  // CommandFactory::describe() >> this is to create a JSON from your Arduino hub stored into the repository
  String result = ccu.execute(CommandFactory::describe());
  Serial.println(result);
}

// Please, don't use this library as the example bellow
// This is an example to it running. In the next article, we'll send commands remotely
void loop()
{
  // CommandFactory::read(photoSensor) >> asking the current value for the component with the name stored into the variable
  String value = ccu.execute(CommandFactory::read(photoSensor));

  const bool isBright = value.toInt() > 50;

  // CommandFactory::write(led, !isBright) >> change the value of an 'output' component with that name
  ccu.execute(CommandFactory::write(led, !isBright));
  delay(100);
}

Results

Turn on the lights = led off
Turn off the lights (or cover the photo resistor) = led on

Yes, the code is VERY verbose. But this library is for remote control the Arduino.

Next steps

Connect the Arduino to a server
1. receive commands
2. return data
3. Create an API to get/set the hubs information
Create a React Native app to handle the data