Welcome to our Getting started guide on ESP-WROOM-02 board. We had already introduced this board in our previous guide Introduction to ESP8266, there we had mentioned about the ESP-WROOM-02 adapter board as well. Here in this blog, we are using ESP-WROOM-02 with Adapter board, since using the adapter board will give us the flexibility to build and test circuit on a breadboard. Let us have a look at the list of items we needed for getting started with ESP-WROOM-02.

Hardware Needed:

ESP-WROOM-02 Board	Breadboard	3.3V Voltage Regulator	1K Resistors
100uf Electrolytic Capacitor	7mm Tactile Switch	5V Power Adapter	10k Resistor
5mm LED	Mini USB Cable	USB to Serial Converter	Jumper Wires
3.3uf Electrolytic Capacitor	Breadboard Power Supply	Micro USB Pin Breakout Board	0.1uf Ceramic Capacitor

You do not need all the above mentioned hardware, some of them are optional, which we had mentioned in details in various sections below.

ESP-WROOM-02 Pinouts:

It is always important to understand the board which you are working with, is capable of what all stuffs, for this we had added a graphical pinouts and description below:

ESP-Wroom-02 Graphical Description

Circuit Schematics:

The ESP-WROOM-02 boards needs few external components to get it working, we had a schematics for ESP-WROOM-02 board below:

Circuit Schematics

Now, if you notice in the schematics, we had added pullup resistors on most of the communication lines, if you are not using those pins, you can ignore those resistors. But the resistors on following lines are must to get it working, i.e GPIO0, reset and enable.

Note: The power Supply schematics is not included in the above circuit.

The power supply to the circuit must be 3.3v and you can use any option to power the circuit, like using breadboard power supply(listed in the hardware needed section) and 9v battery or you can power the board directly from USB to serial converter, make sure that converter must be 3.3v logic ones and it is capable enough to supply minimum of 500mA. We tried to power the system from Sparkfun basic 3.3v FTDI converter but we had faced issue several times, if you are looking to power from converter only, we will recommend you to use the Sparkfun beefy FTDI board. We had used 5v Power Adapter and a 3.3V voltage regulator setup on breadboard to power the system, We had added the 3.3V voltage regulator Schematics below:

3.3V Voltage Regulator Schematics

The voltage Regulator Part is really Simple, if you seen the schematics, you can notice that, we used 4 capacitor in the circuit, Cout capacitor can be replaced with 3.3uF Capacitor or some other higher value than 10uF if you have. We supplied Vin from the 5v USB power Adapter (Refer the hardware needed section), we used the Micro USB Breakout Board (Refer the hardware needed section) to breakout the power lines from USB adapter, you can use your phone chargers as well,if you have these breakout board with you.

Make sure you use the proper pins of the voltage regulator while assembling your circuit. Refer the LD33V pinouts below:

LD33V Pinouts

Now, its time to assemble all this circuit into a breadboard, make sure you follow the connections, as shown, otherwise, your circuit might not work.

Assemble the Circuit on a Breadboard:

The first thing in the breadboarding is always begin with Power supply, if you are using breadboard Power Supply module (Refer the hardware needed section)  then you do not have to worry much, all you need is battery with DC Jack Male Connector or you might have power adapter with DC Male Jack on it, use it and you are ready to go. Refer the below diagram for using a breadboard power supply.

Breadboard Power Supply

But we are using Voltage regulator to build our own power supply and which we can use to fed power from standard micro USB power adapter/ Mobile Charger. Refer the Power Supply section below for better idea on this.

3.3V Breadbord Power Supply

Note: If you are using some other voltage regulator than what we mentioned, then make sure that you cross check the pinouts and connect accordingly. Refer the hardware needed section for the USB Breakout Board which you can use.

Once the power supply is done, now we will assemble the circuit for ESP-WROOM-02 Board as shown in the schematics above.

ESP-WROOM-02 Breadboard Arrangement

Now you are all done with connections, now its time to upload the code, now for this you need a USB to Serial Converter to establish a Serial communication between the WROOM board and the computer. We used the sparkfun basic ftdi board to made it work, you can use any 3.3V logic converter to do the serial communication, just make sure to make the proper connection with this WROOM board. For this we had added a simple graphical representation, where you need to make the connections, refer the image below:

ESP-WROOM-02 Serial Communication

As you can see that it is clearly labeled which connection will go where into this breadboard, all you need to do is connect jumper wires to your Serial Converter and connect it exactly at the same position, i.e RX,TX and GND , these three lines are required. There is no need to cross connect the RX TX line, since it is already been take care of while labeling, just connect straight away the converter TX pin to WROOM pin 11 and Converter RX pin to WROOM pin 12 and common ground is must between the circuits. Lets begin with programming the WROOM board.

Uploading first Program

Step 1: Put the WROOM Board in Program Download Mode:

Since you are ready with hardware, its time to put the WROOM board into UART Download mode,to do so, all you need to do is:

1. Press both the RESET button and PROGRAM Button together.
2. Leave the RESET button alone and keep Pressing the PROGRAM button for 1 more second.
3. Leave the PROGRAM Button, now you are in UART Download mode.

So every time, when you need to upload the code, you have to do this before uploading, this is because the “auto Program” is not implemented in the circuit we built. To do so you need to add some transistors and you need to make some more connections from the Serial Converter board, this feature is not covered in this tutorial. Refer the Reset and Program Switch in the above image.

Step 2: Set proper serial port and board in the Arduino

Once the board is in download mode. You need to Open the Arduino and install the ESP8266 Core for the Arduino, if you have this in Arduino, you can ignore this. If you don’t have any ESP8266 board present in you Arduino. You need to do the following :

http://arduino.esp8266.com/stable/package_esp8266com_index.json

Add the above mentioned line to Arduino: File -> Preferences -> Additional Board Managers URL

If there is an entry already, add the line by inserting a comma. If you need more instruction visit this github page.

Restart the Arduino after above step and open the boards manager from tools -> boards option and install the ESP8266 Core to the boards, after installation ,restart the Arduino again and you will see a set of ESP8266 boards as follows:

ESP8266 Boards

Now if you see we had selected the board option as ThaiEasyElec’s ESPino , we tried out other boards as well and we did not had any issue with other boards as well. The common setting for most of the board is to set the frequency to 80Mhz, you can overclock the board if needed. Flash Size if available set to 2M, else leave it to defualt option. The WROOM board comes with 2MB SPI Flash with four supported SPI modes: Standard SPI, DIO (Dual I/O), DOUT (Dual Output), QIO (Quad I/O) and QOUT (Quad Output).

Refer the latest WROOM Board Datasheet here

Once the Clock and Flash is set, select the proper serial port and you are ready to upload the code.

Step 3: Upload the first program

Since you are done with everything, lets begin uploading the first code. Refer the image below:

Example Program

Upload the following code from File -> Examples -> ESP8266 -> Blink

/*
 ESP8266 Blink by Simon Peter
 Blink the blue LED on the ESP-01 module
 This example code is in the public domain
 
 The blue LED on the ESP-01 module is connected to GPIO1 
 (which is also the TXD pin; so we cannot use Serial.print() at the same time)
 
 Note that this sketch uses LED_BUILTIN to find the pin with the internal LED
*/

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);     // Initialize the LED_BUILTIN pin as an output
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, LOW);   // Turn the LED on (Note that LOW is the voltage level
                                    // but actually the LED is on; this is because 
                                    // it is acive low on the ESP-01)
  delay(1000);                      // Wait for a second
  digitalWrite(LED_BUILTIN, HIGH);  // Turn the LED off by making the voltage HIGH
  delay(2000);                      // Wait for two seconds (to demonstrate the active low LED)
}

Note: Make Sure the converter is connected and board is in program Download Mode.

Once uploaded you can see that the LED connected in the GPIO Pin 16 will start blinking. The LED_BUILTIN is defined different to other boards but for ThaiEasyElec’s ESPino board, the LED_BUILTIN is set to GPIO 16, if you still feel doubtful we will recommend you to initialize pin numbers manually with pinMode(Pin_number, INPUT/OUTPUT);

Note: If you are not able to get any blinking, try the serial window debugging and if you are getting any WDT(Watchdog Timer) related issues, try changing the power supply, since the WROOM board needs a stable power supply.

Hope you enjoyed this getting started tutorial, now its your turn to build some cool IoT Projects with this cheap and tiny little board. Do let us know, what you build with this little beast. We are happy to help if you found yourself in some sort of trouble.

This quick guide will give you idea about ESP8266 and some boards based on it. The ESP8266 (presently ESP8266EX), it is a chip with which manufacturers are making wirelessly networkable micro-controller modules. More specifically, ESP8266 is a system-on-a-chip (SoC) with capabilities for 2.4 GHz Wi-Fi (802.11 b/g/n), general-purpose input/output, Inter-Integrated Circuit (I²C), analog-to-digital conversion (10-bit ADC), Serial Peripheral Interface (SPI), I²S interfaces with DMA (sharing pins with GPIO), UART and pulse-width modulation (PWM). It employs a 32-bit RISC CPU based on the Tensilica Xtensa LX106 running at 80 MHz (or overclocked to 160 MHz). It has a 64 KB boot ROM, 64 KB instruction RAM and 96 KB data RAM. External flash memory can be accessed through SPI.

The ESP8266 is an amazing chip for all your home automation & Internet of Things projects. This chip costs less and has WiFi connectivity and is compatible with the Arduino IDE.Various vendors have consequently created modules containing the ESP8266 chip at their cores. Some of these modules have specific identifiers, like “ESP-01” through “ESP-13”. ESP8266-based modules have demonstrated themselves as a capable, low-cost, networkable foundation for facilitating end-point IoT developments. Espressif’s official module is presently the ESP-WROOM-02. The AI-Thinker modules are labeled ESP-01 through ESP-13. NodeMCU boards extend upon the AI-Thinker modules. Olimex, Adafruit, Sparkfun, WeMos, ESPert (ESPresso) all make various modules as well. See this ESP8266 article for more information about popular ESP8266 modules. There are many choices available in the market, and it is easy to get lost between all of them. we do have a bunch of them in our store, check out our ESP8266 boards collection.

First, We would like to show you the basic ESP8266 module, i.e ESP-01

ESP-01 Module

ESP-01

This is the first module that came out on the market. It is the cheapest and nearly the smallest module available. It is perfectly usable with the Arduino IDE for example.However, it comes with serious disadvantages. First, you can’t plug it into a breadboard without an adapter or you need to use jumper wires. Then, you don’t have access to all the input/output pins of the ESP8266 chip, which is a problem if you have complex projects that you want to build. However, for simple projects, this is a good module to start with.

Have a look at the pinouts:

ESP-01 Pinouts

ESP-WROOM-02 Module

ESP-WROOM-02 is a low-power 32-bit MCU Wi-Fi module, based on the ESP8266 chip. TCP/IP network stacks, 10-bit ADC, and HSPI/UART/PWM/I2C/I2S interfaces are all embedded in this module.It uses a 2 MB SPI flash connected to HSPI, working as the SDIO/SPI slave with the SPI speed of up to 8 Mbps. This module can be easily integrated into space-limited devices, due to its small size of only 18mm x 20mm x 3mm.

ESP-WROOM-02

This official WROOM board is perfect option if you are planning to build something using ESP8266 Core. This module has most of the things built in, you just needs few external components to get it working. The Board comes in SMD package, thus saving the space on the mother board. Due to its tiny size its perfect for IoT applications. Following pins are accessible on the WROOM board:

ESP-WROOM-02 Pinouts

But it is very difficult to start using ESP-WROOM-02 PCB without any soldering, thus we are offering a presoldered ESP-WROOM-02 Adapter board in out store.Have a look at the adapter board below:

ESP-WROOM-02 with Adapter Baord

ESP-WROOM-02 Board with Adapter

This board is perfect to use with breadboard, you do not need any soldering, it will sit easily on the breadboard. This board will also give you the option to solder the board easily to proto boards, without any complication. The adapter board dimensions will be 25.5mm x 26mm.

We do have different types of ESP8266 boards from different manufacturers which uses ESP8266 as it core. The difference in these boards is that every manufacturer will add their own peripherals and their own standard pinouts, even some boards comes with onboard USB to Serial Converter, so it will be very easy to program those board. Have a look at the ESP8266 Boards we having with us.Below we had added the Summary table for ESP8266 modules, to get better idea and see the difference between them:

Hope things are more clear to you now, before we finish with this blog, have a look at variety of projects and tutorials based on the ESP8266 boards we had added in our blog.

The particle photon provides one of the best IoT experience in the market, its out of the box experience is unparalleled. Here we will be talking about the steps required to get started with the Particle Photon.

Hardware Required:

	Particle Photon w/ Headers
	microUSB Cable

Manually upgrading to the latest firmware:

The Particle Photon may not come with the latest firmware, the firmware is automatically upgraded to the latest version when a program is uploaded. Alternatively, the firmware can also be upgraded to the latest version using the Particle Firmware Manager app. You can get the latest version from Firmware Releases page

Once downloaded, run the application as administrator this will automatically install the drivers first and will later ask to connect the board.

Once the drivers are installed, connect the Particle Photon and click on Update to X.X.X where X.X.X is the firmware version.

Connecting the Particle Photon to the WiFi using the Particle App

1. The easiest way to configure the Particle Photon is using the Particle App, there are Android and iOS versions available.
2. Once the board is booted up and in setup mode the on board RGB Led will start blinking blue.
3. Click on setup a photon and choose the WiFi AP corresponding to Photon-XXXX where XXXX varies from board to board. Once connected select your WiFi and enter the password.
4. The tinker code helps you configure the various GPIO pins on the Photon through the mobile app. If the board is flashed with a non-Tinker code, it can be re-flashed though the app itself. The on-board LED is connected to D7

Programming the Particle Photon

Particle offers 3 options to program the Particle Photon.

• Online
• Semi-offline
• Offline

In this tutorial we will be covering the Online and the Semi-offline method

Programming the Particle Photon Online

Particle has a great online IDE that can be used for pushing code onto the Particle Photon.

	Flash the code on to the Particle Photon
	Verify the code of errors
	Save current code
	Show/Hide the side bar
	List of libraries
	View the docs
	List of devices
	Open the Particle Dashboard that will list all your devices and products
	Basics settings for Particle Account

Step 1: Get the Code ready

The first step would be to create an app, for the tutorial we will be using the blink an LED app. Once the code is typed out and ready to be flashed, the board that needs to be flashed needs to be selected.

Step 2: Select the device

The device to be flashed can be selected from the list of devices tab. Here you can also select the firmware that is to be used.

Step 3: Flashing the code

Flashing the code is as simple as clicking on the flash button. The first time uploading the code might take longer as the firmware will need be upgraded, this process is denoted by the magenta color on the RGB Led

Programming the Particle Photon using the IDE

The Particle IDE offers a local solution to coding on the Particle Photon, the IDE allows you to code locally but still requires an internet connection to be able to compile the code and to push it to the board.

In order to be able to select the board that needs to be programmed, the IDE needs access to your particle account. This can be done through the Particle menu, Particle → Login to Particle Cloud
The device can be selected from Particle → Select Device

In order to get started, we need to create a project folder which will hold the code. Once done add the project folder to the Particle IDE. This will show in the side bar

All of the files for the project will be shown in the sidebar. Any library that is to be included in the code must be added to this folder , all added libraries will show up under this.

Once the code is ready to be uploaded, click on flash. The status will display success once uploaded.

Want to check if you left your lights ON remotely, need to detect the zero crossing point for your dimming circuit or do you just need to interface a 230V signal to your Arduino? The AC Mains Detector board simplifies interfacing high voltage signals by giving a digital output when an AC voltage is detected. By disabling the on board capacitor, zero crossing detection is possible as well.

AC Line detection Module

You can buy this item from the following links:

Within GCC: Edwin Robotics

International Order: Tindie

Let us have a look at the guide contents, refer to the list below:

• Components

• Board Pinouts

• Circuit Schematics

• Interfacing with Arduino

• Zero Crossing detection using Arduino

Components

AC Line detection Module

Arduino UNO

Male-Female Jumper wires

Board Pinouts

Top Side

Bottom Side

• AC-IN – Connect the AC line that needs to be detected here.
• – (negative sign) – Connect to ground of microcontroller
• + (positive sign) – Connect to VCC of microcontroller in case external pull-up is required
• S – Connect to a digital/interrupt pin of microcontroller

Note: Working with AC voltages is DANGEROUS, care must be taken to prevent any short circuits or mistakes in connection. And as always, you are doing this project at your own risk and Edwin Robotics or the Author cannot be held liable for any damages.

Circuit Schematics

The circuit consists of two main parts, first is the Bridge Rectifier (DB107) which converts the AC signal to DC and the second is the Optocoupler (LTV816), which provides isolation between High voltage(HV) side and Low Voltage (LV) Side.

A pull-up resistor is provided for use with microcontrollers (e.g. ESP8266) that do not have an internal pullup resistor.

Interfacing with Arduino

The hardware connections are pretty straightforward. On the low voltage side the + (positive symbol) goes to VCC of microcontroller, – (negative symbol) goes to GND and S goes any digital/interrupt pin. On the high voltage side, the AC lines are connected.

Arduino Connections

In this example, Pin 2 on the arduino is used in this example as it can be used as an interrupt pin as well.

Sample Code:

#define Signal_Pin 2  // Modify this pin as per your connection

void setup() {
  pinMode(Signal_Pin , INPUT_PULLUP);
  Serial.begin(9600);
}

void loop() {
  if ( digitalRead(Signal_Pin) == 0 )
    Serial.println (" AC Mains 230v Detected ");
}

Note: Do not touch the PCB once powered, you can get electrocuted. Keep it away from reach of humans/Animals. Make sure that there are no shorted wires, when connecting the 230v AC mains supply.

Zero Crossing Detection using Arduino

By default zero crossing detection is disabled by the use of a 2.2uF capacitor, in order to use the board for zero crossing detection the capacitor needs to be bypassed by cutting the trace shown below. It can be resoldered at any time later to disable zero crossing:

Modify the jumper

The Arduino connection will be same as before, upload the following code and view the output on Serial Monitor at 9600 baud rate:

#define Signal_Pin 2 //Use Arduino Pin 2 or pin 3, both supports hardware interrupt
int counter=0;

void setup()
{
  pinMode(Signal_Pin , INPUT_PULLUP);
  Serial.begin(9600);
  attachInterrupt(0, zero_crosss_int, RISING);  // Choose the zero cross interrupt # from the table above
}

void zero_crosss_int()  // function to be fired at the zero crossing to dim the light
{
  counter++;
}

void loop()
{
  Serial.println(counter);
}

You can see that the counter value increases with every cycle of AC line and the moment you turn off the AC line, the counter Stops as well.

References:

• DB107 Rectifier Datasheet
• LTV-816 Datasheet