In this project, we're going to connect two ESPs wirelessly and send data from three sensors to an Excel spreadsheet. This tutorial walks you through the process of installing a wireless weather station in your own home, complete with data logging capabilities.

Recommended: 2x ESP-12E Read More About the Best ESP8266 Wi-Fi Development Boards. Alternative: 2x ESP-201 + 1x FTDI Programmer 1x DS18B20 1x Breadboard 3x Pushbutton 3x 10k Ohm Resistor 1x 4700 Ohm One ten-thousand-ohm resistor Potentiometer

DS18B20 - One Wire Digital Temperature Sensor We will be measuring temperatures with a DS18B20 one-wire digital temperature sensor for the duration of this project. First, let's learn how to wire up our temperature sensor so that we can move on to the programming portion of this lesson. Because the DS18B20 can be powered by voltages ranging from 3.0V to 5.5V, you simply need to connect its GND pin to the ESP8266's GND pin, and its VDD pin needs to be connected to the ESP8266's 3.3V. After that, connect the DQ pin on the ESP8266 to the IO04 port. Pulling the DQ pin up to 3.3V requires the use of a pullup resistor with a value of 4K7 ohms. Reading ADC Value We are going to read an analog value using the ADC pin, and when people talk about the ADC pin on the ESP, you will frequently hear the following

different terms used interchangeably: ADC (Analog-to-digital Converter) TOUT Pin6 A0 Analog Pin 0 These are all different names for the same pin on the ESP8266, which will be discussed in more detail in the following section (read this article for more information on the ADC pin). When TOUT is connected to an external circuit, the input voltage range is 0 to 1.0 V, and the current precision of TOUT (Pin6) is 10 bits. Getting Access to the Analog Pin on the ESP8266, it is very simple to gain access to the ADC when using an ESP-201; all you need to do is connect a jumper wire to the pin that is highlighted in the figure below. Client Circuit If you want to build your own ESP client, follow this circuit, and if you are going to use an ESP-12, you can look at the schematics.

Simulating wind speed requires the use of the right switch, which is connected to IO05. The program does not currently provide a real-time wind speed reading; rather, it provides an average wind speed over the previous 5 seconds. Therefore, it makes no difference how quickly you press the right switch. If you press the right switch five times within the sampling period of five seconds... That translates into an average of once per second, which is 1.492 miles per hour (or 2.4 kilometers per hour). Since we are using the integer version of NodeMCU at the moment, you will get 1.492 miles per hour and 24 kilometers per hour. You will need to do some division in the spreadsheet by both 100 and 10, in that order. Final Server Circuit If you want to make your own ESP server, follow this circuit, and if you're going to use an ESP-12, you can look at the schematics.

We have designed a unique printed circuit board (PCB) for the ESP-201. This is what you need to know: yellow wire: can either connect GPIO 0 to GND to flash NodeMCU firmware or to VCC to save scripts to ESP. GPIO 15 is hard wired to GND Reset button and has a 10K Ohm pull-up resistor connected to the RST pin (in order to reset the board, the RST pin has to be pulled down and then has to go back up) Putting Everything Together Turn on both of your ESPs and check to see that the ESP server is still able to establish serial communication with your computer. This is necessary

because you will need to post the data to your Excel spreadsheet using this method. Downloading and Installing Things Gateway In order to write data on an Excel spreadsheet and display self-updating real- time charts, the team working on this project is going to use a piece of software developed by Roberto Valgolio called Things Gateway. Things Gateway is a program for personal computers that connects a microcontroller and gives it the ability to do the following things: Get data from Excel files Write Excel files Write CSV log files Send emails (when certain conditions are met) Please display the values and charts (charts are Excel independent) Things Additionally, Gateway can connect to a GPS and display the

Information on speed, heading, and altitude, as well as other navigational elements Tracks updated in real time on Google Maps Visit the website for Things Gateway, download the program, and then install it on your device. The Beta4 version of the software was used to test this project. Launching Your Things Gateway Application Getting the application for Things Gateway up and running is a very simple process. Open the application by navigating to Your Computer > Documents > ThingsGateway on your computer.

Navigate to the Configuration tab. Choose the Serial COM Port that is connected to your ESP8266 Server. Adjust the speed of the serial port to 9600.

Launch the RealTime tab, then select From Serial to Excel from the drop- down menu.

Your data should begin to populate an Excel spreadsheet that should have suddenly appeared on your computer screen every few seconds.

Your information is being saved in the sample spreadsheet created in Excel that is located in that folder. Future Improvements Throughout the course of this guide, we built a fundamental system that makes use of two ESP8266 microcontrollers and the Things Gateway application to transmit data wirelessly to an Excel spreadsheet. You'll be able to experiment with additional features offered by Things Gateway, such as the following when you use this example: Graph that automatically updates itself in real time (not Excel dependent) Data logging in .csv files Sending of an automatic email when predetermined conditions are satisfied (such as a wind speed greater than a certain number of kilometers per hour, a temperature lower than a certain value, etc.)

warning of problems with the heating system or the freezer not being sufficiently cold etc.) Logging of data in stream.txt, which can be replayed at speeds of 0.1, 0.5, 1, 5, 10, 60, or 3600 times faster than the original. Additionally, GPS tracks can be streamed on Google Maps at the actual speed or at 0.1, 0.5, 5, 10, 60, or 3600 times the normal speed.

Other sensors like bmp180 barometric pressure sensor Photosensitive cells Detector of humidity Any additional digital or analog sensor that employs multiplexing It is important to note that Things Gateway was developed for use with Arduino boards; however, as long as you send the appropriate string via serial, you can use it with any board you like.