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Basics: Project 086a

Project name: ESP8266 ESP-12E module, BME280 sensor - Temperature, Pressure and Humidity

Tags: Arduino, Arduino IDE, ESP8266 ESP-12E module, ESP, ESP8266, WI FI module, ESP-12E, LoLin NODEMCU V3, NODEMCU, BME280, BME280 sensor, humidity, temperature, pressure, altitude, GY-BME280, Digital Sensor, SPI I2C Humidity Temperature and Barometric Pressure Sensor Module, GY-BME280-3.3

Attachments: I2Cscannersketch,bme280testsketch1,library1and library2

In this project, you needed these parts (Dear visitors. You can support our project buy clicking on the links of parts and buying them or donate us to keep this website alive. Thank you):

1.ESP8266 ESP-12E module with micro USB cable 1pc

2. Jumper cables F-M

3. Breadboard 1 pc

4. BME280 sensor module 1 pc

General

We will learn how to use ESP8266 ESP-12E module with BME280 sensor module. 

Understanding the ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3)

Understanding the BME280 module

The BME280 is the next-generation of sensors from Bosch, and is the upgrade to the BMP085/BMP180/BMP183 - with a low altitude noise of 0.25m and the same fast conversion time. 

The BME280 sensor module reads temperature, humidity, and pressure. You can also estimate altitude as the pressure changes with altitude. 

The sensor can communicate using either SPI (supports 3-, 4-wire SPI) or I2C communication protocols (there are modules of this sensor that just communicate with I2C, these just come with four pins).

The sensor comes with an on-board LM6206 3.3V regulator and I2C Voltage Level Translator, so you can use it with a 3.3V or 5V logic microcontroller like Arduino without worry.

The BME280 consumes less than 1mA during measurements and only 5μA during idle. This low power consumption allow the implementation in battery driven devices such as handsets, GPS modules or watches.

Specifications:

• Supply Voltage: 1.8 - 5V DC
• Interface: I2C (up to 3.4MHz), SPI (up to 10 MHz)
• Operational Range: Temperature: -40 to +85° C
• Humidity: 0-100%
• Pressure: 300-1100 hPa
• Resolution:Temperature: 0.01°C Humidity: 0.008% Pressure: 0.18Pa
• Accuracy:Temperature: +-1°C Humidity: +-3% Pressure: +-1Pa
• I2C address SDO LOW : 0x76 SDO HIGH: 0x77 

The module features a simple two-wire I2C interface which can be easily interfaced with any microcontroller of your choice. The default I2C address of the BME280 module is 0x76 and can be changed to 0x77 easily with the solder jumper besides chip.

How to change I2C Address?

1. Locate the solder jumper besides chip. By default the middle copper pad is connected to the left pad.
2. Scratch the connection between the middle and the left copper pad to disconnect those using a sharp knife.
3. Add a solder blob between the middle and the right copper pad to join them. It allows you to set the I2C address 0x77.

TX - transmit pin. GPIO pin

RX  - receive pin.  GPIO pin

3V3 (or 3V or 3.3V) - power supply pin (3-3.6V). 

GND ( or G) - ground pin.

RST - reset pin. Keep it on high (3.3V) for normal operation. Put it on 0V to reset the chip.

EN - Chip enable. Keep it on high (3.3V) for normal operation.

Vin - External power supply 5VDC.

D0-D8 - GPIO (General Purpose Input Output) pins 

D5-D8 - SPI interface

D1-D2– I²C/TWI Interface

SC (or CMD) - (Chip Select) - the pin that the master can use to enable and disable specific devices. GPIO pin

SO (or SDO) - Master In Slave Out (MISO) - SPI communication. The Slave line for sending data to the master. GPIO pin

SK (or CLK) - SCK (Serial Clock) - SPI communication.The clock pulses which synchronize data transmission generated by the master. GPIO pin

S1 (or SD1) - Master Out/Slave In (MOSI). SPI communication. The Master line for sending data to the peripherals. GPIO pin

S2 (or SD2) - GPIO pin

S3 (or SD3) - GPIO pin

VU (or VUSB) - external power 5VDC.

A0 - ADC output.

RSV - reserved

Wiring

BME280 sensor  Nodemcu 1.0

GND                 G (GND)

VIN                  3V3

SCL                  D1 (GPIO 5)

SDA                 D2 (GPIO 4)

Step by Step instruction

1. Adding ESP8266 platform to Arduino IDE

The Arduino environment has to be set up to make it compatible with the ESP8266 ESP-12E module. We are using PC with Windows 7 64 bit OS.

1. Download and install the Arduino IDE. You can download it here 
2. Open Arduino IDE. 
3. Open the Preferences window from the Arduino IDE. Go to File -> Preferences.
4. 
5. Enter http://arduino.esp8266.com/stable/package_esp8266com_index.json into Additional Board Manager URLs field and click the “OK” button. If you already have a URL in there, and want to keep it, you can separate multiple URLs by placing a comma between them. (Arduino 1.6.5 added an expanded text box, separate links in here by line.)
6. 
7. Open Boards manager. Go to Tools -> Board -> Boards Manager…
8. 
   
9. There should be a couple new entries in addition to the standard Arduino boards. Look for esp8266. or scroll down to the ESP8266 entry (usually at the bottom). Select the ESP8266 entry. When you click it an install option will appear. Select the latest version and click install. 
10. 
11. The board definitions and tools for the ESP8266 include a whole new set of gcc, g++, and other reasonably large, compiled binaries, so it may take a few minutes to download and install (the archived file is ~110MB). Once the installation has completed, an Arduino-blue “INSTALLED” will appear next to the entry.
12. 
13. 

2. Uploading sketch to ESP8266 ESP-12E development board

If you’re using an ESP-12E NodeMCU Kit, uploading the sketch is very simple, since it has built-in programmer. 

Before use ESP8266 ESP-12E WI FI module (LoLin NODEMCU V3), you need to download the manufacture's driver (CH340)  for this chip and install it in your PC. Here is the link. See the description of driver installation package below: CH340 / CH341 USB to serial WINDOWS driver installation package that supports 32/64 bit Windows 10 / 8.1 / 8/7 / VISTA / XP, SERVER 2016/2012/2008/2003, 2000 / ME / 98, through Microsoft digital signature authentication, support USB to 3-wire and 9-wire serial port, with the product release To the end user. Applicable scope: CH340G, CH340C, CH340B, CH340E, CH340T, CH340R, CH341A, CH341T, CH341H chips.

If you have CP2102 chip then  you need to download the manufacture's driver for this chip and install it in your PC. Driver for Mac, Windows, Linux or more.. 

1. Do wiring.
2. Open Arduino IDE.
3. Plug your ESP8266 ESP-12E module into your PC USB port.
4. Choose your NodeMCU board. Go to Tools -> Board -> NodeMCU 1.0 (ESP-12E Module)
5. Select the correct com port.
6. 
7. Find your BME280 I2C address. Each device has an I2C address that it uses to accept commands or send messages. Compile and upload the I2Cscannersketch to your ESP8266 ESP-12E module.
8. Open the Serial Monitor at a baud rate of 115200. Arduino will scan the address range looking for a reply.  Even though the documentation said it was 0x77, this scanner can detect different (in our case 0x76). Adafruit_BME280 library has default I2C address 0x77 and if you are getting 0x76 you need to modify line of code in  bme280testsketch1: status = bme.begin(); to status = bme.begin(0x76);
9. 
   
10. Modify, compile and upload bme280testsketch1 to your ESP8266 ESP-12E module. 
11. Open Serial monitor at 115200 baud. You can see the temperature, pressure and humidity from your BME280 sensor module now.
12. 
13. 

Code

The sketch starts with including four libraries viz. Wire.h, SPI.h, Adafruit_Sensor.h and Adafruit_BME280.h.

Next, we define SEALEVELPRESSURE_HPA variable needed to calculate the altitude and create an object of Adafruit_BME280 library so that we can access functions related to it.

In setup section of code we initialize the serial communication with PC and call the begin() function.

The begin (I2C_ADDR) function takes the I2C address of the module as parameter. If your module has different I2C address or you changed it, you need to specify it correctly. This function initializes I2C interface with given I2C Address and checks if the chip ID is correct. It then resets the chip using soft-reset & waits for the sensor for calibration after wake-up.

In looping section of the code, we use following functions to read temperature, relative humidity & barometric pressure from the BME280 module.

readTemperature() function returns the temperature from the sensor.

readPressure() function returns the barometric pressure from the sensor.

readAltitude(SEALEVELPRESSURE_HPA) function calculates the altitude (in meters) from the specified atmospheric pressure (in hPa), and sea-level pressure (in hPa).

readHumidity() function returns the relative humidity from the sensor.

Summary

We have learnt how to use ESP8266 ESP-12E module with BME280 sensor module.

Libraries

• All libraries attached on the begining of this project description.
• Wire library included in your Arduino IDE.
• Adafruit BME280 library included. Download, unzip  and add to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC. You can read more about it here.
• Adafruit_Sensor library included. Download, unzip  and add to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC. You can read more about it here.

Sketch

• See on the begining of this project