ESP8266 and GY-21P module example

This module  combines a BMP280 sensor and an SI7021 sensor. The on-board BMP280+SI7021 sensor measures atmospheric pressure from 30kPa to 110kPa as well as relative humidity and temperature.

BMP280
Pressure range: 300-1100 hPa (9000 meters above sea level at -500m)
Relative accuracy (at 950 – 1050 hPa at 25 ° C): ± 0.12 hPa, equiv. to ± 1 m
Absolute accuracy (at (950 – 1050 hPa, 0 – +40 ° C): ± 0.12 hPa, equiv. To ± 1 m
Mains voltage: 1.8V – 3.6V
Power consumption: 2.7µA at 1Hz readout rate
Temperature range: -40 to + 85 ° C

SI7021
HVAC/R
Thermostats/humidistats
Respiratory therapy
White goods
Indoor weather stations
Micro-environments/data centers
Automotive climate control and defogging
Asset and goods tracking
Mobile phones and tablets
Size: 1.3*1cm/0.51*0.39″

Features:

Operation Voltage: 3.3V
I2C & SPI Communications Interface
Temp Range: -40C to 85C
Humidity Range: 0 – 100% RH, =-3% from 20-80%
Pressure Range: 30,000Pa to 110,000Pa, relative accuracy of 12Pa, absolute accuracy of 100Pa
Altitude Range: 0 to 30,000 ft (9.2 km), relative accuracy of 3.3 ft (1 m) at sea level, 6.6 (2 m) at 30,000 ft.

 

Layout

wemos and gy21b

wemos and gy21b

 

Code

I used a variety of Adafruit libraries for this example, I took the default examples and made the following out of them

https://github.com/adafruit/Adafruit_Sensor

https://github.com/adafruit/Adafruit_BMP280_Library

https://github.com/adafruit/Adafruit_Si7021

 

 

include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP280.h>
#include "Adafruit_Si7021.h"
 
Adafruit_BMP280 bme; // I2C
Adafruit_Si7021 sensor = Adafruit_Si7021();
 
void setup() 
{
Serial.begin(9600);
Serial.println("BMP280 and SI7021 (GY-21p) test");
 
if (!bme.begin()) 
{ 
Serial.println("Could not find a valid BMP280 sensor, check wiring!");
while (1);
}
 
if (!sensor.begin()) 
{
Serial.println("Did not find Si7021 sensor!");
while (true);
}
}
 
void loop() 
{
Serial.println("BMP280 results");
Serial.print("Temperature = ");
Serial.print(bme.readTemperature());
Serial.println(" *C");
Serial.print("Pressure = ");
Serial.print(bme.readPressure());
Serial.println(" Pa");
Serial.print("Approx altitude = ");
Serial.print(bme.readAltitude(1013.25)); // this should be adjusted to your local forcase
Serial.println(" m");
Serial.println();
 
Serial.println("SI7021 results");
Serial.print("Humidity: "); 
Serial.println(sensor.readHumidity(), 2);
Serial.print("Temperature: "); 
Serial.println(sensor.readTemperature(), 2);
Serial.println();
delay(2000);
}

 

Output

Open the serial monitor and you should see something like this

BMP280 results
Temperature = 27.26 *C
Pressure = 99042.63 Pa
Approx altitude = 191.78 m

SI7021 results
Humidity: 31.04
Temperature: 27.30

BMP280 results
Temperature = 28.43 *C
Pressure = 99044.82 Pa
Approx altitude = 191.60 m

SI7021 results
Humidity: 32.59
Temperature: 28.56

BMP280 results
Temperature = 28.17 *C
Pressure = 99037.41 Pa
Approx altitude = 192.22 m

SI7021 results
Humidity: 32.88
Temperature: 28.46

You can see the temperature output is close between the sensors

 

Links

Atmospheric Humidity Temperature Sensor Breakout Barometric Pressure BMP280 SI7021 for Arduino

ESP8266 and LSM6DS3 accelerometer and gyroscope example

The LSM6DS3 is a system-in-package featuring a 3D digital accelerometer and a 3D digital gyroscope performing at 1.25 mA (up to 1.6 kHz ODR) in high-performance mode and enabling always-on low-power features for an optimal motion experience for the consumer.

The LSM6DS3 supports main OS requirements, offering real, virtual and batch sensors with 8 kbyte for dynamic data batching.

ST’s family of MEMS sensor modules leverages the robust and mature manufacturing processes already used for the production of micromachined accelerometers and gyroscopes.

The various sensing elements are manufactured using specialized micromachining processes, while the IC interfaces are developed using CMOS technology that allows the design of a dedicated circuit which is trimmed to better match the characteristics of the sensing element.

The LSM6DS3 has a full-scale acceleration range of ±2/±4/±8/±16 g and an angular rate range of ±125/±250/±500/±1000/±2000 dps.

High robustness to mechanical shock makes the LSM6DS3 the preferred choice of system designers for the creation and manufacturing of reliable products.

The LSM6DS3 is available in a plastic land grid array (LGA) package.

Key Features

Power consumption: 0.9 mA in combo normal mode and 1.25 mA in combo high-performance mode up to 1.6 kHz.
“Always-on” experience with low power consumption for both accelerometer and gyroscope
Smart FIFO up to 8 kbyte based on features set
Compliant with Android K and L
Hard, soft ironing for external magnetic sensor corrections
±2/±4/±8/±16 g full scale
±125/±250/±500/±1000/±2000 dps full scale
Analog supply voltage: 1.71 V to 3.6 V
Independent IOs supply (1.62 V)
Compact footprint, 2.5 mm x 3 mm x 0.83 mm
SPI/I2 C serial interface with main processor data synchronization feature

 

Layout

Another easy device to connect

wemos and LSM6DS3

wemos and LSM6DS3

 

Code

I used the sparkfun library –https://github.com/sparkfun/SparkFun_LSM6DS3_Arduino_Library

This is the minimal example, there are many others

 

#include "SparkFunLSM6DS3.h"
#include "Wire.h"
#include "SPI.h"
 
LSM6DS3 myIMU; //Default constructor is I2C, addr 0x6B
 
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
delay(1000); //relax...
Serial.println("Processor came out of reset.\n");
 
//Call .begin() to configure the IMU
myIMU.begin();
 
}
 
 
void loop()
{
//Get all parameters
Serial.print("\nAccelerometer:\n");
Serial.print(" X = ");
Serial.println(myIMU.readFloatAccelX(), 4);
Serial.print(" Y = ");
Serial.println(myIMU.readFloatAccelY(), 4);
Serial.print(" Z = ");
Serial.println(myIMU.readFloatAccelZ(), 4);
 
Serial.print("\nGyroscope:\n");
Serial.print(" X = ");
Serial.println(myIMU.readFloatGyroX(), 4);
Serial.print(" Y = ");
Serial.println(myIMU.readFloatGyroY(), 4);
Serial.print(" Z = ");
Serial.println(myIMU.readFloatGyroZ(), 4);
 
Serial.print("\nThermometer:\n");
Serial.print(" Degrees C = ");
Serial.println(myIMU.readTempC(), 4);
Serial.print(" Degrees F = ");
Serial.println(myIMU.readTempF(), 4);
 
delay(1000);
}

 

 

Output

Open the serial monitor

Accelerometer:
X = -6.5480
Y = 2.1936
Z = -4.5135

Gyroscope:
X = 0.2800
Y = 0.0000
Z = 125.4400

Thermometer:
Degrees C = 25.0000
Degrees F = 77.0000

 

Link

1.71 V to 5 V LSM6DS3 SPI/I2C 3 Axis Accelerometer 3 Axis Gyroscope 6 Axis Inertial Breakout Board Embedded temperature sensor

Wemos and LIS2DH three-axis linear accelerometer example

The LIS2DH is an ultra low-power high performance three-axis linear accelerometer belonging to the “femto” family, with digital I2C/SPI serial interface standard output.

The LIS2DH has dynamically user selectable full scales of ±2g/±4g/±8g/±16g and it is capable of measuring accelerations with output data rates from 1 Hz to 5.3 kHz.

The self-test capability allows the user to check the functioning of the sensor in the final application.

The device may be configured to generate interrupt signals by two independent inertial wake-up/free-fall events as well as by the position of the device itself.

The LIS2DH is available in small thin plastic land grid array package (LGA) and is guaranteed to operate over an extended temperature range from -40 °C to +85 °C.

 

 

Key Features

Wide supply voltage, 1.71 V to 3.6 V
Independent IOs supply (1.8 V) and supply voltage compatible
Ultra low-power mode consumptiondown to 2 µA
±2g/±4g/±8g/±16g dynamically selectable full-scale
I2 C/SPI digital output interface
2 independent programmable interrupt generators for free-fall and motion detection
6D/4D orientation detection
“Sleep to wake” and “return to sleep” function
Freefall detection
Motion detection
Embedded temperature sensor
Embedded FIFO

Here is a schematic of the module

 

Connection

 

LIS2DH Wemos
VCC 3V3
GND GND
SDA D2(SDA)
SCL D1(SCL)

 

Code

This uses https://github.com/DFRobot/DFRobot_LIS2DH12/archive/master.zip , I had to change the I2C address for my board

I had to change the I2C address in the library, the default is 0x18 – the file was DFRobot_LIS2DH12.cpp

uint8_t DFRobot_LIS2DH12::sensorAddress = 0x19; /

 

#include <Wire.h>
#include <DFRobot_LIS2DH12.h>
 
 
DFRobot_LIS2DH12 LIS; //Accelerometer
 
void setup(){
Wire.begin();
Serial.begin(115200);
while(!Serial);
delay(100);
 
// Set measurement range
// Ga: LIS2DH12_RANGE_2GA
// Ga: LIS2DH12_RANGE_4GA
// Ga: LIS2DH12_RANGE_8GA
// Ga: LIS2DH12_RANGE_16GA
while(LIS.init(LIS2DH12_RANGE_16GA) == -1){ //Equipment connection exception or I2C address error
Serial.println("No I2C devices found");
delay(1000);
}
}
 
void loop(){
acceleration();
}
 
/*!
* @brief Print the position result.
*/
void acceleration(void)
{
int16_t x, y, z;
 
delay(100);
LIS.readXYZ(x, y, z);
LIS.mgScale(x, y, z);
Serial.print("Acceleration x: "); //print acceleration
Serial.print(x);
Serial.print(" mg \ty: ");
Serial.print(y);
Serial.print(" mg \tz: ");
Serial.print(z);
Serial.println(" mg");
}

 

 

Output

Open the serial monitor

Acceleration x: 0 mg y: -250 mg z: -375 mg
Acceleration x: 0 mg y: -625 mg z: -375 mg
Acceleration x: -125 mg y: -375 mg z: -500 mg
Acceleration x: -125 mg y: -500 mg z: -375 mg
Acceleration x: -125 mg y: -500 mg z: -375 mg
Acceleration x: 125 mg y: -375 mg z: -375 mg
Acceleration x: 0 mg y: -625 mg z: -375 mg
Acceleration x: 0 mg y: -375 mg z: -625 mg
Acceleration x: 0 mg y: -625 mg z: -375 mg
Acceleration x: -125 mg y: -500 mg z: -500 mg

 

Link

http://www.st.com/resource/en/datasheet/lis2dh.pdf

Wemos and TEMT6000 light sensor

TEMT6000X01 ambient light sensor is a silicon NPN epitaxial planar phototransistor in a miniature transparent 1206 package for surface mounting. It is sensitive to visible light much like the human eye and has peak sensitivity at 570 nm.

Here is a picture of a module

 

Here is a schematic of the module, basically the sensor acts like a transistor the greater the light present, the higher the analog voltage on the signal pin. So easy to read this with a Wemos Mini

APPLICATIONS

Ambient light sensor for control of display backlight dimming in LCD displays and keypad backlighting of mobile devices and in industrial on/off-lighting operation.

• Automotive sensors
• Mobile phones
• Notebook computers
• PDA’s
• Cameras
• Dashboards

 

Connection

 

 

Code

This is very basic, you would need to have some sort of value that you would try and detect, either too dark or light

#define LIGHTSENSORPIN A0 //Ambient light sensor reading
void setup()
{
pinMode(LIGHTSENSORPIN, INPUT);
Serial.begin(9600);
}
void loop()
{
float reading = analogRead(LIGHTSENSORPIN); //Read light level
Serial.println(reading);
delay(1000);
}

 

Output

Open the serial monitor and you should see something like this depending on how muck light is shining on the sensor

39.00
41.00
42.00
43.00
412.00
1024.00
1024.00
1024.00
1024.00
189.00
402.00
388.00

 

Links

TEMT6000 Light Sensor

https://www.vishay.com/docs/81579/temt6000.pdf