Category:

Espruino

Espruino and BMP280 example

by shedboy71 7th July 2017

written by shedboy71

BMP280 is an absolute barometric pressure sensor especially designed for mobile applications. The sensor module is housed in an extremely compact package. Its small dimensions and its low power consumption allow for the implementation in battery powered devices such as mobile phones, GPS modules or watches.
As its predecessor BMP180, BMP280 is based on Bosch’s proven Piezo-resistive pressure sensor technology featuring high accuracy and linearity as well as long term stability and high EMC robustness. Numerous device operation options offer highest flexibility to optimize the device regarding power consumption, resolution and filter performance. A tested set of default settings for example use case is provided to the developer in order to make design-in as easy as possible.

Applications
– Enhancement of GPS navigation (e.g. time-tofirst-fix improvement, dead-reckoning, slope detection)
– Indoor navigation (floor detection, elevator detection)
– Outdoor navigation, leisure and sports applications
– Weather forecast
– Health care applications (e.g. spirometry)
– Vertical velocity indication (e.g. rise/sink speed)
Schematics

Code

[codesyntax lang=”javascript”]

I2C1.setup({scl:B6,sda:B7});
var bme = require("BME280").connect(I2C1);

bme.readRawData();

var temp_cal = bme.calibration_T(bme.temp_raw);
var press_cal = bme.calibration_P(bme.pres_raw);
var temp_act = temp_cal / 100.0;
var press_act = press_cal / 100.0;

console.log("Pressure: " + press_act + " hPa");
console.log("Temperature: " + temp_act + " C");

[/codesyntax]

Output

Pressure: 1016.73902477584 hPa
Temperature: 25.34128807298 C

Links

https://www.espruino.com/BMP280

1PCS BME280 Digital Sensor Temperature Humidity Barometric Pressure Sensor

7th July 2017 0 comment

Espruino

Espruino and TCS34725 example

by shedboy71 6th July 2017

written by shedboy71

The TCS3472 device provides a digital return of red, green, blue (RGB), and clear light sensing values. An IR blocking filter, integrated on-chip and localized to the color sensing photodiodes, minimizes the IR spectral component of the incoming light and allows color measurements to be made accurately.

The high sensitivity, wide dynamic range, and IR blocking filter make the TCS3472 an ideal color sensor solution for use under varying lighting conditions and through attenuating materials. This data is transferred via an I2C to the host.

Schematics and connection

Code

[codesyntax lang=”javascript”]

I2C1.setup({scl:B6, sda:B7});
var tcs=require("TCS3472x").connect(I2C1, 1 /*integration cycles*/, 1 /*gain*/);

var v = tcs.getValue();

var v = tcs.getValue();
var min = Math.min(v.red, v.green, v.blue);
var range = Math.max(v.red, v.green, v.blue) - min;
var rgb = [ // values between 0 and 255
(v.red - min)*255/range,
(v.green - min)*255/range,
(v.blue - min)*255/range,
];

console.log("red " + v.red + " green " + v.green + " blue " + v.blue);
console.log("rgb = " +rgb);

[/codesyntax]
Output

>red 1024 green 768 blue 512
rgb = 255,127.5,0
Links
https://learn.adafruit.com/adafruit-color-sensors?view=all
http://ams.com/eng/Products/Light-Sensors/Color-Sensors/TCS34725
CJMCU-34725 TCS34725 Color Sensor RGB color sensor development board module

6th July 2017 0 comment

Espruino

Espruino and BMP180 example

by shedboy71 5th July 2017

written by shedboy71

The BMP180 is the new digital barometric pressure sensor of Bosch Sensortec, with a very high performance, which enables applications in advanced mobile devices, such as smartphones, tablet PCs and sports devices. It follows the BMP085 and brings many improvements, like the smaller size and the expansion of digital interfaces.
The ultra-low power consumption down to 3 μA makes the BMP180 the leader in power saving for your mobile devices. BMP180 is also distinguished by its very stable behavior (performance) with regard to the independency of the supply voltage.

Applications
– Indoor navigation
– GPS-enhancement for dead-reckoning, slope detection, etc.
– Sport devices, e.g. altitude profile
– Weather forecast
– Vertical velocity indication (rise/sink speed)

Schematic and Connection

Code

[codesyntax lang=”javascript”]

I2C1.setup({scl:B6,sda:B7});
var bmp = require("BMP085").connect(I2C1);

setInterval(function() {
bmp.getPressure(function(d) {
console.log("Pressure: " + d.pressure + " Pa");
console.log("Temperature: " + d.temperature + " C");
});
}, 1000);

[/codesyntax]

Output
Temperature: 22.925 C
Pressure: 101658 Pa
Temperature: 23.3 C
Pressure: 101668 Pa
Temperature: 26.09375 C
Pressure: 101680 Pa
Temperature: 27.93125 C
Pressure: 101680 Pa
Temperature: 29.0375 C
Pressure: 101674 Pa
Temperature: 29.81875 C
Pressure: 101672 Pa
Temperature: 30.15625 C
Pressure: 101680 Pa
Temperature: 29.7875 C
Links

https://www.espruino.com/BMP085

gy-68 Digital Barometric Pressure Sensor Board Module Replace BMP085 BMP180

5th July 2017 0 comment

Espruino

Espruino and HMC5883l example

by shedboy71 5th July 2017

written by shedboy71

The Honeywell HMC5883 is a surface mount multi-chip module designed for low field magnetic sensing with a digital interface for applications such as low cost compassing and magnetometry. The HMC5883 includes our state of the art, high-resolution HMC118X series magneto-resistive sensors plus Honeywell developed ASIC containing amplification, automatic degaussing strap drivers, offset cancellation, 12-bit ADC that enables 1° to 2° compass heading accuracy.
The I2C serial bus allows for easy interface

FEATURES

 12-Bit ADC Coupled with Low Noise AMR Sensors Achieves 5 milli-Gauss Resolution in ±8 Gauss Fields
 Built-In Self Test 
 Low Voltage Operations (1.6 to 3.3V)
 I2C Digital Interface
 Lead Free Package Construction
 Wide Magnetic Field Range (+/-8 Oe)
 Fast 116 Hz Maximum Output Rate

Schematic and Connection

Code

[codesyntax lang=”javascript”]

I2C1.setup( { scl: B6, sda: B7 } );
var compass=require("HMC5883").connect(I2C1,C11,0);

compass.setGain(1);
compass.setup(0,0);

compass.reads(function(a) {console.log(a);});

[/codesyntax]
Output
{ “x”: 43.24000078439, “y”: -125.12000226974, “z”: -164.68000298738, “overflow”: false }
{ “x”: 46.92000085115, “y”: -124.20000225305, “z”: -162.84000295400, “overflow”: false }
{ “x”: 15.64000028371, “y”: 111.32000201940, “z”: -234.60000425577, “overflow”: false }
Links

https://www.espruino.com/HMC5883

HMC5883L Triple Axis Compass Magnetometer Sensor Module 3V-5V For Arduino GY-273

5th July 2017 0 comment

Espruino

Espruino and BH1750 light sensor example

by shedboy71 4th July 2017

written by shedboy71

BH1750FVI is an digital Ambient Light Sensor IC for I2C bus interface. This IC is the most suitable to obtain the ambient light data for adjusting LCD and Keypad backlight power of Mobile phone. It is possible to detect wide range at High resolution.( 1 – 65535 lx ).

Features
1) I2C bus Interface ( f / s Mode Support )
2) Spectral responsibility is approximately human eye response
3) Illuminance to Digital Converter
4) Wide range and High resolution. ( 1 – 65535 lx )
5) Low Current by power down function
6) 50Hz / 60Hz Light noise reject-function
7) 1.8V Logic input interface
8) No need any external parts
9) Light source dependency is little. ( ex. Incandescent Lamp. Fluorescent Lamp. Halogen Lamp. White LED. Sun Light )
10) It is possible to select 2 type of I2C slave-address.
11) Adjustable measurement result for influence of optical window
( It is possible to detect min. 0.11 lx, max. 100000 lx by using this function. )
12) Small measurement variation (+/- 20%)
13) The influence of infrared is very small.

Schematics

Code

[codesyntax lang=”javascript”]

I2C1.setup( { scl: B6, sda: B7 } );
var bh=require("BH1750").connect(I2C1);

bh.start(1,0);
console.log("lux= " + bh.read());

[/codesyntax]

Output
>lux= 110
>lux= 0
>lux= 67.5
Links

https://www.espruino.com/BH1750
http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf

4th July 2017 0 comment

Espruino

Espruino and ADXL335 accelerometer example

by shedboy71 4th July 2017

written by shedboy71

The ADXL335 is a small, thin, low power, complete 3-axis accelerometer with signal conditioned voltage outputs. The product measures acceleration with a minimum full-scale range of ±3 g. It can measure the static acceleration of gravity in tiltsensing applications, as well as dynamic acceleration resulting from motion, shock, or vibration.

The user selects the bandwidth of the accelerometer using the CX, CY, and CZ capacitors at the XOUT, YOUT, and ZOUT pins. Bandwidths can be selected to suit the application, with a range of 0.5 Hz to 1600 Hz for X and Y axes, and a range of 0.5 Hz to 550 Hz for the Z axis.

Here is a typical module that makes it easy to work with the ADXL335

Features:

Name: ADXL335 module (triaxial accelerometer analog output)
Model: GY-61
Power supply :3-5v
Analog X, Y, Z three-axis output

Schematic

The following layout shows how to wire the ADXL335 module up to an Espruino

espruino and ADXL335

Code

This is code from the default example, I used the Espruino Web IDE

[codesyntax lang=”javascript”]

 var foo = require("ADXL335").connect(C3,A0,A1);
  setInterval(function() {
    var d= foo.readG();
    console.log("x " + d[0] + " y " + d[1] + " z " + d[2]);
  }, 1000);

[/codesyntax]

Output

x 0.46150911726 y -0.37102311741 z -0.69085221637
x 0.46883344777 y -0.36858167391 z -0.69573510337
x 0.46395056076 y -0.37346456092 z -0.69573510337
x 1.56015869382 y -0.13664454108 z 0.74959945067
x 0.63973449301 y 0.53963530937 z -0.20744640268
x 0.15388723582 y 0.06599526970 z 0.06599526970
x 0.62264438849 y -0.29533836881 z 0.57869840543
x 1.08896009765 y -0.53704127565 z 0.02204928664
x 0.23201342793 y -0.39543755245 z 0.56160830090
Links
http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL335.pdf

The sensor costs under $2

GY-61 ADXL335 Module Triaxial Acceleration Gravity Angle Sensor

4th July 2017 0 comment

Espruino

Espruino and ADS1015 12 bit adc

by shedboy71 15th October 2016

written by shedboy71

The ADS1015 is a precision analog-to-digital converters (ADCs) with 12 bits of resolution offered in an ultra-small, leadless QFN-10 package or an MSOP-10 package. The ADS1015 are designed with precision, power, and ease of implementation in mind. The ADS1015 features an onboard reference and oscillator. Data are transferred via an I²C-compatible serial interface; four I²C slave addresses can be selected. The ADS1015 operate from a single power supply ranging from 2.0V to 5.5V.

The ADS1015-Q1 device can perform conversions at rates up to 3300 samples per second (SPS). An onboard PGA is available that offers input ranges from the supply to as low as ±256 mV, allowing both large and small signals to be measured with high resolution. The ADS1015-Q1 device also features an input multiplexer (MUX) that provides two differential or four single-ended inputs.

The ADS1015-Q1 device operates either in continuous conversion mode or a single-shot mode that automatically powers down after a conversion and greatly reduces current consumption during idle periods

ads1015

Schematics

This example shows how to connect the module to an Espruino, we also added a potentiometer which can be used to test.

espruino-and-ads1015_bb

Code

This is the basic example from the Espruino web site, modified to keep looping and display the value

If you wanted to use ADC channel 1 to 3 you need to change the following

ads.getADC(0, function(val)

[codesyntax lang=”javascript”]

require("ADS1X15");

I2C1.setup({scl:B6,sda:B7});
var ads = require("ADS1X15").connect(I2C1);

ads.setGain(256); // +/- 0.256mV

setInterval(function() {
ads.getADC(0, function(val) {
  console.log("Read ADC value: "+val);
});
}, 1000);

[/codesyntax]

Links

1pcs ADS1015 ADC ultra-compact 12-precision ADC module development board

15th October 2016 0 comment

Espruino

Espruino LM35 temperature sensor example

by shedboy71 14th October 2016

written by shedboy71

In this example we will connect an LM35 temperature sensor to our Espruino

The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1/4°C at room temperature and ±3/4°C over a full -55 to +150°C temperature range

Here is a picture of the pins, its important to get these correct or you can damage the sensor

lm35-temperature-sensor-pinout

I purchased a small module, which looks like this. This was clearly labelled and helps avoid any mistakes with wiring, I also prefer using cables to modules rather than breadboards

lm35-module

Schematics and Parts

You will need

Espruino
LM35 sensor or module
Hook up wire (dupont cables)

Very simple to connect Vcc is 3.3v, Gnd is any Gnd and out goes to Espruino A1, you can see this below

espruino-and-lm35_bb

Code

[codesyntax lang=”javascript”]

function getTemp() {
  var val = analogRead(A1); // read voltage
  var millivolts = val * 3300;
  var celsius = millivolts/10;
  return celsius; // and return the temperature
}

function checkTemp() {
 var temp = getTemp();
 console.log("Temperature: " + temp + " C");
}
setInterval(checkTemp, 1000);

[/codesyntax]

Results

Here are the results via the console window of the Espruino Web IDE

Temperature: 17.64431219958 C
Temperature: 17.72487983520 C
Temperature: 18.20828564888 C
Temperature: 20.22247653925 C
Temperature: 21.59212634470 C
Temperature: 22.55893797207 C
Temperature: 23.28404669260 C
Temperature: 24.08972304875 C
Temperature: 24.41199359121 C
Temperature: 24.73426413366 C

Links

LM35 datasheet
5PCS LM35D Temperature Sensor TO92 Packing

14th October 2016 0 comment

Espruino

Espruino and an MCP9808 digital temperature sensor

by shedboy71 14th October 2016

written by shedboy71

MCP9808 digital temperature sensor example

The MCP9808 digital temperature sensor converts temperatures between -20°C and +100°C to a digital word with ±0.5°C (max.) accuracy. The MCP9808 comes with user-programmable registers that provide flexibility for temperature sensing applications. The registers allow user-selectable settings such as Shutdown or low-power modes and the specification of temperature Event and Critical output boundaries. When the temperature changes beyond the specified boundary limits, the MCP9808 outputs an Event signal. The user has the option of setting the event output signal polarity as an active-low or active-high comparator output for thermostat operation, or as temperature event interrupt output for microprocessor-based systems.

The event output can also be configured as a Critical temperature output. This sensor has an industry standard 2-wire, SMBus and Standard I2C™Compatible compatible (100kHz/400kHz bus clock) serial interface, allowing up to eight sensors to be controlled in a single serial bus.
Features

Accuracy:
±0.25°C (typical) from -40°C to +125°C
±0.5°C (maximum) from -20°C to +100°C

User Selectable Measurement Resolution:
0.5°C, 0.25°C, 0.125°C, 0.0625°C

User Programmable Temperature Limits:
Temperature Window Limit
Critical Temperature Limit

User Programmable Temperature Alert Output
Operating Voltage Range: 2.7V to 5.5V

More details about the sensor at http://www.microchip.com/wwwproducts/en/MCP9808

This typically comes in a breakout such as the one in the breakout below

mcp9808

Connection

Here is the connections I used to connect the MCP9808 module to my Espruino

MCP9808 Pin	Espruino Pin
GND	GND
VCC	3.3v
SDA	B7
SCL	B6

Layout

This is a layout of the connection above

espruino-and-mcp9808_bb

Code

[codesyntax lang=”javascript”]

require("MCP9808");

I2C1.setup({scl:B6,sda:B7, bitrate: 60000});
var mcp = require("MCP9808").connect(I2C1, 0b000);

setInterval(function() {
  var temperature = mcp.getTemperature();
  console.log("Temperature: " + temperature + " C");
}, 1000);

[/codesyntax]

Results

You should see something like this in the console window of the web ide

Temperature: 19.625 C
Temperature: 19.625 C
Temperature: 19.625 C
Temperature: 19.625 C
Temperature: 19.6875 C
Temperature: 19.625 C
Temperature: 19.6875 C
Temperature: 19.6875 C
Temperature: 19.625 C
Temperature: 19.6875 C
Temperature: 19.6875 C
Temperature: 19.75 C
Temperature: 23.5 C
Temperature: 25.1875 C
Temperature: 26 C
Temperature: 26.625 C
Temperature: 27.125 C
Temperature: 27.625 C
Temperature: 27.625 C

Links
Adafruit MCP9808 High Accuracy I2C Temperature Sensor Breakout Board [ADA1782]

14th October 2016 0 comment

Espruino

More Espruino 7 Segment display examples

by shedboy71 13th October 2016

written by shedboy71

In a previous post we showed how to connect a MAX 7219 7 Segment display – Espruino and MAX7219 7 segment display example . Here are some more examples

Counter example

This example increments a counter and displays the result on the 7 segment display

[codesyntax lang=”javascript”]

require("MAX7219");

SPI1.setup({mosi:B5, sck:B3});
var disp = require("MAX7219").connect(SPI1,B4);
disp.on();


setTimeout(function() {
  var n = 0;
  setInterval(function() {
    disp.set(n++); // it can display integers
  }, 100);
}, 2000);

[/codesyntax]

Display a random number

This example just displays a random nuber every second between 1 and 1000

[codesyntax lang=”javascript”]

require("MAX7219");

SPI1.setup({mosi:B5, sck:B3});
var disp = require("MAX7219").connect(SPI1,B4);
disp.on();


setInterval(function() {
   // get a random number between 1 and 1000
  var n = 1 + Math.floor(Math.random()*1000);
  disp.set(n);
}, 1000);

[/codesyntax]

Simply random dice

This example when you press the user button on your Espruino will generate a random number between 1 and 6 and display it on your Espruino

[codesyntax lang=”javascript”]

require("MAX7219");

SPI1.setup({mosi:B5, sck:B3});
var disp = require("MAX7219").connect(SPI1,B4);
disp.on();

setWatch(function(e) {
  var n = 1 + Math.floor(Math.random()*6);
  disp.set(n);
}, BTN1, { repeat: true, edge: 'rising' });

[/codesyntax]

13th October 2016 0 comment

Espruino

Espruino and MAX7219 7 segment display example

by shedboy71 13th October 2016

written by shedboy71

The MAX7219 is a compact, serial input/output common-cathode display drivers that interface microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8×8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs.

These chips are commonly found on 8×8 LED matrix modules and 7 segment modules, we will look at an example for the second example. The module we used was low cost and looked like this.

max7219-seven-segment-display

You can use these in a wide variety of projects that require some sort of numeric display such as temperature projects, stopwatch, distance meter and a clock – to fire off a couple of ideas. We will be revisiting these in future projects but lets take a look at how to connect these to our Espruino

Connection

Here are the connections that I used

Module Pin	Espruino Pin
GND	GND
VCC	VBAT
DIN	B5
CS	B4
CLK	B3

Layout

Here is a layout diagram showing the connections above

espruino-max7219-7segment

Code

A very simple example which displays some numbers on the display

[codesyntax lang=”javascript”]

require("MAX7219");

SPI1.setup({mosi:B5, sck:B3});
var disp = require("MAX7219").connect(SPI1,B4);
disp.on();
disp.set("01234567");

[/codesyntax]

Link

These modules are prices about the $2.50 mark
MAX7219 EWG 8-Digit Digital Tube Display Control Module Red

13th October 2016 0 comment

Espruino

Espruino and an ultrasonic distance sensor

by shedboy71 10th October 2016

written by shedboy71

The HC-SR04 is used to measure distances by using ultrasonic sounds. It works by sending out a burst of ultrasound and listening for the echo when it bounces off of an object. Here is a picture of the sensor

hc-sr04

The duration of this second pulse is equal to the time taken by the ultrasound to travel to the object and back to the sensor. Using the speed of sound, this time can be converted to distance.

Set low the Trig and Echo port when the module initializes , firstly, transmit at least 10us high level pulse to the Trig pin (module automatically sends eight 40K square wave), and then wait to capture the rising edge output by echo port, at the same time, open the timer to start timing. Next, once again capture the falling edge output by echo port, at the same time, read the time of the counter, which is the ultrasonic running time in the air. According to the formular: test distance = (high level time * ultrasonic spreading velocity in air) / 2, you can calculate the distance to the obstacle.

Specifications:

Input voltage: 5v
Current: Less than 2mA
Sensor angle: 15 degrees
Detection distance: 2cm-450cm
Accuracy: Up to 0.3cm
Input trigger signal: 10us TTL impulse
Echo signal : output TTL PWL signal

Layout

Here is an image of the layout I used

espruino-and-hcsr04_bb

Code

[codesyntax lang=”javascript”]

require("HC-SR04");

var sensor = require("HC-SR04").connect(A0,A1,function(dist) {
  console.log(dist+" cm away");
});
setInterval(function() {
  sensor.trigger(); // send pulse
}, 500);

[/codesyntax]

Testing

The best way of testing this is to have a ruler, place the HC-SR04 at one end and then an object at the other end and check the distance reported.

Here are some of my results

30.56777151007 cm away
29.68102170709 cm away
30.56777151007 cm away
26.53556957579 cm away
20.22793418482 cm away
14.32184587445 cm away
10.65772876404 cm away
9.30250736705 cm away
7.79670581483 cm away
8.09786612527 cm away
7.01034278200 cm away
5.32468159993 cm away
4.65125368352 cm away

Links

hc-sr04 ultrasonic ranging module smart car ultrasonic sensor module

10th October 2016 0 comment

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