Author

shedboy71

Espruino Pico time on LCD example

by shedboy71 6th August 2016

written by shedboy71

This is similar to the previous example, this time we will display the time on our LCD. If you are familiar with JavaScript you will recognise some of the code

These displays were used in old Nokia 5110 cell phones. It is a 84×48 pixel monochrome LCD display and you can use it for graphics, text or bitmaps. To use the display, you will require 5 digital output pins. Another pin can be used to control the backlight.

lcd5110b

lcd5110a

The display driver is a PCD8544 chip (which is another name for the display), and you can safely run the display off 3.3v

Here is the connections I used

Connection

LCD pin		Espruino Pico
GND		GND
LIGHT		N/C
VCC		3.3v
SCLK		B3
DN(MOSI)		B5
D/C		B13
CE		B14
RST		B15

Schematic

here is a schematic

pico and nokia5110_bb

Code

[codesyntax lang=”javascript”]

var g;

function draw() 
{
  g.clear();
  var t = new Date();
  var time = t.getHours()+":" + ("0"+t.getMinutes()).substr(-2);
  var secs = ("0"+t.getSeconds()).substr(-2);
  g.setFontBitmap();
  g.setFontVector(20);
  var timeWidth = g.stringWidth(time);
  g.drawString(time,(g.getWidth()-timeWidth-12)/2,10);
  g.setFontBitmap();
  g.drawString(secs,(g.getWidth()+timeWidth-8)/2,26);
  g.flip();
}

function onInit() 
{
  clearInterval();
  // Setup SPI
  var SPI1 = new SPI();
  SPI1.setup({ sck:B3, mosi:B5 });
  // Initialise the LCD
  g = require("PCD8544").connect(SPI1, B13 /*DC*/, B14 /*CE*/, B15 /*RST*/, function(){
    setInterval(draw, 1000);
  });
}

onInit();

[/codesyntax]

6th August 2016 0 comment

Espruino

Espruino Pico and Nokia 5110 display example

by shedboy71 6th August 2016

written by shedboy71

lcd5110b

lcd5110a

The display driver is a PCD8544 chip (which is another name for the display), and you can safely run the display off 3.3v

Here is the connections I used

Connection

LCD pin		Espruino Pico
GND		GND
LIGHT		N/C
VCC		3.3v
SCLK		B3
DN(MOSI)		B5
D/C		B13
CE		B14
RST		B15

Schematic

here is a schematic

pico and nokia5110_bb

Code

[codesyntax lang=”javascript”]

SPI1.setup({ sck:B3, mosi:B5 });
var g = require("PCD8544").connect(SPI1, B13 /*DC*/, B14 /*CE*/, B15 /*RST*/, function() {
  g.clear();
  g.drawString("Hello",0,0);
  g.drawString("World",0,5);
});

[/codesyntax]

Links

1pcs/lot nokia5110 LCD Module microcontroller development

6th August 2016 0 comment

Espruino

Espruino Pico

by shedboy71 5th August 2016

written by shedboy71

This piece of hardware is the Espruino Pico which is designed to be programmed in Javascript ,the Pico is designed to plug right into you computer’s USB type A connector, or a USB extension lead.

espruinopico

The Pico has the following feature swhich I found interesting

Features

22 GPIO pins : 9 Analogs inputs, 21 PWM, 2 Serial, 3 SPI, 3 I2C
All GPIO is 5 volt tolerant (Arduino compatible)
Two on-board LEDs and one button.
STM32F401CDU6 CPU – ARM Cortex M4, 384kb flash, 96kb RAM

espruinopico1

You need to setup a com port, I have tried this on Windows 7 and Windows 10

Non-Windows XP Users download version 1.4.0 drivers. Unzip the file, run the executable, and then go to C:\Program Files (x86)\STMicroelectronics\Software\Virtual comport driver in Windows Explorer and double-click either dpinst_amd64.exe for 64 bit systems, ordpinst_x86.exe for 32 bit.

There is a nice webide that can be added to chrome as follows

Install Chrome
Click here to get the Espruino Web IDE and click +FREE in the top right to install it.

Start the webdide and click on the connect and select the correct com port

espruino ide1
Code Example

This simply switches the 2 led’s on and off
[codesyntax lang=”javascript”]

var on = false;
var off = true;
setInterval(function() {
on = !on;
LED1.write(on);
off = !off;
LED2.write(off);
}, 500);

[/codesyntax]

5th August 2016 0 comment

Code Micro Bit

Blinking image using Microsoft Block Editor for the Micro:Bit

by shedboy71 26th July 2016

written by shedboy71

Go to the micro:bit web site and follow the hyperlink to Create Code. Choose the Microsoft Block Editor and make a New Project.

Look in the Basic section for the forever, show leds, pause and clear screen blocks.

basic show leds

Now create the following

flashing led matrix

Click the Run button in the browser and you can see a preview of the image flashing on and off on the right hand side of the page.

Simulations are fine but we want to see this on our Micro bit, Click on the Compile button to create a .hex file for the micro bit. You will be prompted to download the file, you can either download to your computer or straight to your Micro Bit. The Micro Bit is similar to the MBed system in that it has an online compiler which creates hex files that you save to your computer or can save to your device as it appears as a drive on your computer, I save to my computer and drag it into my Micro Bit’s drive – just my preference

Once complete you should see the pattern flashing on your Micro Bit

Incidentally a nice feature is the ability to convert your code using the convert button

26th July 2016 0 comment

Hardware

Micro Bit overview

by shedboy71 26th July 2016

written by shedboy71

In the last couple of days I managed to get my hands ona Micro Bit, if you have no idea what i am talking about then this will introduce you to this intriguing board

The Micro Bit measures 4 × 5 cm the device has an ARM Cortex-M0 processor, accelerometer and magnetometer sensors, Bluetooth and USB connectivity, a display consisting of 25 LEDs, two programmable buttons, and can be powered by either USB or an external battery pack. The device inputs and outputs are through five ring connectors that are part of the 23-pin edge connector.

microbit

Hardware

The size of the device is described as half the size of a credit card, measuring 43 x 52 mm and, as of the start of final manufacturing,[18] includes:

Nordic nRF51822 – 16 MHz 32-bit ARM Cortex-M0 microcontroller, 256 KB flash memory, 16 KB static ram, 2.4 GHz Bluetooth low energy wireless networking. The ARM core has the capability to switch between 16 MHz or 32.768 kHz.
NXP/Freescale KL26Z – 48 MHz ARM Cortex-M0+ core microcontroller, that includes a full-speed USB 2.0 On-The-Go (OTG) controller, used as a communication interface between USB and main Nordic microcontroller.
NXP/Freescale MMA8652 – 3-axis accelerometer sensor via I²C-bus.
NXP/Freescale MAG3110 – 3-axis magnetometer sensor via I²C-bus (to act as a compass and metal detector).
MicroUSB connector, battery connector, 23-pin edge connector.
Display consisting of 25 LEDs in a 5×5 array.
Three tactile pushbuttons (two for user, one for reset).

I/O includes three ring connectors (plus one power one ground) which accept crocodile clips or 4 mm banana plugs as well as a 23-pin edge connector with two or three PWM outputs, six to 17 GPIO pins (depending on configuration), six analog inputs, serial I/O, SPI, and I²C.Unlike early prototypes, which had an integral battery, an external battery pack (AAA batteries) can be used to power the device as a standalone or wearable product.

Software

There are four official code editors in the BBC micro:bit web site:

CodeKingdoms, using JavaScript
Microsoft Block Editor, based on Blockly;
Microsoft TouchDevelop;
MicroPython.

The Python programming experience on the Micro Bit is provided by MicroPython. Users are able to write Python scripts in the Micro Bit web editor which are then combined with the MicroPython firmware and uploaded to the device. Users can also access the MicroPython REPL running directly on the device via the USB serial connection, and this allows to interact directly with the Micro Bit’s peripherals.

The Micro Bit was created using the ARM mbed development kits. The run-time system and programming interface utilize the mbed cloud compiler service to compile the user’s code. The compiled code is then flashed onto the device using USB or Bluetooth connections. The device will appear as a USB drive when connected to a computer and code can be flashed using drag and drop

26th July 2016 0 comment

Code

stm32f0discovery and RGB led example

by shedboy71 11th February 2016

written by shedboy71

In this example we will do a simple flashing led project for a stm32f0discovery board, I used Coocox IDE 1.7.8. I did try the newer version and didn’t really like the way you selected a chip and imported components via the repository.

This example will involve connecting a common anode RGB led to the stm32f0discovery and then we will flash the red, green and blue individually. Here is a picture of the board, we will connect the following

command anode – 3v.
RED – PC0
GREEN – PC1
BLUE – PC2

STM32F0-Discovery_rgb

Here is a typical RGB led module that I use in many simple beginner projects, I find it easier than messing about with breadboards.

rgb led module

Code

As stated I used Coocox for this, I will be trying various compilers such as MDK and IARs offerings eventually.In this example I pulled in the RCC, GPIO, CMSIS boot and MO CMSIS core. You can see this in the screenshot below

coocox repository

There are a few comments in the code, I’ll go through some of this in more detail in a later tutorial

[codesyntax lang=”cpp”]

/**
/*
 * @Project: RGB Led example
 * @Microntroller: STM32F030R8T6
 */

#include <stdint.h>
#include <system_stm32f0xx.h>
#include <stm32f0xx_gpio.h>
#include <stm32f0xx_rcc.h>


int main(void)
{
	GPIO_InitTypeDef InitGpio;
	unsigned int i = 0;

	// Initialises the system clock
	SystemInit();

	// Enables the clock for GPIOC
	RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);

	// Configures the GPIOC pin8 and pin9, since leds are connected
	// to PC8 and PC9 of GPIOC
	InitGpio.GPIO_Pin = (GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2);
	InitGpio.GPIO_Mode = GPIO_Mode_OUT;
	InitGpio.GPIO_Speed = GPIO_Speed_Level_1;
	InitGpio.GPIO_OType = GPIO_OType_PP;
	InitGpio.GPIO_PuPd = GPIO_PuPd_NOPULL;

	// Initialises the GPIOC
	GPIO_Init(GPIOC, &InitGpio);
	GPIO_SetBits(GPIOC, 0xFF); //common anode led - so outputs high
    while(1)
    {
    	// Turn ON the Red Led
    	GPIO_ResetBits(GPIOC, (GPIO_Pin_0));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);
    	// Turn OFF the Led
    	GPIO_SetBits(GPIOC, (GPIO_Pin_0));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);

    	// Turn ON the Green Led
    	GPIO_ResetBits(GPIOC, (GPIO_Pin_1));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);
    	// Turn OFF the Led
    	GPIO_SetBits(GPIOC, (GPIO_Pin_1));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);

    	// Turn ON the Blue Led
    	GPIO_ResetBits(GPIOC, (GPIO_Pin_2));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);
    	// Turn OFF the Led
    	GPIO_SetBits(GPIOC, (GPIO_Pin_2));
    	// Delay
    	for (i = 0; i < 0x0FFFFF; i++);
    }
}

[/codesyntax]

With a bit of luck you will see your RGB led cycling through the three main colours

11th February 2016 0 comment

Code

Analog Joystick

by shedboy71 8th February 2016

written by shedboy71

This example shows how to connect a joystick to your St Nucleo. This could be used for games or perhaps navigating through a menu for example Here is a picture of the joystick I am using, this is commonly found for sale on many sites. Usually part of a sensor kit, links at the bottom

joystick

Here is the pinout and where I connected it to on my ST Nucleo board, the pinout is underneath

Pin Number	Label	Signal	Arduino Connection
1	GND		Ground
2	+5V		5V
3	VRx	Voltage proportional to X position	Connected to analogue pin 0
4	VRy	Voltage proportional to Y position	Connected to analogue pin 1
5	SW	Joystick pushbutton	Connected to Digital pin 7

Here is the STM32 nucleo pinout

nucleo pins

Code

Nothing fancy in this example, we will simply output the values from the X and Y pins. Typically you would read these values and them perform actions based on the various positions such as left, right and up and down. A later update will show this.

This requires the https://developer.mbed.org/users/happinesstaker/notebook/sparkfun-analog-joystick/ to be imported into your project

[codesyntax lang=”cpp”]

#include "mbed.h"
#include "SparkfunAnalogJoystick.h"

 
SparkfunAnalogJoystick joysttick(A0, A1, D7);

 
// Test program for the library
// It would output all data about the joystick
// It would also draw a compass to indicate the joystick status on the LCD display
 
int main() {


    while(1) {
        printf("X-Axis: %f\n\r", joysttick.xAxis());
        printf("Y-Axis: %f\n\r", joysttick.yAxis());
        printf("Button: %d\n\r\n", joysttick.button());
   
        wait(1);
    }
}

[/codesyntax]
Links
Arduino joystick at Amazon UK

Arduino joystick at Amazon

8th February 2016 0 comment

Code

STM32 Nucleo board and an AD Keypad

by shedboy71 7th February 2016

written by shedboy71

I purchased this module as part of a microcontroller kit, its an interesting little module as it has 16 buttons but with only 1 I/O line is required, an analog input. You connect this to your ST Nucleo and read in the value and display it via the serial port.

The concept is straightforward you use a resistor network as voltage dividers, and then let each button feed a different voltage to the analog pin. So by detecting the voltage you can tell which button has been pressed. You can only detect one button at a time

A_D-Keypad-2

Here is the schematic of the module, hopefully you can see what I described earlier

AD-Keypad-Schematic

You will have to wire Vcc of the module to 3.3v otherwise the readings will be incorrect, the A0 of the module is connected to A0 (Arduino)

Code

[codesyntax lang=”cpp”]

#include "mbed.h"

 
Serial pc(USBTX, USBRX);
AnalogIn input(A0);
 
int main()
{
 pc.printf("Hello World\n");
 while (1) 
 {

 float reading = input.read()*100.0f;
 if (reading < 92.00)
 {
 // print the percentage and 16 bit normalized values
 pc.printf("value: %3.2f%\n", input.read()*100.0f);
 wait(0.4f);
 }
 
 }
}

[/codesyntax]

Output

Pressing the keys from K0 to K16 outputted the following in a serial monitor such as TeraTerm

percentage: 0.00
percentage: 4.52
percentage: 10.70
percentage: 17.02
percentage: 23.25
percentage: 29.26
percentage: 35.41
percentage: 41.95
percentage: 47.94
percentage: 66.08
percentage: 60.51
percentage: 72.14
percentage: 78.61
percentage: 84.66
percentage: 90.72

So using a switch case you can use this module in your own examples, best practice would be to have a high and low value and check between the range. For example Key 1 is 4.52 so you could check for a range between 3 and 5

Links

AD Keypad 16 4×4 Accessory board matrix buttons controlled ADC

7th February 2016 0 comment

Code

BMP180 and LCD keypad example

by shedboy71 5th February 2016

written by shedboy71

In this example we will take the previous bmp180 example – Nucleo and BMP180 example. This time again we will connect an LCD Keypad shield and display the temperature and pressure on the display.

Code

You will need the freetronics lcd keypad shield library

[codesyntax lang=”cpp”]

#include "mbed.h"
#include "freetronicsLCDShield.h"
#include "BMP180.h"

I2C i2c(I2C_SDA, I2C_SCL);
freetronicsLCDShield lcd(D8, D9, D4, D5, D6, D7, D1, A0);
BMP180 bmp180(&i2c);


int n=0;

int main() 
{
    lcd.cls();
    lcd.printf("Initiliazing");
    lcd.setCursorPosition(1, 0);
    
    while(1) {
        if (bmp180.init() != 0) {
            lcd.printf("Comms error");
        } else {
            lcd.printf("Initialized BMP180");
            break;
        }
        wait(1);
    }
    
    
    while(1)
    {
        bmp180.startTemperature();
        wait_ms(5);     // Wait for conversion to complete
        float temp;
        lcd.cls();
        if(bmp180.getTemperature(&temp) != 0) 
        {
            lcd.setCursorPosition(0, 0);
            lcd.printf("Error temp");
            continue;
        }
        
       bmp180.startPressure(BMP180::ULTRA_LOW_POWER);
        wait_ms(10);    // Wait for conversion to complete
        int pressure;
        if(bmp180.getPressure(&pressure) != 0) 
        {
            lcd.printf("Error pres");
            continue;
        }

        lcd.setCursorPosition(0, 0);
        lcd.printf("Temp : ");
        lcd.setCursorPosition(0, 7);
        lcd.printf("%2.1f",temp);
        lcd.setCursorPosition(1, 0);
        lcd.printf("Pres : ");
        lcd.setCursorPosition(1, 7);
        lcd.printf("%d",pressure);
        wait_ms(1000);


    }
}

[/codesyntax]

Links
1PCS GY-68 BMP180 Replace BMP085 Digital Barometric Pressure Sensor Module For Arduino

1602 LCD Board Keypad Shield Blue Backligh

5th February 2016 0 comment

Code

Nucleo and BMP180 example

by shedboy71 5th February 2016

written by shedboy71

In this example we will connect a BMP180 sensor to our Nucleo board. Typically this is in some sort of breakout or module such as the one below

GY-68-1

Description

This precision sensor from Bosch is the best low-cost sensing solution for measuring barometric pressure and temperature. Because pressure changes with altitude you can also use it as an altimeter! The sensor is soldered onto a PCB with a 3.3V regulator, I2C level shifter and pull-up resistors on the I2C pins. The BMP180 is the next-generation of sensors from Bosch, and replaces the BMP085. The good news is that it is completely identical to the BMP085 in terms of firmware/software/interfacing – you can use any example code/libraries for BMP085 as a drop-in replacement.

Specification

Pressure sensing range: 300-1100 hPa (9000m to -500m above sea level)
Up to 0.03hPa / 0.25m resolution
-40 to +85°C operational range, +-2°C temperature accuracy

The connections were as follows, crucially this is an I2C device and it runs on 3.3v. You can see the I2C pins at D15,D14

nucleo pins

Code

You will need to import the bmp180 library

[codesyntax lang=”cpp”]

#include <stdio.h>
#include "mbed.h"
#include "BMP180.h"
 
I2C i2c(I2C_SDA, I2C_SCL);
BMP180 bmp180(&i2c);
 
int main(void) {
 
    while(1) {
        if (bmp180.init() != 0) {
            printf("Error communicating with BMP180\n");
        } else {
            printf("Initialized BMP180\n");
            break;
        }
        wait(1);
    }
 
    while(1) {
        bmp180.startTemperature();
        wait_ms(5);     // Wait for conversion to complete
        float temp;
        if(bmp180.getTemperature(&temp) != 0) {
            printf("Error getting temperature\n");
            continue;
        }
 
        bmp180.startPressure(BMP180::ULTRA_LOW_POWER);
        wait_ms(10);    // Wait for conversion to complete
        int pressure;
        if(bmp180.getPressure(&pressure) != 0) {
            printf("Error getting pressure\n");
            continue;
        }
 
        printf("Pressure = %d Pa Temperature = %f C\n", pressure, temp);
        wait(1);
    }
}

[/codesyntax]

Results

Open a serial monitor such as TeraTerm, if all is correct you should see something like the following

nucleo and bmp180

Links
1PCS GY-68 BMP180 Replace BMP085 Digital Barometric Pressure Sensor Module For Arduino

5th February 2016 0 comment

Code

AM2303 and LCD Keypad shield example

by shedboy71 5th February 2016

written by shedboy71

In this example we take our Nucleo and AM2303 sensor example and we add an LCD Keypad shield and display the temperature and humidity on this. Here is a picture of that shield

lcd keypad shield

You will need to add the freetronics LCD shield library

Code

[codesyntax lang=”cpp”]

#include "mbed.h"
#include "AM2303.h"
#include "freetronicsLCDShield.h"

 
freetronicsLCDShield lcd(D8, D9, D4, D5, D6, D7, D1, A0);
 
 
/* Humidity sensor */
AM2303 h(D12);
 
/* The main function */
int main()
{
    /* Variables */
        lcd.cls();
    lcd.printf("AM2303 Humidity");
    lcd.setCursorPosition(1, 0);
    int state;
 
    /* Infinate loop */
    while(true) 
    {
        /* Wait for measurement */
        wait(2.0);
 
        /* Read the measured results */
        state = h.readData();
        lcd.setCursorPosition(1, 0);
        /* Show the data, otherwise error */
        if (state != AM2303::OK) 
        {
            lcd.printf("<Error: %d>\n", state);
        } 
        else 
        {
            
            lcd.printf("T:%2.1fC, H:%2.1f%%\n", h.readTemperature(), h.readHumidity());
        }
 

    }
}

[/codesyntax]

Links

DHT22 AM2302 Digital Temperature Humidity Sensor Chip Electronic Brick

1602 LCD Board Keypad Shield Blue Backlight

5th February 2016 0 comment

Code

Nucleo and AM2302 sensor example

by shedboy71 5th February 2016

written by shedboy71

AM2302 capacitive humidity sensing digital temperature and humidity module is one that contains the compound has been calibrated digital signal output of the temperature and humidity sensors. Application of a dedicated digital modules collection technology and the temperature and humidity sensing technology, to ensure that the product has high reliability and excellent long-term stability. The sensor includes a capacitive sensor wet components and a high-precision temperature measurement devices, and connected with a high-performance 8-bit microcontroller.

The best way to use this is to use a module/breakout like the following one
DHT22 AM2302 Digital Temperature Humidity Sensor Chip For Arduino

Schematic

In this example we connect the AM2302 to D12.

am2302 micro

The code example requires you to import the AM2303 library – Shigenori Inoue craeted the one I used.

Code

[codesyntax lang=”cpp”]

#include "mbed.h"
#include "AM2303.h"
 
 
 
/* Humidity sensor */
AM2303 h(D12);
 
/* The main function */
int main()
{
    /* Variables */
    int state;
 
    /* Show splash screen */
    printf("AM2303 Humidity");
    /* Infinate loop */
    while(true) 
    {
        /* Wait for measurement */
        wait(2.0);
 
        /* Read the measured results */
        state = h.readData();
 
        /* Show the data, otherwise error */
        if (state != AM2303::OK) {
            printf("<Error: %d>\n", state);
        } else {
            printf("T:%2.1fC, H:%2.1f%%\n", h.readTemperature(), h.readHumidity());
        }
 

    }
}

[/codesyntax]

Result

Using a terminal such as TeraTerm you should see something like the following

nucleo am2302 output

Link

DHT22 AM2302 Digital Temperature Humidity Sensor Chip Electronic Brick

5th February 2016 0 comment

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