The Edwin Robotics DRV8833 breakout board is capable of controlling up to 2 DC motors or one bi/uni-polar stepper motor a max current of 1.2A. The DRV8833 comes with 2 full H-bridges which give bi-directional control of your DC motors. It is similar to the L9110S in its voltage range ( 2.7V – 10.8V), but carrying 50% more oomph. This makes it ideal for projects where the motors will be run from a 9V battery.

The board can be powered using the provided screw terminals or through micro-USB, checkout out micro-USB to DC Jack adapter if you would like to use a standard power adapter with the board

 Hardware Required

Edwin Robotics DRV8833 Motor Driver	Arduino UNO	Male-Female Jumper wires
DC Geared Motor with Wheel	9V DC Battery Snapper	microUSB to DC Jack Female Connector

Features

• Dual-H-bridge motor driver: can drive two DC motors or one uni/bi-polar stepper motor
• Operating voltage: 2.7‌‌ V to 10.8 V
• Output current: 1.2 A continuous (2 A peak) per motor
• Motor outputs can be paralleled to deliver 2.4 A continuous (4 A peak) to a single motor
• Inputs are 3V- and 5V-compatible
• Under-voltage lockout and protection against over-current and over-temperature
• Reverse-voltage protection circuit
• Current limiting can be enabled by adding sense resistors (not included)

Pinouts:

DRV8833 Motor driver pin description

 

Power

• Vm – This is the voltage supply for the motors. Keep this voltage between 2.7V and 10.8V. This Supply Pin is not Reverse polarity protected, so care must be taken while connecting jumper wires to it.
• Power Screw Terminal: The Power Screw terminal is labelled with + and -, connect your power supply according to label, this terminal is reverse polarity protected.
• USB Power In: You can power the board with micro USB connector provided; this is reverse polarity protected as well.
• GND – This is the shared logic and motor ground. All grounds are connected

Current Limiting Pins

As/ Bs: The DRV8833 can perform current limiting for each motor H-bridge by connecting a resistor between As/Bs and ground to set the Motor A/ Motor B Limit.

By default , the current limiting feature is disabled and can be enabled by modifying the jumper, refer the image below:

Current Limiting and Status LED’s Jumper Pads.

The Current limiting can be enabled by cutting out the solder joint between the jumper Pads for Asen and Bsen. Once the jumper pads are modified you can either solder SMD resistor (1206 Size) on board or you can use the AS/BS headers pin to make connection with through hole resistors. You can also totally disable current limiting whenever needed by soldering the two jumpers on the back.

The current limiting rule is: LimitCurrent (amps) = 0.2 V / RSENSE

Add 1206 resistors here to modify the current supplied to the respective motors

 

Connection’s

You can use any stepper motor or dc motor rated upto 10.8v with this board. We have used the following kit to get it tested:

Robotics Kit

 

 Refer the image below for the motor connections

Motor Connections

Power Supply Connections

Arduino DRV8833 Connections

Test Codes

#define Ain1 5
#define Ain2 6
#define Bin1 9
#define Bin2 10

int speed = 0;

void setup() {
pinMode(Ain1, OUTPUT);  //Ain1
pinMode(Ain2, OUTPUT);  //Ain2
pinMode(Bin1, OUTPUT);  //Bin1
pinMode(Bin2, OUTPUT);  //Bin2

}

void loop() {

    digitalWrite(Ain1,HIGH);
    digitalWrite(Ain2,LOW);
    digitalWrite(Bin1,HIGH);
    digitalWrite(Bin2,LOW);
    delay(700);
    digitalWrite(Ain1,LOW);
    digitalWrite(Ain2,LOW);
    digitalWrite(Bin1,LOW);
    digitalWrite(Bin2,LOW);

    digitalWrite(Ain1,LOW);
    digitalWrite(Ain2,HIGH);
    digitalWrite(Bin1,LOW);
    digitalWrite(Bin2,HIGH);
    delay(700);
    digitalWrite(Ain1,LOW);
    digitalWrite(Ain2,LOW);
    digitalWrite(Bin1,LOW);
    digitalWrite(Bin2,LOW);
  
}

Download DRV8833 Datasheet

References:

Adafruit Hookup Guide

Polulu Blog

Digital AC Mains Switch

Product Link

Looking to control lights and bulbs with microcontroller ? then, this digital AC switch boards is suitable for your application, this board is a great alternative for the solid state relay boards. This board comes pre-assembled with everything, all you need to do is to connect supply, load and digital interface pins.

The board posses following Electrical Characteristics:

The board is suitable to use with 3.3, 5, 12 and 24 volt systems, thus making it ideal for any voltage, the maximum ratings are mentioned in the table above and can change based on working conditions. The board is not tested on 110v lines, but its parts are compatible to work with 110V Supply. The on-board fuse are easily replaceable, in case of any damage. The mounting holes will give you the flexibility to screw it to any surface.

Connections:

All the connections must be made via screw terminals and we will recommend you to keep ready one screw driver beside you, before making connections. There are 4 screw terminals on board, please refer the image below for better idea:

Digital AC Mains Switch Interface

Refer the below table for Silkscreen/legend description:

So you need to use ‘S’ and ‘Gnd’ Pin to interface your Microcontroller board with this unit, there are two ‘L’ and ‘N’ screw terminals, you just need to connect supply to any one from the both, the second one is to extend the supply to other boards/ peripherals. Loads such as light/fan,etc. must be connected across “Load” and ‘N’ Pin to establish the connection of the load with the board. You can use jumper wires to to connect microcontroller board and screw the jumper wires to interface “S and GND “pins.

Connection Diagram:

Digital AC Mains Switch connections

The microcontroller interface just needs 2 Pins, we connected Arduino ground with module ground and Arduino pin A0 as digital control for module. The load will go across Screw terminal where light bulb is connected and the power supply will go into either of the one Screw terminal.

Working with AC voltages is DANGEROUS, care must be taken to prevent any short circuits or mistakes in connection. And as always, you are doing this project at your own risk and Edwin Robotics or the Author cannot be held liable for any damages.

Sample Program:

To test the connections and board functions, we will recommend you to use the Blinking LED code from the Arduino examples, make sure to change the pin number in the code as follows:

#define LOAD A0

void setup() {
// initialize digital pin LOAD as an output.
pinMode(LOAD, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
digitalWrite(LOAD, HIGH); // turn the BULB on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(LOAD, LOW); // turn the BULB off by making the voltage LOW
delay(1000); // wait for a second
}

Buy this Product here

Introduction

The MCP23S17 is a SPI Based Port Expander which can add 16 more digital I/O pins to your Arduino or Raspberry Pi. Thanks to the wide operating voltage of 1.8 – 5.5V,  you can add 5V I/O pins to the Raspberry Pi or 3.3V based Arduino thereby avoiding a level shifter and simplifying connections.

Hardware Required:

MCP23S17 Port Expander

Breadboard

Jumper Wires

Board Overview

The board consists of 2 Port Banks (A and B), a 3-way switch, power and SPI headers

3-Way switch is used to set the address of the Port Expander, the switch positioned towards ON sets the address as ‘0’. The image above sets the address as ‘7’

INT B Interrupt output for PortB

B.0 – B.7 Bidirectional I/O

INT A Interrupt output for PortA

A.0 – A.7 Bidirectional I/O

VCC Power supply pin for the MCP23S17, connect to a voltage source between 1.8V -5V

GND connect to ground of power supply

SO, SI, SCK & CS SPI Pins

RESET connect to ground to reset the port expander

Note: The silkscreen on Port A is reversed, meaning INT A actually is A.7 and A.7 actually is INT A

Enabling SPI on the Raspberry Pi

By default the SPI peripheral is not enabled, we cannot continue unless this is done first. Have a look at the tutorial by SparkFun on how to do this.

Interfacing the MCP23S17 Port Expander with the Raspberry Pi

Interfacing the MCP23S17 to the Raspberry Pi

Connections from Raspberry Pi to MCP23S17 Port Expander

Installing the Python Library

In order to get started the python library needs to be installed first. Run the following command in terminal to install the library

sudo pip install RPiMCP23S17

Sample Code

The below code will turn ON and OFF all the pins at an interval of 1 second.

from RPiMCP23S17.MCP23S17 import MCP23S17
import time

mcp = MCP23S17(bus=0x00, ce=0x00, deviceID=0x00)
mcp.open()

for x in range(0, 16):
    mcp.setDirection(x, mcp.DIR_OUTPUT)

print "Starting blinky on all pins (CTRL+C to quit)"
while (True):
    for x in range(0, 16):
        mcp.digitalWrite(x, MCP23S17.LEVEL_HIGH)
    time.sleep(1)
    for x in range(0, 16):
        mcp.digitalWrite(x, MCP23S17.LEVEL_LOW)
    time.sleep(1)

Further Reading

RPiMCP23S17 Github Repo

Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from fixed and mobile devices, and building personal area networks (PANs). Range is approximately 10 Meters (30 feet). The Bluetooth Module Bluetooth HC-06s with Bluetooth V2.0 have proven themselves to be very reliable and easy to use module, these module uses serial interface for communication , thus very easy to interface with any microcontroller/Computer over RX/TX Lines.

You can refer the list of items we are covering in this hookup guide here:

1. Hardware Needed
2. Board Description
3. Pin Description
4. Jumper Description
5. AT Commands and Arduino Interface Code
6. Datasheets

Hardware Needed:

Edwin Robotics Bluetooth Module - HC06

Male-Female Jumper Wires

Board Description:

The HC-06 modules are based on the Cambridge Silicon Radio BC417 2.4 GHz Bluetooth Radio chip. This is a complex chip which uses an external 8 Mbit flash memory. These low-cost Bluetooth Sub-modules work well with Arduino and other Microcomputers. HC-06 is a Slave only device.The module has two modes of operation, Command Mode where we can send AT commands to it and Data Mode where it transmits and receives data to and from another Bluetooth module. By default the device was in Command mode and needs to pair with some device to get it into data mode.

Edwin Robotics Bluetooth Module – HC06

There are two LED’s on board for indication, refer the diagram below, for better idea:

LED Indication

Pins/Headers:

Board needs 4-lines to communicate most of the times, i.e Vcc, Gnd, RX and TX pin. There are two additional pin onboard, one is Key pin and the other is Reset pin, this Reset pin can be used to send reset signal from microcontroller to reset the bluetooth module. Refer the table and image below in detail:

Silkscreen

Jumper’s:

There are Jumpers provided on the bottom side of the module, refer the below image and table for better idea:

Jumper Settings

AT Commands:

The bluetooth module supports some limited commands set, which you can refer from the datasheet, we had addded the code below, to get the AT command interface working on any Arduino board. All the Supported commands are well documented in the code below, make sure of following things:

• nl/cr line endings not required in the serial window.
• AT commands are required to be in upper case
• Default Serial Communication baud rate: 9600

/**********************************************************************************
AT_Command_Interface.ino

Description:
  Sample AT Command Interface code for Arduino and HC06 Bluetooth Module

Tutorial Link:  
  learn.edwinrobotics.com/hc-06-bluetooth-module-hookup-guide

Created by:
  Abhishek Nair @ Edwin Robotics
  Feb 9th 2017

Distributed as-is; no warranty is given.   
**********************************************************************************/
#include <SoftwareSerial.h>

SoftwareSerial mySerial(2, 3); // RX, TX

void setup() {

Serial.begin(9600);
Serial.println("------------------------------------------------------------------------------------------");
Serial.println("             Edwin Robotics HC06 Bluetooth Module Serial Interface ");
Serial.println("------------------------------------------------------------------------------------------");
Serial.println("                 Connect Bluetooth Module RX -> Arduino pin 3 ");
Serial.println("                 Connect Bluetooth Module TX -> Arduino pin 2 ");
Serial.println("------------------------------------------------------------------------------------------");
Serial.println("");
Serial.println("Entered AT command Mode, please Enter AT Commands from the list of supported commands:");
Serial.println("******************************************************************************************");
Serial.println("AT              > connection test command. Returns OK");
Serial.println("");
Serial.println("AT+BAUDx        > sets the baud rate to respective board rate for entered 'x' value(refer values below) and returns OKBaud_Rate");
Serial.println("                   1: 1200  2: 2400  3: 4800  4: 9600  5: 19200  6: 38400  7: 57600  8: 115200  9: 230400  A: 460800  B: 921600  C: 1382400");
Serial.println("");
Serial.println("AT+NAME(myName) > sets the name to (myName), returns OKsetname");
Serial.println("");
Serial.println("AT+PIN9999      > changes the PIN to 9999, returns OKsetPIN");
Serial.println("");
Serial.println("AT+VERSION      > returns the firmware version : hc01.comV2.0");
Serial.println("");
Serial.println("AT+LED0         > turn off the blue LED, returns LED OFF");
Serial.println("");
Serial.println("AT+LED1         > turn on the blue LED, returns LED ON");
Serial.println("");
Serial.println("AT+PN           > sets no parity");
Serial.println("");
Serial.println("AT+PE           > sets even parity");
Serial.println("");
Serial.println("AT+PO           > sets odd parity");
Serial.println("******************************************************************************************");
Serial.println("");

mySerial.begin(9600);
delay(300);
Serial.println();
Serial.println("Note: if 'Version: hc01.comV2.0' is not printed below, make sure that your connections are correct or your module is not connected to any other device,try restarting the device/Serial Window");
Serial.println("----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------");
Serial.print("Version: ");
mySerial.write("AT+VERSION");
}

void loop()
{
  if (mySerial.available())
    Serial.write(mySerial.read());

  if (Serial.available())
    mySerial.write(Serial.read());
}

Datasheets:

Download English Datasheet : In this datasheet, the photo would appear to be of an older version but the commands, pins and functionalities are same.
Download Chinese Datasheet

Other command which we did not added in the code but can be found in the data sheet is the ROLE command:
AT+ROLE=S puts the module in to SLAVE mode, returns OK+ROLE:S
AT+ROLE=M puts the module in to MASTER mode, returns OK+ROLE:M
We did not seen any affect or usage of this command, we will update this section , if there is some information on this part from the manufacturer.

New to Electronics or programming ? No need to worry now, the Raspberry pi is only for you. If you are beginner, we will recommend you to go through our Raspberry Pi Blogs. We will recommend you to go through these set of videos before getting started. Lets have a look at set of contents we are covering in this tutorial.

• Hardware Needed

• Using RasPiO Portsplus with Raspberry Pi

• Getting Started With Breadboard and LED

• Getting Started with Switch, transistor and buzzer on breadboard

• Pi Wedge Hookup Guide

• Getting Started with Physical Computing on Raspberry Pi

• Getting Started with Scratch

• Test blinking LED using Python/Scratch

• Testing Switch using Python/Scratch

• Testing Capacitive Touch using Python/Scratch

• Testing Buzzer using Python/Scratch

• References

Hardware Needed

        Raspberry Pi Electronics Starter Kit

RasPiO Portsplus

The RasPiO® Portsplus board is designed for the new Raspberry Pi 3/2/A+/B+. It labels the ports clearly for you so that you don’t need to count pins. This will help you avoid wiring errors and damage.You can slip it over the GPIO header if you want, or hold it next to the header.RasPiO® Portsplus has GPIO port numbers on one side and Pin numbers on the other side, so you can use whichever numbering system you prefer. At just 1mm thick, it leaves plenty of space for attaching your wires. It’s thick enough not to feel flimsy, but thin enough not to be clunky. Refer the image below, to see how to use RasPio Portsplus.

Raspberry Pi with RasPiO Portsplus and jumpers

Breadboard and LED

In this step we will start with the breadboard, breadboards are preferred platform to start building circuits because it don’t need any soldering, thus giving you the flexibility to try, test and modify your circuit at any point of time. They allow you to make quick circuits, test out ideas and allow prototyping before making a permanent Printed Circuit Board. They are inexpensive and reusable and they are easily available in any electronics store. Once you understood the basics regarding breadboading , then will go ahead with the basic essential component of all the electronics circuit i.e LED.We have already added all the details regarding this step in the following blog, refer this blog on ” How to Breadboard LED “

Getting Started with Switch, transistor and buzzer on breadboard

One of the most elementary and easy-to-overlook circuit component is the switch. Switches don’t require any fancy equations to evaluate. All they do is select between an open circuit and a short circuit. Simple. But how could we live without buttons and switches!? What good is a blinky circuit with no user input? Or a deadly robot with no kill switch? or any remote or mobile with no buttons? What would our world be without with big red buttons.A switch is a component which controls the open-ness or closed-ness of an electric circuit. They allow control over current flow in a circuit (without having to actually get in there and manually cut or splice the wires). Switches are critical components in any circuit which requires user interaction or control.A switch can only exist in one of two states: open or closed. In the off state, a switch looks like an open gap in the circuit. This, in effect, looks like an open circuit, preventing current from flowing.In the on state, a switch acts just like a piece of perfectly-conducting wire. A short. This closes the circuit, turning the system “on” and allowing current to flow unimpeded through the rest of the system.

A circuit with an LED, resistor, and a switch. When the switch is closed, current flows and the LED can illuminate. Otherwise no current flows, and the LED receives no power.

There are tons and tons of switches out there: toggle, rotary, DIP, push-button, rocker, membrane, … the list just goes on and on. Each of those switch types has a set of unique characteristics to differentiate it from others. Characteristics like what action flips the switch, or how many circuits the switch can control. You can check the different types of switches we having with us.Transistors can be regarded as a type of switch, as can many electronic components. They are used in a variety of circuits and you will find that it is rare that a circuit built/available in school Technology Department/ Laboratory does not contain at least one transistor. Even the things you used in your daily life, i.e mobile, tv, computers, etc all comes with tons of transistors built into it, transistors are central to electronics and there are two main types; NPN and PNP. Most circuits tend to use NPN. There are hundreds of transistors which work at different voltages but all of them fall into these two categories.We had added detailed tutorial on ” Getting started with switch, transistors and buzzer on breadboard “ , so that you will clearly understand the basics of switches, transistors and buzzer.

Pi Wedge

Its time to expand your GPIO pins from the Raspberry pi and made it accessible for Breadboarding. The preassembled 40-pin Pi Wedge will let your Pi pins broken out to a breadboard so that they can easily be used. The Sparkfun has already added a detailed hookup guide on their website, we will recommend you to refer this tutorial to understand pi-Wedge better.

Physical Computing on Raspberry Pi

The Raspberry Pi learning resource is provided for free by the Raspberry Pi Foundation under a Creative Commons licence, which we are able to access from their website, you can find the resources here, We have provided all the items in the Electronics Starter Kit to get started with mentioned tutorial, all you need to do is follow the steps mentioned in the getting started tutorial to understand the basic principles  of interfacing individual items. please go through this guide on “Getting Started with Physical Computing on Raspberry Pi “

Scratch

Scratch is a visual programming tool which allows the user to create animations and games with a drag-and-drop interface. It allows you to create your own computer games, interactive stories, and animations using some programming techniques without actually having to write code. This resource will help get you started with the basics of Scratch. The Raspberry Pi learning resource is provided for free by the Raspberry Pi Foundation under a Creative Commons licence, which we are able to access from their website, you can find the resources here, please go through “Getting Started with Scratch on Raspberry Pi Tutorial” to understand the various features and application of the Scratch tool.

Blinking LED

Since you have already seen some basic programming in the getting started section, we are adding one more advancement in the LED circuit and code here, we will recommend you to build the following circuit in your breadboard:

Blinking LED Circuit

To begin with, we will recommend you to open the IDLE from the following path: Menu -> Programming -> IDLE 3/Python 3 and you will find the Scratch in the Same path as well:  Menu -> Programming -> Scratch.We had added the python code and Scratch Project in the following link, you can save/download the file in your system, click on the respective icon to open/download the file.

You can refer to scratch program in the image below:

LED Blinking

Switch

In this step you have to add switch connection to the LED connections you made in the previous step. Follow the circuit shown below:

Switch Connection

Now refer the Scratch and Python Code to get it working

You can refer the Scratch program in the blow image:

Contro LED Using Switch/Sensor

Capacitive Touch

The capacitve touch module we providing in the Kit works as momentary switch in default mode, but if need you can solder the jumper to the pads or add some conductive tape to the pads to change the mode of operation from momentary to toggle. The Capapcitive touch module is capable to sense the human touch, even it can sense the body within nearby range to the pads thus allowing you to place the pads under thin cardboards/paper/plastic, you can add copper tape to it to extend the capacitive touch area as your wish. These tiny boards are nice addon to your project. Refer the image below for the connection diagram:

Capacitive Touch Board description

The board works well with 3.3v and 5v Systems, thus giving you the flexibility to use it straight away, these boards comes with onboard LED for the indication, thus you can use it as an independent product without any need of  Microcontroller or Microprocessor. Now, refer the breadboard connection for the Capacitive touch board and the LED:

Capapcitive Touch and LED Connection with Raspberry Pi

Since we had replaced the tactile switch with Capacitive touch module in this circuit and we let the LED stay as it is like in the previous steps, thus the code which we used to control LED with tactile switch will work for this module as well.

Note: We had used GPIO pin 24 to connect Signal pin of the Capacitive touch module thus the previous code will work for this case as well, but if you had used some other pins for this module, make sure to change the pin numbering in the code as well.

If you are using the Capacitve module in Toggle Mode, try out the following code to understand the difference:

Transistor and Buzzer

Till now, you have seen the LED indication in the output side, now its time to add some sound to the circuit, since you had already worked with ” Getting started with switch, transistors and buzzer on breadboard “  tutorial, this step is going to be easy. Refer the modified breadboard connection for the circuit.

Transistor, Buzzer and Switch Interface with Raspberry Pi

We are not adding any specific code to this section because the circuit is connected to work with all the three codes described above, so we will recommend you to run all the three codes again for the above circuit, try to add and change the delay in the code, so that you can hear the variation in the output.Since you already understood the basics of various components and its interfacing and programming in scratch and python, we are giving you challenge to breadboard RGB LED we provided in the Kit and write your own Python and Scratch code for the same, to made it glow for different combination of colors.

Let us know your feedback on this and we are happy to help you, if you found any issue or difficulty in any circuit or have any queries, please do let us know.

References:

• Tutorial: How to Breadboard LED
• Tutorial: Getting started with switch, transistors and buzzer on breadboard
• Sparkfun Tutorials
• Buy Switches Online
• Buy Transistors Online
• Raspberry Pi Learning Resources

This hookup guide is not only limited to the MOSFET breakout board, here you can learn basics of MOSFET, so that you can build your own circuit in a breadboard/ Protoboard with components we are providing or use if you have some with you. Check below the contents we covered in this tutorial:

• MOSFET BASICS

• Hardware Needed

• MOSFET Breakout PCB Introduction

• PCB SilkScreen

• Gate Control Circuit Schematics

• Jumper Settings

• PCB Assembly

• Heatsink Assmebly

• References

MOSFET BASICS

Most of you have heard of BJT and MOSFET but still you have doubts regrading MOSFET, here we are covering some basics of MOSFET before going to the breakout board details. MOSFET stands for “metal-oxide semiconductor field-effect transistor”. It is a special type of field-effect transistor (FET). Its gate input is electrically insulated from the main current carrying channel and is therefore also called as an “Insulated Gate Field Effect Transistor” or “IGFET”. Unlike BJT which is ‘current controlled’, the MOSFET is a voltage controlled device. The MOSFET has “gate“, “Drain” and “Source”  terminals instead of a “base”, “collector”, and “emitter” terminals in a bipolar transistor. By applying voltage at the gate, it generates an electrical field to control the current flow through the channel between drain and source, and there is no current flow from the gate into the MOSFET. Unlike the BJT, the FET is a unipolar device since it functions with the conduction of electrons alone for the N-channel type or on holes alone for a P-channel type.

Hope now things are little clear to you now, but this is not enough, so we had covered types of MOSFET as well, refer the types below:

• N-Channel (NMOS) or P-Channel (PMOS)
• Enhancement or Depletion mode

N-Channel – For an N-Channel MOSFET, the source is connected to ground. To turn the MOSFET on, we need to raise the voltage on the gate. To turn it off we need to connect the gate to ground.

P-Channel – The source is connected to the power rail (Vcc). In order to allow current to flow the Gate needs to be pulled to ground. To turn it off the gate needs to be pulled to Vcc.

Depletion Mode – It requires the Gate-Source voltage ( Vgs ) applied to switch the device “OFF”.

Enhancement Mode – The transistor requires a Gate-Source voltage ( Vgs ) applied to switch the device “ON”.

Despite the variety, the most commonly used type is N-channel enhancement mode. There are also “Logic-Level” and “Normal MOSFET”, but the only difference is the Gate-Source potential level required to drive the MOSFET. Refer the symbols in the diagram below to distinguish the types of MOSFET.

MOSFET TYPES

Now consider the following points while connecting the load/Heatsink to the MOSFET:

• Because load  has resistance, which is basically a resistor. For N-channel MOSFET put the load at the Drain side and Source is usually connected to GND. If load is connected at the source side, the Vgs will needs to be higher in order to switch the MOSFET, or there will be insufficient current flow between source and drain than expected
• For P-Channel MOSFET put the load at the source side and drain is usually connected to GND.
• Typically the heat sink on the back of a MOSFET is connected to the Drain! If you mount multiple MOSFETs on a heat sink, they must be electrically isolated from the heat sink! It’s good practice to isolate regardless in case the heat sink is bolted to a grounding frame.

Hardware Needed:

MOSFET Breakout Board	N Channel MOSFET (IRF1404)	Heatsink -Multiwatt Package
1KΩ Resistor	Screw Terminal- 2pin (5mm)	Male Header 40 x 1

MOSFET Breakout PCB Introduction:

This basic is enough for now, to getting started with MOSFET. There are many more things which you can do with MOSFET, we did not covered all the things in details here, but we will recommend you to start using MOSFET in most of the circuits to understand its uses in various applications, only practice makes man perfect, so this is what we are expecting from you that you will build something really cool projects using MOSFET. Now its time to go in details of MOSFET breakout board. Refer the board shown in the Image below:

MOSFET BREAKOUT PCB

PCB SilkScreen:

Now if you notice, then you can see the silkscreen at the bottom and the top will distinguish between P Channel side and N channel Side. You only need to solder the parts which are dedicated for that specific channel, i.e if you are willing to use just N channel Enhancement type MOSFET in your project, then all you need to do is to solder the parts needed only for N channel, which you can easily distinguish by referring the silkscreen. We had highlighted the TOP side silkscreen in the following image to distinguish between the two channel side.

N Channel / P Channel

You can refer the following image to see which resistors refer to which channel, this you can easily distinguish, if you refer the bottom silkscreen.

N Channel/ P Channel Resistors

Gate Control Circuit Schematics:

We had added the Pull_Up / Pull_Down Resistor for the Gate, this feature is disabled by default, but if you need you can use this feature in your circuit by enabling the jumper J1/J2. Refer the below Schematics for better idea of the circuit.

Gate Circuit Schematics

You can see in the following images we had highlighted the pull_up/ pull_down resistors.

Gate Control Resistors

Jumper Settings:

These Pull-Up/Down Resistors (R_U/D) is disabled by default and can be enabled by adding solder to the Jumper Pads J1 for P-Channel and Jumper Pads J2 for N-Channel, the Vcc and Ground side is indicated in the Silkscreen. Its a 2-Way Jumper thus center pad is the main path and you need to apply solder either to “+” or “-“, so make sure to solder only required logic for each jumper, i.e either Vcc or ground. In case you need to disable this feature from the circuit, just remove the solder from the pads you applied. You can see the J1 and J2 Jumper in the following image and the + and – indication against its pad.

Jumper Pads

Note: Do not Solder all the three pads of the jumper together, this will create a short between Vcc and GND.

Refer the below table for jumper selection chart:

You can ignore these R_U/D and R1_U/D resistor in the breakout board, if you don’t need pull_up/Down Feature. Now if you notice the Gate schematics you can see that the control signal is passed via Gate Resistor, so you need to solder this in your breakout PCB to get the circuit working, if you don’t want any Gate resistors, you can solder the 0Ω Resistor in the R_G / R1_G. We had Provided some standard values of resistors with this breakout board, so you don’t need to worry much about it, all you need to do is, to solder the resistors as per your requirement. Refer the below image for the Gate resistors slot in the Breakout board.

Gate current limit

Note: MOSFET will not work if R_G / R1_G  Gate Resistor is left open, atleast you must solder 0Ω Resistor or short the slot with solder/Wire.

PCB Assembly:

The Drain and  Source pins are indicated clearly on the TOP/BOTTOM Silkscreen, this can be accessed either with screw terminal or with male/female Headers, you can solder whichever you need. You need to solder three pin header for Gate, Gnd, Vcc pins as well, so as to control the MOSFET from microcontroller or any other circuit. Make sure to use the Gate Control header of the same channel as that of MOSFET. Refer the legend and the diagram below for the  N- Channel MOSFET assembly:

Legend

N Channel MOSFET Assembly

Heatsink Assmebly:

The board supports one N Channel and one P-Channel MOSFET at the same time, since both channels have its own sets of resistors, headers and screw terminal slot, make sure that all the things are properly connected. For the high current application your MOSFET will heat up like crazy, thus you need to add heatsink to provide cooling to the MOSFET, we had provided Heatsink Slot to be soldered on board for both type of MOSFET, refer the following image on how to use heatsink with MOSFET:

Heatsink Multiwatt

N Channel MOSFET with Heatsink

The P Channel also supports Heatsink. If you are using Heatsink with N Channel  MOSFET then it is not possible to use P Channel MOSFET or vice versa. The Heatsink is not provided with the MOSFET Breakout PCB, you need to buy it separately if needed. If you are facing any issue or difficulty with the PCB, do let us know, our team will help you with all the issue, we are happy to hear from you, do let us know your feedback.

References:

• MOSFET types Image Source:  Electronics Tutorials
• Heatsink Image Source: Sparkfun

Ardublockly

Ardublockly is a visual programming language that is based on Google’s Blockly. Being a visual programming language you don’t need to worry about remembering syntaxes or missing semicolons. The Arduino code is generated when the blocks are connected to perform an action. Ardublockly also displays the actual C code that is being uploaded making it easier to understand what goes on in the background.
 

Installing & Configuring Ardublockly

Get the latest version of Ardublockly from its github page. Do ensure that you have the latest Arduino IDE installed as well, check the Arduino guide for more info on how to install Arduino.
Installing on Windows

1. Extract Ardublockly – Once you have downloaded the latest version of Ardublockly, extract it to a location of your choosing.
2. Run Ardublockly – In the Ardublockly folder run the ardublockly_run.bat. This will run Ardublockly and create the ServerCompilerSettings.ini file that we need to modify to get Ardublockly working. Once Ardublockly has successfully started you should see the Ardublockly homescreen.
   

   Ardublockly IDE

3. Close Ardublockly – Now that the ServerCompilerSettings.ini has been created, we can close Ardublockly
4. Open ServerCompilerSettings.ini file using Wordpad – The ServerCompilerSettings.ini file needs to be edited to configure the location of arduino_debug.exe
   Note: Open the file using pretty much any text editor other than notepad as notepad does not recognize the line breaks properly
5. Add location of arduino_debug.exe –   The location of arduino_debug.exe if installed via the Arduino installer, will be located at C:\Program Files (x86)\Arduino\arduino_debug.exe
   

   ServerCompilerSettings.ini configured using wordpad

6. Run Ardublockly – To test whether it has been configured properly, run ardublockly_run.bat and open the preferences ( Edit → Preferences) it should show a window like this
   

   Ardublockly Preferences

7. Select Board & Port – Next select the board that is being used, in our case it is the UNO. The available serial port will be shown only if the Arduino is connected.
8. Test Configuration – To ensure everything is all set and done click on the verify button

Ardublockly Verify

Verify Successfully

• If all goes well the Successfully Verified Sketch will be displayed, this may take 20-30 seconds on some machines.

Blinking An LED

• The first step should be to add the Arduino Run First/Arduino Loop Forever block although this is not necessary it will help keep your code clean. It can be found under the functions category

 


• This block lets define what instructions need to be run first and what needs to run forever. Most instructions will come under the latter.
• Next involves setting the digital pin onto which the LED is connected as either HIGH (ON) or LOW (OFF), this block can be found under the Input/Output category

 


• The on board LED is connected to pin 13, set the pin# to 13 to be able to turn ON the LED. Next comes the delay this will ensure that the pin stays in the HIGH (ON) state for a set period of time. This can be found under the Time category. The time is set in milliseconds, 1 second = 1000 milliseconds.

 


• These 2 steps needs to be repeated again but in the LOW state to turn off the LED. The final code will be as follows.

Blink Code

• Click the upload button to push the code to the Arduino.

Upload Button (Center Button)

• If all goes well, the LED should start blinking now.

Successful Upload

Good to see that lots of people are interested and looking forward for Raspberry pi, to have the feel of old gaming experience. We already wrote one blog on Retro Gaming machine using Raspberry pi, we mentioned there how to download RetroPie Image and ROM and Install it in your system. We will recommend you to go through Retro Gaming machine using Raspberry pi Blog

This blog is targeted towards people who might not want Raspberry pi to be dedicated just for Retro Gaming Purpose or whom already have our Raspberry Pi Gaming Kit or whom having Raspberry loaded with Raspbian. Here we mentioned steps on how to install RetroPie on a Raspberry pi running Raspbian. This setup will give you flexibility to use any one system(Raspbian or RetroPie) as per their need, i.e they can run RetroPie without uninstalling Raspbian and choose between any one at a time to work with. We will show you how to set RetroPie EmulationStation as default environment and from their if you want you can skip the RetroPie and go to either terminal or Raspbian desktop environment.

To start with, we will recommend you to have our Raspberry Pi Gaming Kit ready with you, its comes with SD Card preinstalled with latest Raspbian on it. Note: If you aren’t comfortable with the terminal you would be wise to just use the RetroPie SD image as described in this Retro Gaming machine using Raspberry pi Blog. Follow the steps mentioned to get it working.

1. Download RetroPie Setup script
2. Download and Install Putty to run Command via computer
3. Set EmulationStation as default boot option (video)
4. Download ROM
5. Install ROM
6. Configure Gamepad
7. References

1)    Open the command terminal, refer the following image if you don’t have idea where is it:

2)   Download RetroPie Setup Script: 

cd
git clone --depth=1 https://github.com/RetroPie/RetroPie-Setup.git

 

All you need to do is copy the mentioned command line by line and paste it(mouse right click) to the terminal. If you are wondering how to copy paste this, then you can either open this blog in the Raspberry pi browser or It is recommended to use putty on your computer to access the Raspberry Pi terminal.

Download and Install Putty to run Command via computer:

Download Putty from here and install it, then you need to enter you Raspberry Pi IP address in the space provided, refer the following image for the same:

Raspberry Pi IP address can be found out by running the ifconfig Command in your LX terminal. Make Sure that your Raspberry Pi is connected to Wifi or ethernet before doing this step.

3)    Once the Script is downloaded you need to execute the script as follows:

cd RetroPie-Setup
chmod +x retropie_setup.sh
sudo ./retropie_setup.sh


4)    Make sure to run command line by line as shown, refer the video shown below on how to install the RetroPie

5)   Set EmulationStation as default boot option (video):  It will take some time to install the RetroPie on Raspbian, you need to wait till then, once done, the last step you need to do is to run the script again and set EmulationStation as default in the boot option, refer the video below for the same:

6)    Once the above step is done, you can see that after the computer reboots, it will open the EmulationStation by default, if you want to access command terminal, you need to press F4 on you keyboard to exit the EmulationStation, you can type emulationstation in the command terminal to open EmulationStation back again. To open pixel desktop you need to run startx command in the terminal, it will load pixel environment for you.

Note: You cannot run EmulationStation and the LXDE/ Pixel Environment at the same time so you need to reboot your system to turn on your EmulationStation.

7)    If you are all done till previous point, now all you need to add is ROM to your system, due to the nature/complexity of Copyright/Intellectual Property Rights Law, which differs significantly from Country to Country, ROMs cannot be provided with RetroPie and must be provided by the user. You should only have ROMs of games that you own.Refer this link to see how to download ROM and Install ROM

8)    Configure Gamepad: Once you added the ROM, its time to configure your gamepad, to do so open the EmulationStation Menu( refer the below shown Image)

Select: retroPie menu -> Input options.

9)    Make Sure to connect your game pad before selecting Input options from the Menu. Once selected refer the below key map to configure your gamepad, all you need to do is to press the corresponding key for the shown input option.

Once done, the settings will be saved permanently  in your system, incase any mistake happened, you can reconfigure your gamepad anytime. Refer this link, if you are planning to add some other gamepad to your raspberry pi, once done you are ready to control your EmulationStation and play games using your gamepad.

Note: Only one input is supported for single player games, thus if you had connected multiple inputs like keyboard and gamepad, make sure to disconnect whichever not needed and connect only one.

Do let us know if you are facing any issue with any step, our team will get back to you, to help with installation.

References:

• Buy Raspberry Pi Compatible Gamepad
• Updating RetroPie
• RetroArch Configuration
• FAQ

The particle photon provides one of the best IoT experience in the market, its out of the box experience is unparalleled. Here we will be talking about the steps required to get started with the Particle Photon.

Hardware Required:

	Particle Photon w/ Headers
	microUSB Cable

Manually upgrading to the latest firmware:

The Particle Photon may not come with the latest firmware, the firmware is automatically upgraded to the latest version when a program is uploaded. Alternatively, the firmware can also be upgraded to the latest version using the Particle Firmware Manager app. You can get the latest version from Firmware Releases page

Once downloaded, run the application as administrator this will automatically install the drivers first and will later ask to connect the board.

Once the drivers are installed, connect the Particle Photon and click on Update to X.X.X where X.X.X is the firmware version.

Connecting the Particle Photon to the WiFi using the Particle App

1. The easiest way to configure the Particle Photon is using the Particle App, there are Android and iOS versions available.
2. Once the board is booted up and in setup mode the on board RGB Led will start blinking blue.
3. Click on setup a photon and choose the WiFi AP corresponding to Photon-XXXX where XXXX varies from board to board. Once connected select your WiFi and enter the password.
4. The tinker code helps you configure the various GPIO pins on the Photon through the mobile app. If the board is flashed with a non-Tinker code, it can be re-flashed though the app itself. The on-board LED is connected to D7

Programming the Particle Photon

Particle offers 3 options to program the Particle Photon.

• Online
• Semi-offline
• Offline

In this tutorial we will be covering the Online and the Semi-offline method

Programming the Particle Photon Online

Particle has a great online IDE that can be used for pushing code onto the Particle Photon.

	Flash the code on to the Particle Photon
	Verify the code of errors
	Save current code
	Show/Hide the side bar
	List of libraries
	View the docs
	List of devices
	Open the Particle Dashboard that will list all your devices and products
	Basics settings for Particle Account

Step 1: Get the Code ready

The first step would be to create an app, for the tutorial we will be using the blink an LED app. Once the code is typed out and ready to be flashed, the board that needs to be flashed needs to be selected.

Step 2: Select the device

The device to be flashed can be selected from the list of devices tab. Here you can also select the firmware that is to be used.

Step 3: Flashing the code

Flashing the code is as simple as clicking on the flash button. The first time uploading the code might take longer as the firmware will need be upgraded, this process is denoted by the magenta color on the RGB Led

Programming the Particle Photon using the IDE

The Particle IDE offers a local solution to coding on the Particle Photon, the IDE allows you to code locally but still requires an internet connection to be able to compile the code and to push it to the board.

In order to be able to select the board that needs to be programmed, the IDE needs access to your particle account. This can be done through the Particle menu, Particle → Login to Particle Cloud
The device can be selected from Particle → Select Device

In order to get started, we need to create a project folder which will hold the code. Once done add the project folder to the Particle IDE. This will show in the side bar

All of the files for the project will be shown in the sidebar. Any library that is to be included in the code must be added to this folder , all added libraries will show up under this.

Once the code is ready to be uploaded, click on flash. The status will display success once uploaded.