Robotics Basics.

Making A circuit in TinkerCad.

Creating a basic circuit.(sir Anith Taught me)

• Lighting an LED. To lit a bulb or a LED, one important required thing is Power. Tinkercad provides six types of power supply. • Lighting LED with power supply.

Figure 1

But before that Students should learn about two types of electrical circuit. Click Here .

So in the above image, the LED id directly connected battery: if this circuit is created in TinkerCad. and if you start the simulation. The exclaimation mark represents that excessive amount of current is flowing through the LED.

Therefore, to limit the flow of current we can make use of electrical passive device called Resistor.

Figure 2

Resistor offers resistance to the flow of current through the resistor. - Resistance: Resistance is a measure of the opposition to current flow in an electrical circuit. - Resistance is measured in ohms, symbolized by the Greek letter omega (Ω).

The image below can help visulize the relation between resistance, current and voltage.

Therefore, the flow of current can be easily connected with the flow of water. Where the pressure of the waterflow can be linked with the voltage in the circuit, Resistance with the small size of cross section to limit the flow of water, which can be linked with the flow of current in a circuit.

Figure 3

Before using the resistor, we also have to understand the measuring value of a resistor. - Every Resistor has a color code that defines the level of resistance it can provide to the flow of current. To check a video click here.

Figure 4

• Then to confirm what color code of resistor to be assign, We have to follow Ohm's Law.

Ohm's Law

Ohm’s law states that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperature remain constant. - V = IR - I = Current - V = Voltage - R = Resistance

So For LED's, 20mA is best amount of current across the LED. - Therefore to find the value of resistance required is: - let Current (I) = 20mA - Voltage (V) = 3V

Using

V = IR

Which can be also written as

R = V/I

Therefore; $$ R = \frac{3V}{20x10^{-3} A} $$ - R = 150 Ω.

Adding R = 150 Ω in series and performint simulation

Figure 1: Aesthetic Centre

Adding a Switch in the circuit.

• A switch can be used to turn on or turn off a circuit. It can used to make a circuit open (off) or closed (on).
• In this circuit we will be using a slide switch. A slide switch has two terminal and a common terminal. The common terminal will be connected to the LED through a resistor. The other two terminal can be used to complete or break the circuit.

The image below shows the use of switch to control the glow of the LED.

Figure 1: Aesthetic Centre

• Basically for the LED to glow the circuit should be completed (i.e the two end ot the LED terminal should be connected to the positive and negative terminal of the power)
• When the switch is off, the LED is disconnected from power i.e both side is connected to the negative terminal of the battery.
• When the switch is on, the circuit is completed and the LED glows.

Schematic.

ThinkerCad can also be used to generate schematic from the design we make.

What is Schematic?

A schematic, or schematic diagram, is a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures.

Figure

The schematic shown above is symbolic representation of the circuit we have designed earlier. Schematic can be used to learn the symbols of the components used our design. - The numbered symbols are: 1. Resistor. 2. LED 3. Switch 4. Battery.

Introduction To Arduino.

Figure

What is Arduino?

Arduino is an open-source hardware and software company, project, and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices.

To understand more about arduino, Click Here.

Arduino in TinkerCad.

Tinkercad provides various other controllor but we would be focusing more on Arduino UNO Board. - Arduino is available is various range of board version such as Arduino UNO, Arduino Nano, Arduino Mega etc.

To start programming arduino: 1. First add the arduino Board to the design from the component list. 2. Before that lets understand the different views, we can select in the tinkercad platform.

Figure

On the top right corner, we can select the views such as:

  1. Circuit view: Where we can make design.
  2. Schematic view: Whatever circuit is designed in the circuit view can be represented with components symbols.
  3. Component List: All the components added in the circuit will be listed in this view.
  4. Code: This will let the user write codes to perform simulation. Options for Block and text programming are available.
  5. Start Simulation: Whenever a design is ready, we can test the design by clicking the start simulation button.
  6. Send To: enables users to share their work.

Blinking LED with Arduino.

LED

As we have learned, Arduino has Digital and analoge pins. One of the digital pin (i.e Pin 13) has a builtin LED marked red in the picture above.

• Therefore the key point to remember is that we will be using pin number 13 to controll the builtin LED.

The block program to blink an LED on and off with deslay of 1 second each is.

Block Code

• First block: Will send a HIGH signal to the builtin LED pin (i.e pin number 13).
• Second block: The first block will be executed and and it will wait for one second before it executes the next block.
• Third block: Similar to first block, now it will send a LOW signal to the builtin LED pin.
• Fourth Block: Wait for one second.

This block of code will repeat multiple times, until the simulation is stopped.

Another Interesting feature of Tinkercad is that it will generate a text program, which can be directly uploaded to the real arduino board.

When ever a block program is created, it will simultaneously generate a text program.

The text program for the blinking LED is given Below:

Text Code

In text programming, by default arduino code will have a void setup method and void loop method. The difference between the block code and text code is mostly the void setup() :

• The setup method is executed on once when the a system or a code is initiated.
• Most of defining and initializing parameter work is done in this method.
• The parameter/pin defined here is the LED_BUILTIN (i.e pin number 13) and the function of that pin is to give output.
• In block code, defining and initializing work is handled by the platform.

Void loop():

This method determines the kind of work and processes the arduino will consider. Once the setup method is completly executed. Then it will directly jump to the loop methode. - If you compare the line of code here and block code above, both express the same type of instructions. Just expressed in text syntax.

Blinking external LED.

Till here, it has been mentioned that the builtin LED is connected to pin number 13. So we will be using the same code and will only make changes to the circuit.

• To do that, we have learned that to power up a LED we need to make a complete circuit. That is connect anode of LED to positive terminal (here we can use pin 13 since all the instruction are executed on pin 13) of through a current limiting resistor and cathode must be connected to the negative terminal (Ground/GND in arduino).

Led Test

Working with Servo Motor.

What is a servo motor? - Servo motor is a rotary actuator, which means that we can adjust the output shaft to a specific angle. And we can provide the angle through program code of other input devices.

Servo Label

1. Case
2. Mounting taps
3. Output shaft
4. Servo Horns
5. Cable
6. Connector

Servo Motor comes in with 3 pins for power and signal.

Figure 1: Aesthetic Centre

1. Power (RED): Connects to 5V.
2. Ground (Brown): Connects to ground.
3. Signl (Orange): Connects to any of the arduino pin, which can generate pulses.

To know more about servo motors, click here.

Connecting Servo circuit.

From the components list, add: - Micro Servo and - Arduino Uno R3 : our microntrollor.

Servo's can only be connected with those pins which are capable to generation pulse with modulation. Those pins can be identified from the arduion board.

PWM pins

Take this in mind disign your own circuit understanding the basic connection rules learned during previous circuits. Start by adding the components on your design space.

Components

Click on the terminal of servo and connect it to the Arduino as shown in the picture below.

Servo Circuit

To change the color of the connecting wires, on the top left cornor those options are available.

Servo program.

Servo Code

From the block collection, similar to the code from blinking LED, replace the LED HIGH block with SERVO ROTATE block and insert the pin number and angles.

Finally click on start simulation to view the servo simulation.