Solar Powered Tracker and Charging

DeviceSponsored by: Progress Energy

Group 12: Diijon Gumbs James Lillie

Kaniel Martin

Goals and Objectives

To build a mobile device to track sunlight and use it for conversion to energy for charging batteries (car and normal sized battery).

Needs to be cost efficient Needs to be able withstand different types of weather

conditions. Track the most amount of sunlight through actuation.

Specifications and Requirements Solar panels

◦ Weather Resistant◦ Produce 40 W of power◦ Have 50% efficiency

Frame◦ Weather Resistant◦ 360 degree horizontal rotation◦ 120 degrees vertical rotation◦ Total Weight No larger than 30 pounds◦ Rotating Frame No larger than 15 pounds◦ Dissipate heat

Voltage Regulator◦ Used to charge 5-12 Volt batteries◦ Have about 85% power efficiency

Stepper Motors◦ Use 0.5-1.5 amps◦ Can freely move 5 pounds

Specifications and Requirements Continued Microcontroller

◦ Can at least receive 8 inputs◦ Has at least 10 output ports◦ Can handle both analog and digital I/O◦ Has Pulse Width Modulation

Batteries◦ Rechargeable ◦ 15-20V

Voltage Sensors◦ Can read voltage from 0.1 - 50V

Display◦ Can display our four output criteria◦ Can support at least a 5V input

Servo Motor◦ Operates on 5V◦ 100 degree turning radius

Block Diagram of Design

Photo SensorsVoltage Sensors Microcontroller

LCD Display

Motor Controller Motors

Solar Panels Regulator Batteries

Solar Panels, Microcontroller, Voltage

Regulator, BatteriesKaniel Martin

Arduino Mega 2560 5V operating voltage 6-20V input 54 digital I/O pins 14 PWM outputs 16 analog Input Pins 256 KB Flash Memory 8 KB SRAM 16 MHz Clock Speed

BSP10 Solar PanelCharacteristics

Dimensions

Weight

Typical Data at STC (Standard Test Conditions)

16.5in10.7in1.31in

4.2 lbs

Rated Power Pr 10 WPeak Power Pmpp 10 WPeak Power Voltage

Vmpp 17.3 V

Peak Power Current

Impp .58A

Open Circuit Voltage

Voc 21.3 V

Short Circuit Current

Isc .66 A

Solar Panel Diagram

LM358 Voltage Regulator

• 35 Max Voltage

Batteries 19V Battery used to

power the board, and LCD

16 V Battery used to power the motors

12 V and AA Batteries used for charging

Alkaline Batteries Rechargeable 80% efficiency Up to 50 times the lifetime of the non-rechargeable variety

50 – 500 cycles Easy to predict charge Non Rechargeable 95% efficiency Less than 5 year lifespan Harmful to the environment Cheap!!

Nickel Cadmium 70%-90% efficient Lasts up to 5 years 1500 cycles Charge rate of C/10 Lose charge quickly Toxic! Average Cost

Lithium Ion High initial voltage Have a high charge level Become very hot Excellent performance initially but declines

with time. Very expensive 1200 cycles 2-3 years 5%- 10% discharge rate

Lead Acid Batteries 70% – 80% efficient Lasts 5-8 years 500-800 cycles Charge Rate of C/8 Low Cost Easily Recycled Large Array of sizes and voltage levels

Deciding on whether to use one battery to power the whole project, or to designate a battery for each component.

How to deal with the major fluxuations in voltage from sunlight to the circuit design and overall efficiency.

Not only learning more about the different programming codes needed for our design, but the integration of them as well.

Problems

LCD Display, Solar Sensors, Voltage

SensorsDiijon Gumbs

LCD Display We need a display to show the proper

criteria in relation to the project. These criteria include: power efficiency,

current, voltage, and battery life. This criteria must be produced on the

display through a percentage or as a unit of measurement.

Memory storage will be an important element in determining what type of display chosen.

Hitachi HD44780 Display Usage of ASCII symbols through binary to read to the

display. Cheap in cost Dimensions: 98.0x60.0x15.0 mm 16 ports to be used Components

◦ 20 characters by 4 line display◦ White characters with a blue background and backlight

display◦ 7 pin GPIO pin usage for 4-bit mode and 11 pin GPIO pin

usage for 8-bit mode ◦ 5V DC operation ◦ Wide viewing angle and high contrast◦ +5V DC LED backlight

HD44780 LCD Display

HD44780 LCD Display For this project we will be only using a

limited amount of ports and not all of them for our displaying of data.

Will be employing 4-bit mode operation 16-bit male header needs to be put on

through a soldering process before being used with breadboard.

Viewing our results on LCD Display Backlight will be incorporated when

weather conditions hinder viewing ability. We need to also change the contrast by

using a 10k potentiometer connected to the contrast port (port 3).

Circuit Schematic

Solar Sensing Sense how much sunlight is being shone. Usually most solar sensing is used through

the use of photodiodes or photoresistors. Must be used through devising a circuit.

Photoresistors Same as photodiodes except they don’t

react to sunlight well. Use simple voltage divider circuit to get

readings. Best decision when it comes to our

project. Looked into the VT400 Perkin Elmer series. Three main types: Indium Antimonide,

Silicon, and Cadmium Sulfide.

Photoresistors Continued Our choice was the Cadmium Sulfide type photoresistor from

Adafruit (light: 5-10K; dark: 200K). Will be using with a 1K resistor to realize voltage reading circuit

with the 5V input connected to microcontroller port. Other portion will be connected to analog pin on arduino board.

Can use a 10K resistor instead, but it will hurt our readings at bright levels of light.

Voltage Sensing Looked into many types of panel sensors. One approach: we were looking into using a

voltmeter to incorporate into our finalized circuit through the soldering of the contacts onto a finalized circuit.

Final decision: ◦ Simple voltage divider circuit to read the voltage

as we used for the light sensing. ◦ similar to photoresistor circuit

Circuit Implementation Using a breadboard kit to conglomerate LCD

Display, voltage dividers with the photoresistors will make up our circuit.

Problems LCD Display

◦ Have to learn more about the use of the codes for the ASCII characters (display).

◦ Looking into how to incorporate display with the main microcontroller to show the accuracy of the results.

Solar Sensor (Photoresistor)◦ Finding out if the resistor value chosen will indeed

show the brightness of the light or miscalculate the results.

Voltage Sensor◦ How to make sure the readings were read precisely

with accuracy (noise).

Frame, Motors, & Motor Controllers

James Lillie

Required to house electrical components as well as allow mounting locations for solar panels

Allows two Panels to be mounted one facing up one facing down

Has reflective surface for downward facing solar panel

Allows for a locking mechanisms Water Resistant

Frame

360 Degrees of Horizontal Rotation 120 Degrees of Vertical Rotation DC Motors, Stepper Motors, Servos, Linear

Actuators Gear Reducing Ratio for higher torque Accurate Rotational Speed

Panel Rotation

Frame Side View

Frame Top View

Sunlight Sensor Design

Servo Motor Used as a locking mechanism Can operate off of the Arduino Mega 2560 Can operate on 5V power source Rotation Range of at least 60 degrees

Servo Motor Comparison

Servo Motor Range Operating Voltage

Price

Hitec HS-311 Servo Standard

90 degrees 4.8-6V $8.99

Hitec HS-322HD standard hobby servo

100-200 degrees

4.8-6V $9.99

Hitec HS-422 standard hobby servo

60-200 degrees

4.8-6V $12.99

Hitec 322 Standard Servo MotorTorque: 41.66 -

51.38 oz*in Voltage: 4.8V - 6VTurning Range: 100-

200 Degrees

Needed to turn frame. Low power consumption (less than 2amps) High Torque Able to output enough force to rotate a

static 15lb disk

Stepper Motor

Stepper Motor Comparison

Stepper Motor

Holding Torque Torque

Current Rating Price

NEMA-23 Bipolar 76mm Stepper

12.5 Kg-cm 2.2A $31.20

M-200-ROB-09238

2.4kg*cm 0.28-0.33A $14.95

NEMA-17 Bipolar 5.18:1 Planetary Gearbox

30 Kg-cm 2.5A $51.65

Bipolar Stepper Motor Step Angle: 1.8 degrees 2 Phase Rated Voltage 12-15.4

Volts Rated Current .28-.33

Amps Holding Torque

2.4kg*cm Detent Torque 120g*cm

Needed to drive two stepper motors Voltage rating of at least 16 volts Easily interfaced with micro-controller Has quarter, half, and full step capabilites Has Sleep Mode for Power Saving

Motor Controller

Motor Controller Comparison

Stepper Motor Controller

Current Supply

Voltage Supply

Number Of Motors Driven

Price

EasyDriver v4

150-750mA

7-30V 1 $14.95

L298 2A 5-46V 1 $23.50

Eazy Stepper V4 Drives one Bipolar

Stepper Motor Compatible with

4,6,or 8 wire Motors

Power Supply Range of 7-30 Volts

Adjustable Current From 0.15-0.75 Amps

Sleep Mode

Motor Controller Circuit

Frame Rotating Location Frame cannot rotate more than 360

degrees to stop the tangling of wires.

Problems

Progress Chart

Total Progress

Testing

Parts Built

Parts Acquired

Design

Research

0 10 20 30 40 50 60 70 80 90 100

Solar Power Tracking Device

Components PricesMicrocontroller $72,00Motor Controller x2 $35.50Stepper Motor x2 $33.50LCD Display $25.00Photoresistors $12.00Circuit Board Kit $26.00Batteries TBD ~ $60.00Solar Panels TBD ~ $240.00Misc. (resistors, wires, etc.) TBD ~ $20.00Frame Materials TBD ~ $100.00Estimated Total (subject to change) $626.00

Budget