Section 1:
For Homework 5 we again split the project up between group members. Alex has been working on the realistic constraints as well as the professional and ethical responsibilities of the system. Carolina and Joe have been working on the programming aspect of this project along with sample programs that will work with the chosen hardware. Steve is gaining knowledge on the different varieties of Arduino boards and which, if possible, can best suit our recognized needs. Each team member is contributing to the assignment and also communicating well to see this through. Each member’s knowledge has been consolidated into this report. Below is the percentage of effort towards this assignment by each member.
Alex Stanton / Carolina Tejada / Steve Orcioulo / Joe BovaPercentage of effort towards this assignment / 25% / 25% / 25% / 25%
Section 2:
Programming (Caronlina and Joe):
For our uses an Arduino board may suit us best. It has its own program to program the microcontrollers. Arduino boards are relatively cheap so they can be widely implemented in street lights across great distances. The software can be run and programmed on Windows, Mac, and Linux. The software that comes with the board does not require expert knowledge, although having such knowledge would greatly benefit the customer. The language used by this board will be C++, a language we took as a requirement of engineering at Stevens. Having basic knowledge of this language will help us understand the more complex parts to writing the code. Also with Arduino their boards are open to change, they can be extended and improved by its users even if inexperienced.
Board Specifications (Steve):
While looking at the Arduino Boards for the motion sensor highway lights, we had to determine our needs in order to choose the right board. First, were the voltage requirements. Since we are going to run the Ardunio of the pre-existing power supply to the lights, we had to make sure we would have enough volts. Most highway lights have a light that requires 480 volts. Since most of the boards require less than 10 volts, this was not a problem for us. The next was the digital and analog input and outputs. Digital and analog input and outputs allow the signal from the motion sensor or any other senor to be transmitted and ran through the code embedded in the microprocessor board. Also, we need to look if we wanted to make this a wireless grid system where the devices can communicate with each other and determine where the lights need to be turned on or off. Another option we had was an Ethernet port. The Ethernet port would allow use to collect data from the microprocessor and be able to connect to a system. For this project, we decided to go with a simple Arduino, the Arduino uno.
Adruino Uno
The specifications are:
Microcontroller / ATmega328Operating Voltage / 5V
Input Voltage (recommended) / 7-12V
Input Voltage (limits) / 6-20V
Digital I/O Pins / 14 (of which 6 provide PWM output)
Analog Input Pins / 6
DC Current per I/O Pin / 40 mA
DC Current for 3.3V Pin / 50 mA
Flash Memory / 32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM / 2 KB (ATmega328)
EEPROM / 1 KB (ATmega328)
Clock Speed / 16MHz
It can be powered via USB or external power source. The external power source can either come from an AC to DC adapter or battery. Leads can come from the battery and connected into the Vin and Gnd pins on the board. The power pins are:
Vin-the input voltage to the Arduino board
5V-this is the pin outputs a regulated 5V from the regulator at the board.
3V3-this is a 3.3 Volt supply generated by the on-board regulator. It has a current draw of 50mA
GND-this is the ground pin
IOREF-this pin provides a voltage reference with which the microcontroller operates.
There are 14 digitals pins on the Uno that can be used as input or outputs. Each one operates at 5 Volts and can provide or receive a 40mA and has an internal pull-up resistor of 20 to 50KOhms.
Ports include:
Serial 0 and 1-this is used to receive and transmit TTL serial data
External Interrupts 2 and 3-these pins can be configured to tripper an interrupt
PWM-this provides an 8 bit PWN output with the analogWrite() function
SPI-these pics communicate with the SPI library built it
Along with the digital inputs and outputs there are 6 analog inputs, which we will most likely be using in this project. The inputs provide a 10 bit resolution. The pins also have a 5 Volt source and can be programmed through the analogRefernence() Function.
The Arduino Uni is also very small are 2.7x2.1 it cn easily fit into any space and be able to go into any enclosure. The price is approximately $30. If we want to, we can get the same microcontroller but for $20 additional we can use LabVIEW instead of the Arduino language.
Section 3:
Realistic Constraints (Alex):
Ideally, this product will yield. Realistically, however, some issues could emerge. The biggest potential issue is that the circuitry used to control the bulb will consume more power than the bulb itself. As this product is made to reduced energy consumption and thus save money, it would be worthless if it ended up using more energy. The product will not be constrained too heavily environmentally. The only constraint in this area will be designing it with parts that comply with certain environmental standards, such as RoHS, for when the product is eventually disposed. It will also require an environmentally sealed case to protect the interior circuitry. This won’t be a large issue as many new electrical components no longer incorporate environmentally unfriendly materials. Health and safety won’t present an issue to the final design as in order for it to be unsafe, it would fail to perform its core duties by not properly illuminating the streets. The product would be easily manufactured, as it’s basically a circuit board inside of a case. The product would be easily sustainable, as it would only require minimum maintenance that could likely be done in tandem with existing maintenance of streetlights.
Professional and Ethical Responsibilities (Alex):
The main ethical responsibility of this product is to ensure that streets are properly illuminated at all necessary times for the safety of the drivers. This means that the device will have to function properly, and in the situation that something unpredictable happens have a backup method of running the light fulltime if switching the light on and off fails.
Section 4:
Low Cost per Unit: Make each unit cost a low amount so the money saved on power will exceed the initial cost in a reasonable amount of time
Consume less energy than the bulb: Make each unit consume less energy than the light bulbs themselves so that money is saved on power
Saves significant amount of energy: Saves a notable amount of energy so the product is rightfully marketed as environmentally friendly, or “green”
No significant amount of harmful materials when disposed: Only use components that have no harmful materials to the environment when disposed, such as lead
Reference List:
http://arduino.cc/en/Main/arduinoBoardUno