NiR: Networked Intelligent Relay

Karl Bowers: Failsafe

Drew Holbrook: Thinkpad

The proposed project is a implementation of a intelligent, networked relay board for use in electrically noisy environments. This project is designed to fill the current need for a general purpose computer controllable relay board, which has the ability to provide the status of all power inputs and electrical loads. The wired network protocol to be used will be a Controller Area Network (CAN) setup. The decision to use to CAN was made due to its excellent signal integrity in high noise environments. CAN uses differential voltages to represent its logic states instead of relying on zero volts for its LOW state. Moving the LOW logic state away from a ground, reduces the chances of interference inducing a false HIGH logic state.

The primary goal for this stage of design, to be completed in the allotted time, is to produce a working network controlled relay board. The project will consist of a combination of commercial development boards and a custom designed bread-boarded relay and status monitoring circuit. After the course is completed, our intention is to continue development and move the CAN node containing the relay and status monitoring circuit to a printed circuit board. Our ultimate goal, to be completed at a later date, is to implement multiple nodes and show the networks ability to handle messages of varying levels of priority.

Determine Parts List Submit Parts Request Initiate Website layout

Create System Overview Diagram Create MultiSim simulation of preliminary design of relay, status monitoring circuit Establish communication from the MCU to CAN controller using SPI

Establish communication From one CAN node to another CAN node Prototype preliminary circuit design on Breadboard (If all parts are in)

Establish communication between Master CAN node and CAN node containing the relay circuit Inspect relay circuit for proper operation

Additional work to be determined based on meeting previous goals To include: Terminal application on main computer Possible GUI application based on Qt using QT Creator Example practical application to demonstrate advanced capabilities of smart Relay board

Full Parts List

• PIC32 Microcontroller - Product Website
• PIC-MCP2515 CAN Controller - datasheet
• PIC-MCP2551 CAN Transciever - datasheet
• Current Sensing Resistors -datasheet
• Low Dropout (LDO) Regulators 5.0V/1.5A -datasheet
• Low Dropout (LDO) Regulators 3.3V/0.8A - datasheet
• Low Dropout (LDO) Regulators 3.3V/1.5A - datasheet
• Transistor Output Optocouplers Phototransistor Out Quad - datasheet
• Industrial Relays (SPDT) w/ Supression Resistor - datasheet
• Current Sensing Resistors - datasheet
• Standard LED, High Efficeincy Red - datasheet
• Fuseholders - datasheet
• Relay Sockets - datasheet
• Transistor Output Photocouplers - datasheet
• Current Sensing Amplifier IC - datasheet
• 20MHz Crystal - datasheet
• Solid State Relay - datasheet

• Documentation Photos

• Technical Drawings

• Software Documentation

Full system electronic testing will not be possible with the MultiSim simulation program due to its limited library. Some integrated chips that we have initally chosen cannot be located within this program.

Parts list has been generated. More circuit calculations need to be completed to properly identify some remaining parts. Final parts list and submittal expected early next week. The Wiki has not been started due to website registration issues and will have to be initiated at the beginning of next week. To keep forward progress; initial system and circuit (node) design will be started using VISIO.

Project Wiki has been started. Sample node circuit has been generated and needs to be customized on specific loads we intend on using for the final presentation. Relays have still not been selected.

All parts have been ordered and we are waiting for shipment. The Preliminary circuit diagram was started using Visio. Both Karl and Andrew were sick this entire week, so process has been slow.

Today, the bulk of our parts arrived. The technical drawings are still in progress and should be posted sometime tonight. Coding is still in progress and some of the initial code was posted earlier by Karl. Initial circuit construction will be in progress tonight or tomorrow morning.

Karl and I made an attempt at meeting up but couldn’t due to scheduling conflicts. This past Friday,Karl attached some of our larger components to an unpopulated circuit card for the load circuit. Updates to the parts list have been made for miscellaneous resistors and capacitors we are using. Also,I have completed some of the calculations that indicate which resistors will be used to limit the current feeding the monitoring circuit of the microcontroller. Pictures will hopefully be updated tomorrow to show the circuit progress.

A lot of progress was made last week but, it has become apparent that we will not meet our proposed deadline of a fully operational Intelligent Relay System. Due to substantially more time being spent on the hardware portion of this project, coding will not be fully completed. On Friday/Saturday, coding for simple circuit relay switching was successfully completed. The next steps will be to code the current monitoring levels and control the fail indicator (LED) for when the fault occurs.