Homework 3: Design Constraint Analysis and Component Selection Rationale

Transcription

1 ECE 477 Digital Systems Senior Design Project Rev 811 Homework 3: Design Constraint Analysis and Component Selection Rationale Team Code Name: Home Kinection Group No. 1 Team Member Completing This Homework: Will McGrath Address of Team Member: purdue.edu NOTE: This is the first in a series of four professional component homework assignments, each of which is to be completed by one team member. The body of the report should be 3-5 pages, not including this cover page, references, attachments or appendices. Evaluation: SCORE DESCRIPTION Excellent among the best papers submitted for this assignment. Very few 10 corrections needed for version submitted in Final Report. Very good all requirements aptly met. Minor additionscorrections needed for 9 version submitted in Final Report. Good all requirements considered and addressed. Several noteworthy 8 additionscorrections needed for version submitted in Final Report. Average all requirements basically met, but some revisions in content should 7 be made for the version submitted in the Final Report. Marginal all requirements met at a nominal level. Significant revisions in 6 content should be made for the version submitted in the Final Report. Below the passing threshold major revisions required to meet report * requirements at a nominal level. Revise and resubmit. * Resubmissions are due within one week of the date of return, and will be awarded a score of 6 provided all report requirements have been met at a nominal level. Comments: Comments from the grader will be inserted here.

2 ECE 477 Digital Systems Senior Design Project Rev Introduction This system is designed as a novel interface to a more standard home automation system. It consists of a Microsoft Kinect sensor and computer that interface wirelessly with control modules. To succeed as a novel approach, the system needs to ensure that the interface is fluid, while maintaining the benefits of normal home automation systems. The system should also be compatible with as many home typical targets of home automation technology as possible. Additionally, the cost of the automation modules should fall close to the price of current comparable home automation modules. PSSCs: 1. An ability to control AC lightsappliances. 2. An ability to control IR-based devices (TV, etc.). 3. An ability to control a motorized shade (updown). 4. An ability to control a computer (via a "virtual touchscreen") using gestures and voice commands. 5. An ability to distinctly interpret the gestures and voice commands required for all control functions of the system. 2.0 Design Constraint Analysis As typical for a home automation system, cost and compatibility are major constraints for this project. Home automation systems typically include a single, costly central control unit and as many accessory modules as are necessary to achieve the desired degree of control over the home. It is important to keep the price of the accessory modules low, to ensure that constructing a large system does not become cost-prohibitive. In order to be useful for as many people as possible, a good automation system must also be able to interface with a wide range of typical home appliances. People expect a user interface to be responsive, so for both the HID module and the general control interface, low latency is key. Although all of the modules will be connected to continuous sources of power, for the sake of simplicity, none of the modules should draw enough electricity to require active cooling. Additionally, the HID module will be powered by a USB port and should not exceed the 500mA maximum available from it according to [1]. The size of the module boxes should be small enough for discrete integration into a home environment and -1-

3 ECE 477 Digital Systems Senior Design Project Rev 811 the base station should not be larger than a standard media center computer. The range of the wireless communications involved needs only to span a standard large room, roughly 30 feet maximum. 2.1 Computation Requirements The project s user interface depends on a Microsoft Kinect sensor and the associated SDK provided by Microsoft. The SDK runs on Windows 7 and employs algorithms that convert a field of range measurements to information about the estimated position of a user s body. The SDK also provides for voice recognition using the Kinect sensor s array of four microphones. The team is also developing custom gesture recognition software that will convert the user s actions to commands to be issued to the module boxes. In order to run both the SDK s algorithms and our gesture recognition algorithm, a fairly powerful computer is required. The computer needs to have at least a dual core 2.66GHz processor and 2GB of RAM as well as direct 9c support according to [2]. Although the module boxes will not perform any difficult calculations, latency is a concern, particularly for the HID box. The user will gesture, it will be captured by the Kinect, interpreted and a wireless command will be send to the appropriate module box. The module box needs to receive that command and perform the intended action as quickly as possible to minimize lag. Ideally, the latency due to the rest of the system will small compared to the latency of the Kinect sensor. 2.2 Interface Requirements The function of relaying data wirelessly from the base module to the different varieties of module boxes and allowing them to perform their functions necessitates a diverse range of interfaces. A table of interfaces and protocols can be found in Appendix C. All of the module boxes and the daughterboard communicate with the wireless modules using SPI. The SSR in the A.C. dimmer circuitry, the IR LED in the IR control box and the indicator lights on all of the boxes require standard PWM outputs. The dimmer module will also include a physical slider as an alternative control, which necessitates an AD channel for that module. Communications between the daughterboard and the motherboard and communications between the HID module s microcontroller and its USB interface chip will be handled with SCI. Input of IR commands and -2-

4 ECE 477 Digital Systems Senior Design Project Rev 811 control of the simple interface for the shade module will be performed using standard GPIO. Detection of the 0V point of the AC signal for the dimmer will also be handled by an GPIO reading the output of an optoisolator connected to the AC line. 2.3 On-Chip Peripheral Requirements The base station needs to interface both with the Kinect sensor and its daughterboard. The Kinect interface will be handled by USB and the daughterboard interface will use SCI, both are features commonly available on modern motherboards. The daughterboard s microcontroller will require an SCI for communicating with the motherboard and an SPI to communicate with the wireless module. The module boxes will each require 1 SPI interface to communicate with their respective wireless modules and 3 PWM channels to drive their status LED. The shade module is the simplest, it only requires an additional 2 GPIO pins to drive relays for the Lutron CCI interface. The IR module will use one PWM pin to drive its IR LED and a GPIO to receive IR. The dimmer will use a PWM to drive the SSR, an AD to read a manual input and a GPIO to read the A.C. zero point detector. The HID box requires only an extra SCI channel to communicate with the USB interface chip. 2.4 Off-Chip Peripheral Requirements The base station and daughter board only require the Kinect and wireless module off-chip. The module boxes all require a wireless module and different peripherals depending on their interface needs. The dimmer requires an SSR and zero point detector to dim an A.C. load. The IR interface requires an IR LED and 40kHz IR receiver module. These should allow the IR box to interface with most consumer AV equipment. The shade module requires two relays to interface with the 24V DC CCI interface. The HID module requires a USB interface chip to communicate HID commands to the computer it controls. HID commands are standard and should work with any modern computer. 2.5 Power Constraints All of the modules are designed to be continuously attached to a power source. The motherboard, daughterboard and all modules except the HID module will have AC-DC power supplies built-in. -3-

5 ECE 477 Digital Systems Senior Design Project Rev 811 Although the dimmer circuit will be handling A.C. loads, ideally it will not dissipate enough heat to require active cooling. The HID module box will be powered by the DC 5V provided by USB and must not exceed the 500mA limit of a single port. 2.6 Packaging Constraints The project s packaging needs to be unobtrusive, but the primary concern is that it must not obstruct the radio communications of the wireless modules. To this end, they must be large enough to allow adequate separation between the power supply section and the antenna as well as not made of metal if the antenna is mounted internally. The base station only needs to be large enough to contain a small motherboard as well as the daughterboard and wireless module. The same considerations regarding power supply and antenna separation apply to this package as well. 2.7 Cost Constraints Our project aims to compete with the cost of current home automation hardware. The module boxes should be priced similarly to current boxes implementing upgraded protocols similar to X- 10. These control boxes cost roughly $30-$50 according to [3]. The base station is permitted to be rather expensive due to the high cost of existing home control systems. Lutron has several offerings well over $1000 according to [4]. 3.0 Component Selection Rationale After the broad functionality of each of the module boxes was decided, we were able to pick components to implement each module box s interface. Based on the interface required by each module box, we were able to decide on a microcontroller that had the correct on-chip peripherals to interface with the off-chip peripherals. In the case of this project, the most important selections were those of the microcontroller, wireless module and motherboard. The PIC18F27J53-ISO in [5] had sufficient SCI, SPI and PWM pins, supported USB and was inexpensive. If this microcontroller was chosen we picked the MRF24J40MA wireless module to go with it. The MRF24J40MA, found in [6] is only $9, uses SPI and supports the Zigbee protocol. However, we found a module that incorporates both a Zigbee-compliant AT86RF230 radio and an ATmega1281V microcontroller called a ZigBit in [7]. The ZigBit was -4-

6 ECE 477 Digital Systems Senior Design Project Rev 811 selected because has all of the required on-chip peripherals and simplifies the integration between the wireless module and microcontroller. We required a motherboard that was small, could support a modern Intel or AMD desktop processor, had USB ports and if possible, a serial port. We first considered the Intel BOXDB43LD LGA 775 in [8], which had a Micro ATX form factor and a padded-out serial port. However, we settled on the Intel BOXDQ45EK LGA 775 in [9], which had a slightly smaller Mini ITX form factor and its serial port is not padded-out. This allows us to interface directly to the board and avoid a spurious serial cable in our package. 4.0 Summary Based on careful consideration of the effect each part selection has on the above listed parameters, the parts listed in Appendix B represent a viable solution that fits within them. The average cost per module should be near $50, as anticipated. The selected wireless module and microcontroller combination board meet our planned requirements for the functionality of the module boxes. -5-

7 ECE 477 Digital Systems Senior Design Project Rev 811 List of References [1] Pinouts.ru Database, USB connector pinout, [2] Microsoft Research, Kinect SDK minimum requirements, [3] Smarthome Online Catalog, Insteon Lamp dimmer, Module-3-Pinp.aspx [4] Pro Lighting, Lutron Control Packages, [5] Microchip, PIC18F27J53 Product Page, [6] Microchip, MRF24J40MA Product Page, [7] Atmel, ZigBit documentation, [8] Newegg, Intel BOXDB43LD Product Page, DB43ld [9] Newegg, Intel BOXDQ45EK Product Page,

8 ECE 477 Digital Systems Senior Design Project Rev

9 ECE 477 Digital Systems Senior Design Project Fall2008 Appendix A: Parts List Spreadsheet Vendor Manufacturer Part No. Description Unit Cost Qty Total Cost Mouser Atmel ATZB-24-A2R ZigBit Module (Radio transceiver, $150.4 antenna, Microcontroller) Mouser Crydom CX240D5R Solid State Relay $13.41 Mouser Vishay TSOP75236WTR IR receiver $1.35 Mouser Maxim MAX3420EECJ USB Interface $8.94 Mouser Omron 653-G6K-2F-Y-DC3 Mechanical Relay $5.36 Mouser Fairchild H11A1 Optocoupler $0.49 Microsoft Microsoft Kinect Kinect sensor $ Newegg Intel BOXDQ45EK Mini-ITX Motherboard $74.99 Mouser ALPS RS301111AA06 Slide Potientiometer $0.76 Mouser ROHM SMLW56RGB1W1 RGB SMD LED $13.75 Semiconductor Mouser C&K Components PTS525SM10SMTR Pushbutton $4.80 LFS Newegg Intel BX80571E GHz Dual Core Processor $59.99 Newegg Western Digital WD5000AAKX 500 GB HDD $44.99 Newegg Kingston KVR800D2K2 4GB RAM kit $42.99 TOTAL $

10 ECE 477 Digital Systems Senior Design Project Fall

11 ECE 477 Digital Systems Senior Design Project Fall2008 Appendix B: Updated Block Diagram -10-

12 ECE 477 Digital Systems Senior Design Project Fall2008 Dimmer Module Power Supply AC Power H11A1 (Zero Cross) 1--- (GPIO) 1 (PWM) Crydom CX240D5R (AC SSR) 1 AC Load ZigBit ATZB-24-A2 ATmega1281V (MCU) 3 (PWM) 1 AD RGB Led 4 (SPI) Slider Dual Antenna 5 AT86RF230 (Radio Transciever) 1 - GPIO Push Button Shade Module Power Supply AC Power 2 GPIO G6KU-2F-YDC3 (Relay) Lutron Stanza Shade ZigBit ATZB-24-A2 ATmega1281V (MCU) 3 (PWM) 1 GPIO RGB Led 4 (SPI) Push Button Dual Antenna 5 AT86RF230 (Radio Transciever) 1 - GPIO Push Button -11-

13 ECE 477 Digital Systems Senior Design Project Fall2008 IR Module AC Power Power Supply IR Reciever 1 UART 3 PWM IR LEDs ZigBit ATZB-24-A2 ATmega1281V (MCU) 3 (PWM) 1 GPIO RGB Led 4 (SPI) Push Button Dual Antenna 5 AT86RF230 (Radio Transciever) 1 - GPIO Push Button -12-

14 ECE 477 Digital Systems Senior Design Project Fall2008 HID Module Power Supply DC Power (USB) 4 SPI MAX3420E USB Controller USB Computer ZigBit ATZB-24-A2 ATmega1281V (MCU) 3 (PWM) RGB Led Dual Antenna 5 4 (SPI) AT86RF230 (Radio Transciever) AC Power Mother Board Application Gesture Library (Files) Daughter Board Power Supply Gesture Recognition Engine Kinect USB Kinect SDK Voice Recognition Engine Serial (UART) ZigBit ATZB-24-A2 ATmega1281V (MCU) 3 (PWM) RGB Led Room Calibration 4 (SPI) Dual Antenna 5 AT86RF230 (Radio Transciever) -13-

15 ECE 477 Digital Systems Senior Design Project Fall2008 Appendix C: Interface Pins Table Interface Protocol Channels Required Module box to wireless module SPI 1 Base station to Kinect USB 1 Base station to daughterboard SCI 1 Zero Point detection GPIO 1 SSR activation PWM 1 IR Output PWM 1 IR Input GPIO 1 CCI to blinds GPIO 2 Dimmer input AD 1 HID to USB interface SPI 1 Driving indicator light PWM 3-14-