Two Way Remote Control

Two Way Remote Control

Dr. Abdelhafid Bouhraoua

Outline• Context, Motivations and Applications• Principle of Operation• Components• Implementation• Problems and Issues• Existing similar solutions• Perspectives

Context Motivations

Context MotivationsIn the House

Context Motivations

• Many Devices in the House can be controlled Remotely

In the House

Context Motivations


• Each Device has own Control Protocol

In the House

Context Motivations


• Each Device has own Control Protocol• All Devices can be Electrically

Controlled

In the House

Context Motivations


• Each Device has own Control Protocol• All Devices can be Electrically

Controlled

In the House

RF Remote Control

Applications

Applications• TV and A/V Systems


– Check Programs, Kids Watching, Control VCR (DVR or DVD), etc…



• Computer



• Computer– Email Not., Messenger, Audio, Video, etc…




• Appliances




• Appliances– Temperature Mon., Status of Appliances, etc…





• Safety





• Safety– Alarm, Smoke, Water or Gas Leakage, etc…

Principle of Operation


Master: Remote Control


Master: Remote Control

Slaves: Command Devices

Features (Remote Control)


• Color Graphic LCD screen

• Color Graphic LCD screen• Expandable keypad



• Color Graphic LCD screen• Expandable keypad• Two-way high bit rate communication


• Color Graphic LCD screen• Expandable keypad• Two-way high bit rate communication• Relatively large memory to store the

software


• Color Graphic LCD screen• Expandable keypad• Two-way high bit rate communication• Relatively large memory to store the

software• Variety of extra interfaces like USB

and Infrared (for TV/VCR/DVD control)

Features (Slave Devices)


• Two way communication


• Two way communication• Microcontroller (for intelligence)


• Two way communication• Microcontroller (for intelligence)• Many standard and custom

interfaces (to control to the devices)


• Two way communication• Microcontroller (for intelligence)• Many standard and custom

interfaces (to control to the devices)• USB (for the Computer Slave Device)

Components- LCD Display -

• Graphic LCD• Serial Interface• Available Connector

Nokia 6610 Color LCD

Components- RF Transceiver -

• Frequency Range: 2.4~2.524 GHz ISM band • Modulate Mode: GFSK • Data Rate: 1Mbps or 250Kbps • Multi channel operation: 125 channels, Channel

switching time<200uS, Support frequency hopping

• Emulated full duplex RF link due to the 1Mbits/s on the air data rate

• Including decoder, encoder and data buffer and CRC computation

• Burst mode for ultra-low power operation and relaxed MCU performance

• Sensitivity: -90dBm • Built in antenna • Power supply range: 1.9 to 3.6 V • Size: 20.5*36.5*2.4mm

TRF-2.4G Transceiver

Component- MP3 Player -

• MPEG audio layer 3 decoder (ISO11172-3), MPEG 1 & 2, and 2.5 extensions, all their sample rates and bit rates, in mono and stereo

• Can be used as a slave co-processor• Operates with single clock 12..13

MHz or 24..26 MHz• Low-power operation• On-chip high-quality stereo DAC

with no phase error between channels

• Internal Op-Amp in BGA-49 and LQFP-48 packages

• Stereo earphone driver capable of driving a 30 Ω load.

• Separate 2.5 .. 3.6V operating voltages for analog and digital

• Serial control and data interfaces

Component- MP3 Player Board -

• Board Based on VS1001 chip

• Simple board with all external passive components and voltage regulator for providing voltage to analog and digital parts of the chip.

• Conform to VS1001 Datasheet

• Designed and Manufactured by JELU (Sweden)

Component- Microcontroller -

• 512K SRAM• 512K Flash• Ethernet for Networked

Applications including web-enabled embedded apps.

• Many standard interfaces:– USART, SPI, I2C, SCI, Parallel Ports

• Many Timers for clock generation and PWM

• Provided Development Environment

• Standard ANSI-C language programming environment

• Many libraries spanning as wide as:– PWM, SPI, USART, GPS, Timer

Control, TCP/IP, etc …

Rabbit Semiconductor RCM3700 Microprocessor Core

ImplementationNo Board was Developed because of

Time constraints

• RCM3700 Successfully Interfaced with VS1001 MP3 Board– MP3 File playback successful

• RCM3700 Successfully interfaced with TRF-2.4G Transceiver– Simple Messages exchanged successfully

Problems and Issues Student involvement. Project proposed only because of a strong

student interest and commitment. However, interest did not materialize over time.

Malfunction in the MP3 player board ordered from the Jelu website. The board is built around a single chip: the VS1001. It took a large

amount of debugging and troubleshooting time from us to arrive to this conclusion. Valuable help of Mr. Victorioso M. Go (Dong Jr.)

who removed the 74LV245 from the board and solder directly bypass wires on the VS1001.

Socket for the TRF2.4G connector. This connector is a two-row, 10 post, 1.27 mm header. Again, Mr. Victorioso M. Go was the one who solved this logistical issue by making custom boards that

converts the connectors to standard 2.54 mm headers.• Interference in the 2.4Ghz band. TRF2.4Gs could not communicate

properly. WLAN coverage in building 22 was the problem. An experiment where I turn off the transmitter and work only with the receiver shows that:– Garbage Data is received as a result of the WLAN interferences even

when an 8-bits CRC is enabled.– The frequency of received garbage decreases dramatically but not

totally when 16-bits CRC is turned on.

Existing Solutions• Many RF Remote Control to control:

– TV and some Home Appliances and the PC– No Product customizable Yet– No Product with video streaming to the remote– No Two-way communication

• New standard for low bitrate communications: Zigbee Consortium.– Bit rate either 40 Kbps or 250 Kbps enough for

the application we were targeting– Many companies involved

• WLAN Remote Control– No Product found.

Perspectives• Use a Wireless LAN (WLAN) to carry

the remote control signals– Many embedded WLAN NICs available

(WiPort from Lantronix: www.lantronix.com)

– Offers many perspectives– No interference problems as it is the

same physical layer.

http://www.lantronix.com/

Documents

Two Way Remote Control