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Peripherals and their Control An overview of industrially available “peripheral devices”. Some ideas for Laboratories and Quiz / Exam questions. To be tackled today. Analog Output Devices
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Peripherals and their ControlAn overview of industrially available “peripheral devices” Some ideas for Laboratories and Quiz / Exam questions
To be tackled today • Analog Output Devices • These could be handled via A/D as we did with an audio signal in Lab. 1. Depends on amplitude and frequency of the signals generated by the devices. • SPI devices – Tackled in Lab. 4 • LCD screen using a serial parallel converter • MC33993 Multiple -- Switch Detection Interface • ADIS16003 accelerometer and temperature sensor • Digital Output – modulated pulse width • Handle with PF interface as with switches • ADI - TMP03 thermometer – Lab. 3 • ADXL213 Dual Axis Accelerometer – Done in lecture • Those interested – might be able to work out special Lab. 3 substitute – Four times the fun – eight times the work?
MMA6260QDual Axis Accelerometer Left Channel ? Right Channel? • Could we modify the “Talk-through program from Lab. 1 to work withthis accelerometer? • Concern 1 – voltage levels – can’t blow Blackfin A/D • Concern 2 – is the 48 kHz bandwidth of the audio A/D enough • Probable solution – use a non-audio, more general A/D connected via SPI interface
MMA6260Q Dual Axis AccelerometerUsed as “tilt” sensor – static mode
MXPM2010 – Pressure sensor Differential pairoutput How connect to A/D? Convert tosingle sided signalvia op-ampand then connect?
33794 – Electric Field Sensor-- Uses ISO-9141 dual-wire protocol
ISO-9141 • Road vehicles – diagnostic systems • Requirements for exchange of digital information • Can be converted to RS-232 via a chip
Possible application PAD 1 Detect If Your Drink Has Been moved PAD 2
SPI interface chips -- Used during Lab. 4. • Ability to send data over 1 line • Master Out Slave In – MOSI • Ability to receive data over 1 line • Master In Slave Out – MISO • Control many devices using a chip-select (CS) line • Can use PF1, PF2 …………… PF7 • PF0 line can be used to switch Blackfin into a slave mode
Master / Slave conceptSlave Select (Chip Select) • Master sends out active low chip select signal SS1, then slave 1 responds • Master sends out active low chip select signal SS3, then slave 3 responds PF5 PF6
Lab. 4 SPI interface project SPI signals from Blackfin1 line (MOSI) + Clock + PF5 (SSI) 16 output linesused to control LCD screen
Multiple Switch Detection InterfaceMC33993 – Part of security system laboratory Blackfin MOSICLKPF5MISOPF9PF10?
MC33993 – Timing info Bits value = switch On/off – stream of 20 bits SG13 ON/OFF, SG12 ON/OFF, SG11 ON/OFF ----- SO0 ON/OFF ………….
ADIS16003 – Uses SPI interfaceDual axis accelerometer AND Thermometer CLKPF5 MISO PF6
ADIS16003 – Uses SPI interfaceDual axis accelerometer AND Thermometer
Serial Digital Output • Analog values – say temperatures from minus 40C to plus 100 measured • Value converted into “pulse length information” – digital signal • Transmitted over a single wire
ADI – TMP03Serial Digital Output Thermometer GROUND WIRE +5VPF8 connection on Blackfin Interface
More information on the sigma-delta modulator used to generate TMP03 output
ADXL213 Dual Axis Accelerometer PF9 PF8
ADXL213 Dual Axis Accelerometer PF9 PF8
ADXL213 Dual Axis AccelerometerOutput when used as “tilt sensor” X 50%Y 80% X 50%Y 20% X 50%Y 50%
Reference Information • Pictures are taken from various data sheets available from the Analog Devices and Freescale (Motorola) web sites • Proposed use of devices are for concept purposes only and no guarantee is made regarding suitable of circuits suggested • Application notes are also available on the website