Transcript Possible Microprocessor Peripherals

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
– 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
TSL230R – Light sensor – Lab. 2
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?
MMA6260Q
Dual Axis Accelerometer – Analog Output
Left Channel ?
Right Channel?
Could we modify the “Talk-through program from Lab. 1 to work with
this accelerometer?
• Concern 1 – voltage levels – too high voltages would destroy 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
• How does
it work?
MMA6260Q Dual Axis Accelerometer
Used as “tilt” sensor – static mode
MXPM2010 – Pressure sensor
Differential pair
output
How connect to
Blackfin A/D which can’t
handle
differential voltages?
Convert
to
single sided signal
via op-amp
and 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
(Master sends, slave receives)
• Ability to receive data over 1 line
– Master In Slave Out – MISO
(Slave sends, master receives
• Control many devices. Each devices is “told to
listen” using a chip-select (CS) line
– Can use PF1, PF2 …………… PF7
– PF0 line can be used to switch Blackfin into a slave
mode (Two Blackfins talking to each other)
Master / Slave concept
Slave Select (Chip Select)
• Blackfin master
sends out active
low chip select
signal SS1, then
slave 1 selected
(responds)
• Master sends out
active low chip
select signal SS3,
then slave 3
responds
PF5
PF6
Lab. 4 SPI interface project
SPI signals from Blackfin
1 line (MOSI) + Clock + PF5 (SSI)
16 output lines
used to control LCD screen
or the radio controlled car
Multiple Switch Detection Interface
MC33993 – Part of security system laboratory
Blackfin
MOSI
CLK
PF5
MISO
PF9
PF10?
MC33993
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 interface
Dual axis accelerometer AND Thermometer
CLK
PF5
MISO
PF6
ADIS16003 – Uses SPI interface
Dual axis accelerometer AND Thermometer
ADIS16100 – Gryosensor
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 – TMP03
Serial Digital Output Thermometer
Will use the same
ideas in Lab. 3
GROUND WIRE
+5V
PF11 connection on Blackfin Interface
Block diagram for the TMP03
TMP03 Output characteristics
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 Accelerometer
ADXL213 Dual Axis Accelerometer
Output when used as “tilt sensor”
X 50%
Y 20%
X 50%
Y 80%
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