Ch3 HardWare

1. Eembbedded System(嵌入式系统)

  1. Bulit into the device

  2. Combination to hard ware & sotf ware for specific functions

  3. Must contain Processor,Memory & input/output

  4. Hard to upgrade

2. \(\clubsuit\) Hardwares

2.1 Laser Printer

  1. Revolving drum(OPC drum) is initially given charge (-)

  2. Laser beam reflects by mirrors

  3. Scans back & front across the drum

  4. Discharging certain parts of the drum

  5. The drum is coated with oppositely charged toner

  6. The drum rolls over electro-statically charged paper

  7. The pattern on the drum is transferred to the paper

  8. The paper is passed through the fuser to seal the image

  9. The electrical charge is removed from the drum

2.2 3D - Printer

  1. object design in the CAD software

  2. Software converts the design into slices

  3. Data of all slices are sent to the printer

  4. Repeat untill all slices are printed

    1. Solid plastic melted and transfered to the nozzle

    2. Repeat untill layer finished

      • Stepper motor moves the nozzle to the correct position
      • Nozzle deposits the melted plastic

    3. Cooling the plastic with a fan

2.3 Microphone

  1. Have a diaphragm

  2. Sound waves vibrate the diaphragm

  3. Use coil and magnetic for electric signal

  4. Sound signal is transmitted to the Electrical signal

2.4 Speaker

  1. contain Diaphragm, coil & magnetic

  2. Connect electric signal in changing the current

  3. Diaphragm connect to the coil

  4. Diaphragm vibrate to produce sound

  5. Sound enhance the dust cup

  6. Electrical signal is transmitted to the Sound signal

2.5 Magnetic Hard Disk

  1. Have one or more disks inside

  2. Surface of the disk can be magnetized

  3. Stored in a box (Aluminm)

  4. Disk rotate at high speed

  5. Surface of disk have an arm for read

  6. Surface of disk divided to sectors

  7. One track of sector is called a block

  8. Data stored as magnetic patten for each block

  9. Change the current when writing

  10. Produce magnetic field on disk

  11. Variation of magnetic field produce different current when read(纯物理知识)

2.6 Solid flash memory

  1. No moving parts(compare to magnetic hard disk)

  2. Solid state memory is non-volatile

  3. Contain blocks of NANd,NOR,transistor integrated ciruits

  4. SSD(Solid State Drive) controller manages the components

  5. Grid of colums and rows contains two transistors

  6. First transistor is floating gate

  7. Second transistor is control gate

  8. Memory store voltage repensent 1&0

  9. Read & write is control the movement of \(e^-\)

  10. Need to erase the old data before rewrite

2.7 Optical Disk(CD/DVD)

  1. Drive motor is used to spin the disk

  2. Tracking mechanism moves the laser beam

  3. Len focus the laser beam to the disk

  4. Read&write is the variation of strength of laser

  5. laser change the metak layer on surface of disk

  6. Reflected light then encode as bit pattern

Screems

Capactive touch screen

  1. Made by capactor that store charge

  2. When touched charge transferred to the finger

  3. Touched point discharge

  4. Electrostatic field of the point changes

  5. Coordinates of the point caculated

Ressive touch screen

  1. Two layer with charge

  2. Upper layer made of plastic

  3. Lower layer made of glass

  4. Circuit complet when two layer touches

  5. Coordinates of the touched point caculated

3. Use of Buffer

  1. Act as a temporary storage

    • Printer use buffer to store data from computer

  2. Used as Reserve devices

    • Video buffer when streaming

  3. Allow devices work in different speed *Key board buffer when data entry

4. RAM & ROM

4.1 Random Access Memory

  1. Temporary memory device

  2. Volatile memory

  3. Can be wiritten to and read from

  4. Store data,file,program & some parts of OS currently in use

  5. Can increase size to reduce operation time

4.2 Read Only Memory

  1. Permanent memory device

  2. Non-volatile memory

  3. Data hard to change

  4. Store BIOS and other data at start

5. SRAM & DRAM

  • SRAM is much faster than DRAM

  • DRAM is cheaper and more common than SRAM

5.1 DRAM(Dynamic RAM)

  1. Contain numbers of Transistors & Capacitors

  2. Need constantly refresh

  3. Higher memory capacity than SRAM

  4. CHEAP, Move power

5.2 SRAM(Static RAM)

  1. Use filp-flops to hold each bit of data

  2. Do not need refresh

  3. Faster access than DRAM

  4. Used in processer memory cache处理器缓存

  5. Expensive , Less power

6. PROM,EPROM,EEPROM

Functions PORM ERPOM EEPROM
Set: Only once Many times Many times
Erase: Can't Need device Directly erase
UV light Voltage
Before write: Can't Clear all data Directly write

7. Moniting and control system

(画流程图)

逻辑门

(幽默IG物理)

NOT

Input Output
0 1
1 0

AND

Input 1 Input 2 Output
0 0 0
0 1 0
1 0 0
1 1 1

OR

Input 1 Input 2 Output
0 0 1
0 1 1
1 0 1
1 1 0

NAND

Input 1 Input 2 Output
0 0 1
0 1 1
1 0 1
1 1 0

NOR

Input 1 Input 2 Output
0 0 1
0 1 0
1 0 0
1 1 0

XOR

Input 1 Input 2 Output
0 0 0
0 1 1
1 0 1
1 1 0