Basic requirments to work in Embedded development world.

C language(0)

데이터 시트 읽는 능력(1)

• gpio(general-purpose input/output)
• pwm(pulse width modulation)
  • make it like analog signals by differentiating ratio(duration time) of digital signals(high and low).
  • Human eye cannot recognize whether LED lamp blinks or not if the frequency is over 100 Hz.
  • Duty Cycle : time ratio of high and low signals, (duration time of high signal)/(duration time of low signal)
  • It enables such like analog-output signal control by digital-output signals.
  • Motor control could be one example, if duty ratio is going to high, velocity will be faster.

concept of duty cycle

About and differences of i2c, spi, uart communications

1. i2c(inter integrated circuit) :

• Half duplex mode, synchronous, low speed.
• 100 kbps(standard)
• It consists of 2 eletrical lines,
  • SCL(Serial Clock) : carries clock signal
  • SDA(Serial Data) : allosw master and slave to send and recieve data.

i2c layout

2. spi(serial peripheral interface) :

• Full duplex mode, synchronous, high speed.
• 250 Mbps @ .1m
• It has 4 lines.
  • MOSI(Master Out, Slave In)
  • MISO(Master In Slave Out)
  • SCKL(Serial Clock)
  • SS(Slave Select)

spi bus

3. uart : Universal Asynchronous Reception and Transmission

• full duplex mode, asynchronous
• 20 kbps @ 15m
• uses 2 wires(Tx, Rx)

uart communication

reference : https://www.nextpcb.com/blog/spi-i2c-uart

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회로도 해석 능력(2)

ARM 코어 구조(3)

하드웨어 디버깅 능력(2) (GPIO 제어 능력)

• 오실로스코프 사용 방법(1)
• 테스터기 사용방법(1)

Basic knowledge about electricity.

• DC(Direct Current)/AC(Alternating Current)
• Inverter, Converter
• What is Ground in eletricity?

운영체제가 있는 임베디드

free RTOS(취향에 따라 4순위 정도)

리눅스

• 컴파일 방법, gcc 사용법(1)
• 크로스 컴파일 개념(1)
• makefile 작성방법(1)
• 라이브러리 작성방법(2)
• 드라이버 구현 방법(1)
• 커널 컴파일 방법(1)
• 커널 포팅 방법(1)
• vi edit 쓰는 방법(3)
• gdb 쓰는 방법(4)
• path 설정방법(2)
• tcp, socket 통신 구현(1)
• 시리얼 통신 구현(1)

Reference

From OJ Tube