Electronics for the Internet of Things

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Electronics for the Internet of Things

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Electronics for the Internet of Things

  1. 1. Electronics for the Internet of Things SUMMER SCHOOL
  2. 2. Outline Electronic Signals Electricity Equations General Purpose Input / Output (GPIO) Pulse Width Modulation (PWM) Analog to Digital Converters (ADC) Microcontrollers and Computers Questions 2
  3. 3. Electronic Signals 3 Image from http://autosystempro.com/analog-and-digital-principles/
  4. 4. Analog and Digital We can only store digital signals ◦ Using 1 or several bits / sample We store an array of numbers Parameters ◦ Bits per sample ◦ Sampling rate 4 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  5. 5. Bits per sample 1 bit signals sample ◦ Values LOW (0) and HIGH (1) ◦ digital n bits signals sample ◦ Values 0 .. 2n-1 ◦ digital representation of an analog signal (analog) 5 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  6. 6. Sampling Sensor signals are analog 6 Image from http://www.snotmonkey.com/work/school/405/overview.html
  7. 7. Sampling Rate The faster we sample the higher the accuracy Nyquist Theorem ◦ Sampling frequency >= 2 x maximum frequency Voice is 0.3 .. 3.4 KHz ◦ 8KHz phone 7 Image from http://www.jazzpoparkisto.net/audio/audio32.html
  8. 8. Electricity Equations 8 I = U R kik å = 0 kEk å = kR kIk å
  9. 9. Ohm’s Law 9 I = U R I = 3V 10W+50W+ 60W = 0.025A = 25mA
  10. 10. Kirchhoff Law I 10 kik å = 0 - 1I + 2I + 3I = 0
  11. 11. Kirchhoff’s Law II 11 kEk å = kR kIk å 1L : E = 1I 1R + 3I 3R 2L :0 = 2I 2R - 3I 3R
  12. 12. Voltage Divider 12 1V + 2V = inV 1V = I 1R 2V = outV = I 2R We measure Vout
  13. 13. Voltage Divider 13 1R = 0 outV = ?
  14. 14. Voltage Divider 14 1R =¥ outV = ?
  15. 15. Voltage Divider 15 2R = 0 outV = ?
  16. 16. Voltage Divider 16 2R =¥ outV = ?
  17. 17. Voltage Divider 17 1R = 0 2R = 0 outV = ?
  18. 18. Voltage Divider 18 1R = 0 2R = 0 outV = ? Short circuit
  19. 19. General Purpose Input / Output 19
  20. 20. Output and Input Digital Pins ◦ Value LOW (0) or HIGH (1) Each pin acts like a ◦ battery (OUTPUT) ◦ voltage meter (INPUT) 20
  21. 21. Output Pins act like a battery ◦ LOW – 0V ◦ HIGH – 5V, 3.3V or 1.8V 21
  22. 22. Input We measure Vout ◦ It goes into the pin 22
  23. 23. Pulse With Modulation 23
  24. 24. Pulse Width We set the % of “high” cycle ◦ 0 – 0% ◦ 255 – 100% ◦ Depends on the library Implementation ◦ Hardware ◦ Software Usage ◦ LED dimming ◦ Servo Motors 24
  25. 25. Analog to Digital Converters 25
  26. 26. Analog and Digital Converters Measure voltage Parameters ◦ Bits per sample ◦ Sampling rate For 1 bit we have … 26 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  27. 27. Analog and Digital Converters Measure voltage Parameters ◦ Bits per sample ◦ Sampling rate For 1 bit we have … ◦ GPIO Input 27 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  28. 28. Analog and Digital Converters Measure voltage Parameters ◦ Bits per sample ◦ Sampling rate For 1 bit we have … ◦ GPIO Input 28 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  29. 29. Analog and Digital Converters Measure voltage Parameters ◦ Bits per sample ◦ Sampling rate For 1 bit we have … ◦ GPIO Input For n bits we have … 29 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  30. 30. Analog and Digital Converters Measure voltage Parameters ◦ Bits per sample ◦ Sampling rate For 1 bit we have … ◦ GPIO Input For n bits we have … ◦ 0 – 2n-1 30 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  31. 31. Analog and Digital Converters One ADC Multiplexed ◦ Reads for A0 ◦ Reads for A1 ◦ Reads for A2 ◦ Reads for A3 … 31 Image from http://www.centerpointaudio.com/Analog-VS-Digital.aspx
  32. 32. Microcontrollers and Computers 32
  33. 33. Microcontrollers and Computers Simple systems Control hardware Low speeds Small memory GPIO PWM ADC Run single software Full CPUs High speeds Large memory GPIO Run OS
  34. 34. Microcontrollers and computers Firmware Software
  35. 35. Intel® Edison Firmware (will be available) Software
  36. 36. Questions? 36

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