Peripherals

BNO055

• Adafruit BNO055 Absolute Orientation Sensor

HT16K33 LED Backpack

• 0.54" 14-segment LED HT16K33 Backpack
• Default I2C address of the display is 0x70
• documentation
• Adafruit_CircuitPython_HT16K33 How-To

import board
import busio as io
i2c = io.I2C( board.SCL, board.SDA )
import adafruit_ht16k33.segments
display = adafruit_ht16k33.segments.Seg14x4( i2c )#, address=0x74)
display.fill(0)
display.print('CPY!')
display.show()

Velleman VMA412 RGB TFT display

• VMA42 website with downloads
• 2.8" touch screen, 240x320 RGB, ILI9341 display driver
• CircuitPython display driver for ILI9341
• CircuitPython touch screen library
• Most examples use four-wire SPI bus, plus calls into displayio objects/methods

74HC595

• Texas Instruments SN74HC595N 8-Bit Shift Registers With 3-State Output Registers
• Cost $4.84/4
• 8-bit serial-in
• parallel-out shift register that feeds an 8-bit D-type storage register
• The storage register has parallel 3-state outputs
• Separate clocks are provided for both the shift and storage register
• The shift register has a direct overriding clear (SRCLR) input, serial (SER) input, and serial outputs for cascading
• When the output-enable (OE) input is high, the outputs are in the high-impedance state
• Both the shift register clock (SRCLK) and storage register clock (RCLK) are positive-edge triggered
• If both clocks are connected together, the shift register always is one clock pulse ahead of the storage register.

ULN2803

• ULN2803APG DIP-18 ULN2803 is high-voltage, high-current Darlington drivers comprised of eight NPN Darlington pairs
• Output current (single output) 500mA MAX

Transitors

• Used as amplifiers or switches
• form factors
  • TO 92
  • 2N3904
  • TO220
• Heat sinks are electrically to heat sink (center lead)

BJT

• Bipolar Junction Transistor
• BJTs are current driven
• NPN most common
  • Apply small current to base
  • Allows high current to flow through collector emitter

MOSFET

• N-channel and P-channel
• 3 leads: gate, drain, source
• N-channel
  • Low voltage applied to the gate
  • Drops resistance between drain and source down to almost zero