3. What is it?
• A chip
• A shift register
• Allows for extension of Arduino pins
• Can only be used for OUTPUTS
4. How does it work?
• Can be used to control 8 outputs a time using a few pins on Arduino board
• Various chips can be linked, allowing for even more outputs to be controlled
• It is a tristate chip:
• High (on)
• Low (off)
• High Impedance
5. How does it work? Pin Configuration
source: Arduino.cc
6. How does it work? Well, basically...
595 Timing Diagram 595 Logic Table
source: Arduino.cc source: Arduino.cc
7. How does it work? Well, basically...
When the clockPin goes from low to high, the
shift register reads the state of the dataPin. As
the data gets shifted in it is saved in an internal
memory register. When the latchPin goes
from low to high the sent data gets moved from
the shift registers aforementioned memory register
into the output pins, lighting the LEDs.
8. How does it work? Simple Example
source: Arduino.cc
The Essentials:
- blue wire: dataPin
- green wire: latchPin
- yellow wire: clockPin
9. How does it work? Getting Fancy
source: Arduino.cc
Going to second chip:
- blue wire: dataPin extension
- green wire: latchPin extension
- yellow wire: clockPin extension
10. How does it work? Getting Fancy
The "serial output" part of this component comes from its extra
pin which can pass the serial information received from the
microcontroller out again unchanged. This means you can
transmit 16 bits in a row (2 bytes) and the first 8 will flow
through the first register into the second register and be
expressed there.
11. Our stab at it
•
AIM: Create a temperature visualize
HOW?
• Measure current temperature using a thermistor
• Divide full temperature range into into three brackets
• Each bracket = one PISO
• Attach LEDs to each chip
• As more of the brackets are covered, more LEDs light up
• LEDs change color as new brackets are reached
