Meeting 16 – 4/15/16

Chapter 7: Shift Registers • With shift registers, you can expand the

I/O capabilities of your Arduino without having to pay a whole lot more for a more expensive microcontroller with additional I/O pins.

• A shift register is a device that accepts a stream of serial bits and simultaneously outputs the values of those bits onto parallel I/O pins. Most often, these are used for controlling large numbers of LEDs

Chapter 7: Shift Registers • The eight circles represent LEDs connected to the eight outputs

of the shift• register. Pins Q_A through Q H_

• The three inputs are the serial communication lines that connect the shift register to the Arduino.

• VCC will connect to 5V.

• GND will connect to a shared ground with the Arduino.

• The SER pin (DATA) will feed in 8 sequential bit values to set the values of the parallel outputs.

• The SRCLK pin (CLOCK) every time this pin goes high, the values in the shift register shift by 1 bit.

• The RCLK pin (LATCH) allows you to sequentially shift data into the chip and have all the values show up on the parallel outputs at the same time.

Shift Registers • Every time the clock signal

transitions from low to high, all the values currently stored in the eight output registers are shifted over one position.

• By doing this eight times, the present values are shifted out and the new values are shifted into the register.

• The LATCH pin is set high at the end of this cycle to make the newly shifted values appear on the outputs.

Shift Registers

• Creating light rider animation with increasing/decreasing decimal sequence in a loop as opposed to default static binary setting.

Shift Registers

• Possible other pattern designs?

• Change up the colors?

• Why powers of 2?

• Replace line shiftOut(SER, CLK, MSBFIRST, 170);

For next time... (4/22) • Read Chapter 7

• up to pg 156

• Pulse Sensor (finally!) here

• For next year...?