nanoFramework Driver for the 74HC595 Shift Register

nanoFramework Driver for the 74HC595 Shift Register

Source Code :https://github.com/Dweaver309/Shift-Register-74HC595/tree/Source_Code

Shift Register Tutorial

74HC595 shift register enables up to 8 additional output ports using only three ports from the device. More ports can be added by "daisy chaining" more chips.

The hardware

• The Q0 to Q7 pins are the new output pins they are in reverse order Q7 is Pin 0 and Q0 is Pin 7
• VCC is connected to 3.3 volts or 5 volts
• Data, Latch, Clock are connected to any three digital pins
• Output Enable is connected to ground
• Master Reset is connected to VCC
• GND is connected to ground

Understanding the software

• The driver is first initialized by calling the constructor like this:

 HC595 ShiftRegister = new HC595(Clock, Data, Latch)

• The pin state is changed by the method SetPin:

 SetPin(Pin,State) Example: ShiftRegister.SetPin(7, false)

1. The SetPin method sets the "Latch" pin low

2. Changes the Bit array to the current state

3. Loops through each bit and sets the data pin high for 1 and low for 0

4. Pulses the Clock pin high and then low to send the data to the shift register

5. After looping though the 8 bits of data the "Latch" pin is pulled high to activate the shift register pins to the current bits state

Contributor: David Weaver