abuhafss:
Yes, I need the outputs at maximum speed.
How many updates per second? Give us a number.
abuhafss:
Would you please guide me what pins I should use for SHCP, STCP and both DSs for chaining 2 registers for outputs and 1 for LCD.
CONFIGURATION (3)
ARDUINO 595(a) for Outputs 595(b) for Outputs 595(c) for LCD
D9-----------------------------------------------------------------> STCP
D10(SS)-----------> STCP------------------> STCP
D13(SCK)----------> SHCP------------------> SHCP ------------------> SHCP
D11(MOSI)---------> DS---------------------------------------------> DS
Q7* (pin 9)-----------> DS
Note: You must use D13 and D11 as shown if using hardware SPI on atmega328. Other pins could be used instead of D9 and D10, but D10 must be used as an output, so you might as well use it for one of the STCP pins.