Control Surface master
MIDI Control Surface library for Arduino


This example demonstrates the use of shift registers as if they were just normal IO pins. The SPI interface is used because it's easy and fast.

AVR, AVR USB, Nano Every, Nano 33 IoT, Nano 33 BLE, Due, Teensy 3.x, ESP8266, ESP32


Connect an LED (and series resistor) between the first output of the shift register and ground.

Remember to connect the enable pin of the shift register to ground and the master reset pin to Vcc in order to enable it.


This sketch will blink the LED once a second.

Written by PieterP, 2018-09-01

#include <Arduino_Helpers.h> // Include the Arduino Helpers library.
using namespace ExtIO; // Bring the ExtIO pin functions into your sketch
// Instantiate a shift register with the SPI slave select pin as latch pin, most
// significant bit first, and a total of 8 outputs.
SPIShiftRegisterOut<8> sreg {SPI, SS, MSBFIRST};
const pin_t ledPin =; // first pin of the shift register
void setup() {
sreg.begin(); // Initialize the shift registers
pinMode(ledPin, OUTPUT); // You don't even need this line, since
// shift registers are always outputs
void loop() {
// Toggle the state of the LED every 1/2 second
digitalWrite(ledPin, HIGH);
digitalWrite(ledPin, LOW);
constexpr PinStatus_t LOW
constexpr PinStatus_t HIGH
constexpr PinMode_t OUTPUT
Dummy header file for Arduino builder.
void pinMode(pin_t pin, PinMode_t mode)
An ExtIO version of the Arduino function.
void digitalWrite(pin_t pin, PinStatus_t val)
An ExtIO version of the Arduino function.
uint16_t pin_t
The type for Arduino pins (and ExtendedIOElement pins).