This library drives the Technoshield User Interface board (https://github.com/jscastonguay/technoshield-ui-hw). It is based on two libraries devepped by Adafruit which are

• Adafruit LiquidCrystal
• Adafruit MCP23008 library

Both are already included in the Technoshield User Interface SW Library. See the following link for further details: Technoshield Hackaday project

Follow this instruction and look for technoshield.

Start by first create a user interface (ui) instance as follows:

Technoshield_ui ui(JUMPER_OPEN, JUMPER_OPEN, JUMPER_OPEN, JUMPER_OPEN);

where each parameter can be either JUMPER_OPEN or JUMPER_CLOSE. The parameters correspond to the state of I2C Addr jumpers located on the Technoshield board following the same order from left to right:

1. LCD A1
2. LCD A0
3. Button/LED A1
4. Button/LED A0

These jumpers are used to change the I2C addresses of the LCD and buttons/LED which are

Note that the creation can be done also as follows:

Technoshield_ui ui(0, 0);

where the parameters correspond to the I2C subaddresses (0 to 3) made by the jumers' states. Installing a jumper sets VCC to the corresponding subaddress pins. So, the subaddress is 0 if both LCD A1 and LCD A0 are opened, is 1 if LCD A1 is opened but LCD A0 closed, and so on.

Finally, if all jumpers' states are open (meaning 0 as I2C subaddress for both LCD and Buttons/LED), the following can be used:

Technoshield_ui ui;

After the user interface object has been created, it must be initialised in the setup function as follows:

void setup() {
  ui.begin();
}

Almost all functions of the standard Arduino Liquid Crystal library are supported. For examples:

 ui.print("hello, world!");
 ui.setCursor(0, 1);
 ui.setBacklight(true);

See the LiquidCrystal library for further details.

For SD card usage, use the standard SD library. Note that the SD card Slave Select is connected to the Arduino's pin 10. See the SD Library for further details.

The following functions can be used to drive the buttons and the LED.

isButtonPressed(button)

This function returns true if a given button is pressed. button is from 1 (the button named SW1) to 5 (the button named SW5).

setLedState(led, state)

This function turns on and off a given LED. LED is from 1 (the LED named D1) to 3 (the LED named D3). The state can be 0, 1, false, true, LOW, HIGH, etc.

Here is a basic example. The buttons 1 to 3 (SW1 to SW3) turn on one of LED, the button 4 (SW4) turn on the LCD backlight while the button 5 (SW5) turn off the LED and the backlight. Note that in this example all I2C Addr jumpers are opened.

#include <Technoshield_ui.h>

Technoshield_ui ui(JUMPER_OPEN, JUMPER_OPEN, JUMPER_OPEN, JUMPER_OPEN);

unsigned long timeout = 0;

void setup() {
  ui.begin();
  ui.print("hello, world!");
}

void loop() {

  // Print the number of seconds since reset:
  if (millis() > timeout + 1000) {
    timeout = millis();
    ui.setCursor(0, 1);
    ui.print(millis() / 1000);
  }

  // Turn-on LED or backlight according to buttons 1 to 4.
  if (ui.isButtonPressed(1)) {
    ui.setLedState(1, true);
  }

  if (ui.isButtonPressed(2)) {
    ui.setLedState(2, true);
  }

  if (ui.isButtonPressed(3)) {
    ui.setLedState(3, true);
  }

  if (ui.isButtonPressed(4)) {
    ui.setBacklight(true);
  }

  // Turn-off everything.
  if (ui.isButtonPressed(5)) {
    for (int i = 1; i <= NB_OF_LED; i++) {
      ui.setLedState(i, false);
    }
    ui.setBacklight(false);
  }
}