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Simulated Time and Day of Week from Arduino


Arduino's are very common microcontroller boards used to study and design programmable electronics. It is often used with multiple peripherals such as buttons, sliders, sensors and motors.

Together with a TIMI acting as a small fancy display, Arduino boards become a lot more powerful and interesting to use in prototyping.

This project showcases a TIMI-96 module controlled by an Arduino Uno to output simulated day of week and time of day values.


To proceed with the project, the following are required.


  • TIMI-96
  • Mates Programmer
  • USB Type A to microUSB cable (for the Mates Programmer)
  • USB Type A to Type B cable (for the Arduino, replace as necessary)
  • Connecting Wires
  • Arduino Uno
  • Breadboard


Graphics Design

Step 1: Open Mates Studio and create a Commander project for TIMI-96 with Reversed Landscape orientation


Select Commander

Step 2: Browse the library for appropriate page designs. For this project, Digital Clock page under Date and Time category was used.

Browse Library

Digital Clock

Step 3: After finalizing the design, connect TIMI-96 to your computer

Connect TIMI-96

Step 4: Upload the project to the appropriate COM port

Select Port

Project Upload

Step 5: When prompted, click Proceed to continue with upload.

Date and Time Proceed


It is recommended that the graphics design is finalized before moving to the next steps when working on a project

Programming the Arduino

Step 1: Install the MatesController library using Arduino’s Library Manager.

Library Manager

Step 2: Include MatesController.h to your project

#include "MatesController.h"

Step 3: Create a MatesController instance named mates.

MatesController mates = MatesController(Serial);

This will initialize the MatesController instance to the default reset pin 4 using a LOW pulse.

Step 4: (Optional) Create a function for toggling the built-in LED of the Arduino board. This can be used for debugging or showing errors if the Serial monitor can’t be used.

int errLedStatus = LOW;
void ErrorLed_Toggle() {
  errLedStatus = ~errLedStatus;
  digitalWrite(LED_BUILTIN, errLedStatus);

Step 5: (Optional) At the beginning of the setup function, set the built-in LED pin to OUTPUT and set it to LOW.

digitalWrite(LED_BUILTIN, errLedStatus);

Step 6: To start using the MatesController instance, use the begin function


Step 7: (Optional) The begin function can be enclosed in an if condition to handle initialization errors.

if (!mates.begin()) {
  // Display didn't send ready signal in time
  while (1) {

Step 8: To print the day of week, an array of strings needs to be prepared.

// Days of Week Strings
const char * daysOfWeek[] = {

Step 9: Integer variables for day of week, time and a few other variables are also required to store and simulate values.

// Simulated Timer Variable
unsigned long lastUpdate;

// Test Start Values: Monday, 23:59:47 (will actually start at 48 seconds)
uint8_t lastDay = 1;
uint8_t dy = 1;
int16_t hr = 23;
int16_t mn = 59;
int16_t sc = 47;

Step 10: In the loop function, the values are simulated and sent to TIMI as necessary.

void loop() {
  if (millis() - lastUpdate >= 1000) {

    lastUpdate = millis();

    if (sc == 60) {
      sc = 0;
    if (mn == 60) {
      mn = 0;
    if (hr == 24) {
      hr = 0;
    dy %= 7;

    // mates.setWidgetValue(MATES_LED_DIGITS, 0, hr);
    // mates.setWidgetValue(MATES_LED_DIGITS, 1, mn);
    // mates.setWidgetValue(MATES_LED_DIGITS, 2, sc);
    mates.setLedDigitsValue(0, hr);
    mates.setLedDigitsValue(1, mn);
    mates.setLedDigitsValue(2, sc);

    if (lastDay != dy) {
      mates.updateTextArea(0, daysOfWeek[dy]);
      lastDay = dy; // prevents writing the same text to TextArea


As shown, the simulated values utilizes a second non-blocking delay to simulate a second increment in time. The minutes, hours and day of week are updated accordingly.

Step 11: Lastly, to ensure that the day and time values are written to TIMI for the first loop, the lastUpdate variable should be set to 1s behind at the end of the setup function.

void setup() {
  digitalWrite(LED_BUILTIN, errLedStatus);

  if (!mates.begin()) {
    // Display didn't send ready signal in time
    while (1) {

  lastUpdate = millis() - 1000; // Ensures first write

Running the Project

After designing the user interface for TIMI and writing code for the Arduino and programming them, it is time to connect the devices together. Follow the diagram below for the connection between TIMI and Arduino.

Arduino TIMI Day and Time

Finally, supply power to the Arduino and observe the behavior of the project.

Downloadable Resources

The Mates Studio – Commander project and Arduino sketch are included in the MatesController library.

The Commander project is available under the extras folder of the library. You can find it in (if the library was installed using Arduino Library Manager):

C:\Users\%USERNAME%\Documents\Arduino\libraries\MatesController\extras\Day and Time.mates

Here are the links to the software applications, libraries and completed project files.