Arduino LED Timer

Visually displaying kids the reaming time before we have to leave the house is the goal of this project.

A simple RGB LED strip is used for displaying the timeline. It starts with a fully lit strip, where the top LEDs are green, the middle LEDs are yellow and the bottom LEDs are red. As time passes the LEDs will go off from top to bottom. Finally, when time is up, the whole strip flashes red for some time.

The boards wifi capabilities are used to retrieve the current time from a time server (via NTP). This time is then provided to the boards real-time clock (RTC). The time server is queried regularly to update the boards RTC.

The on-board LED matrix is used to display the current time (hours and minutes).

Required Equipment

• Arduino Uni R4 WIFI
• WS2812B RGB LED Strip - 1m 144 LEDs in this case
• Power Supply DC 5V ~8A, e.g. Mean Well LPV-60-5
• Jump wires to connect Arduino to LED strip
• Arduino IDE for programming

Third Party Software

Inspirations for this project were found on the website from Hartmut Waller.

This project uses the following third party projects:

• NTP: https://github.com/arduino-libraries/NTPClient/
• FastLED: https://fastled.io/docs/index.html
• RTC: https://docs.arduino.cc/tutorials/uno-r4-wifi/rtc/
• Logger: https://github.com/thijse/Arduino-Log/

Configuration

Many aspects can be configured. Each aspect has its own config file.

LED Config

This project uses FAST LED.

Configuration is done in the LedStripConfig.h file.

Use TIMER_LEDS, to configure the number of LEDs in the strip.

Timer Config

Use the TimerConfig.h file to set-up your timers.

Each timer must be provided as a time range, using two instances of RTCTime. Notice, RTCTime contains more information than needed. Only the day-of-week, hour, minute and second are relevant.

So, if you like to have a timer starting every Monday on 7:05am and ends 7:35am, set it up like this:

// RTCTime(day, month, year, hours, minutes, seconds, DayOfWeek, SaveLight)
{
  RTCTime(0, Month::JANUARY, 0, 7, 5, 0, DayOfWeek::MONDAY, SaveLight::SAVING_TIME_INACTIVE),
  RTCTime(0, Month::JANUARY, 0, 7, 35, 0, DayOfWeek::MONDAY, SaveLight::SAVING_TIME_INACTIVE)
}

WiFi Config

The WiFi credentials are configured in the WifiConfig.h file.

Please ensure it is used in the projects .ino file: #include "WifiConfig.h"

Flash Config

The LedFlashConfig.h can be used to:

• Disable the flash-mode
• Define time in milliseconds for on and off state
• Define the total duration the flash-mode is active
• Alternatively, define the number of flash cycles

Timezone Config

See the initNtpClient function to configure the date and time for changes between summer and winter time.

E.g. for Germany:

  // CEST: Central European Summertime GMT + 120mins
  ntp.ruleDST("CEST", Last, Sun, Mar, 2, 120);

  // CET: Central European Time GMT + 60mins
  ntp.ruleSTD("CET", Last, Sun, Oct, 3, 60);

Development

If connection to the board fails, it could be due to missing permissions. You can temporarily permit yourself via: sudo chmod a+rw /dev/ttyACM0