Timed Light for Fish Tank

Everyone Questions and Answers
1

hi guys, im new here! :slight_smile: I still dont really understand watts, amps, or voltage, but I wanted to start a small project for my fishtank.

I want the light to turn on for eight hours a day, and turn off for sixteen hours. Simple right?

The cable for the light had a switch in it, but I removed the plastic case and switch, exposing the wire (see picture). I’ll share the cable specs at the bottom.

I want to use an Arduino Nano to program the timer, and I am thinking about eventually adding a 1-digit 7-segment display to show how many hours remain until the light switches on or off.

I can handle the programming, but does anyone have any suggestions for the wiring part? Will I need relays.. or resistors? How should I go about making the “schematic”? How do I keep all the amps and volts and whatever compatible?

I am open to reading/watching any resources you can recommend. I have background in coding and I played with Arduino as a kid, but I didn’t do much past the blink experiment. I would love to learn more about electronics because there is so much to do!

Please let me know if I can answer any questions. Thank you so much for any help, I appreciate it!

Specifications:

Elegoo Nano Unsoldered OR Lavfin Nano Soldered (both are Arduino Nano equivalent)

5611AH 1-digit 7-segment display

Power Cable (see pictures)

IMG_0662
IMG_06621920Ă—2560 634 KB

2

I could only add one picture. Here is the wire for the power supply.

IMG_0664
IMG_06641920Ă—2560 587 KB

3

Start with the simplest “schematic capture” - just draw it out using pen and paper.

Avoid pictorial diagrams, try to keep it in symbolic format.

There are a few more details to add-

What is the voltage and wattage of the light?

How much timing innacuracy can you tolerate? An Arduino has a crystal oscillator, but it’s not terribly accurate for timekeeping purposes, it will drift over time.

I for simplicity, I would suggest you buy a solid-state relay to control the light, it’s simple to interface these to your Arduino.

Post your drawing here- we can help guide you along the way.

4

relay
relay965Ă—630 69.7 KB

A really simple way to control an AC load from Arduino…