Hi there!
Im making an automated greenhouse for a school project and I need to turn on 100 leds (DIY Grow Lights). All of the leds need to be turned on at the same time. how can I make this posible?
An arduino leonardo can power all the leds?
Do i need any extra circuitry?
Thanks!
PD.: we want to use "normal" leds as we are using peltier modules to produce heat on the greenhouse
Are these individual 20ma T1 3/4 LEDs ?
If so, what DC voltage/current is available.
An arduino leonardo can power all the leds?
A normal Arduino like Leonardo can supply 20~40mA per pin and around 200mA in total. Your leds will need ten times that much. Assuming 20mA each (you don't say much about the LEDs), that's 2,000mA. So you will need a driver, yes. If you have a relay module already, you could use that. Otherwise I would recommend an n-channel power-MOSFET with a logic-level gate such as stp16nf32l (there are many other suitable models). If you want to dim the leds, rather than just on/off, then the MOSFET is the way to go. Your power supply will need to be at least 2.5A but may be able to power the Leonardo as well as the LEDs. But don't route all that current through the Leonardo. Use separate power cable from the power supply to the LEDs.
Thanks Paul & larryd for answering. I'll go for the relay module as i already own one.