Trinket and LED Arcade Buttons

[jgreen624]

Hi all, pretty new to Adafruit and this type of creating in general, so my apologies if this question is pedestrian.

I bought a Picade kit and am loving it, but would like to change out the kit buttons with LED illuminated ones from the Adafruit shop. I read on Sandy McDonald's review of the Picade that she used the Trinket to power them. I'm very much an amateur and newbie at electronics, voltage, wiring, etc. so I just wanted to ask directly instead of guessing: if I want to power 6 of the LED buttons and they require 5v, how many Trinkets do I need? Same question but for 12 buttons as well.

Adafruit shop links for reference:
https://www.adafruit.com/product/1501
https://www.adafruit.com/product/3490

[adafruit_support_mike]

The Trinket can control three LEDs without any trouble, and two more if you're careful with the hardware connections.

A Metro Mini would probably be a better fit for you though:

https://www.adafruit.com/product/2590

It has 12 pins that can control LEDs without any problems, and is functionally identical to the Arduino Uno. The Uno is a good place to start working with microcontrollers, and has a ton of support. We even have a series of tutorials that can help you get started:

https://learn.adafruit.com/adafruit-ard ... on-1-blink

Aside from being easier to work with, the Metro Mini will be smaller and cost less than the number of Trinkets you'd need.

[jgreen624]

Thank you so much for the information and my apologies for such a delayed response.

Does Adafruit sell the power adapter that would power the metro mini?

[adafruit_support_mike]

Sure.. there are lots of options. You might not need a separate power supply though.

If you're still working with the PiCade you can run a small USB cable from the RasPi to the Metro Mini's USB jack, or make a connection from the RasPi's 5V and GND pins to the Metro Mini's 5V and GND pins.

If you do want an external power supply, any 5V phone charger with a micro-USB plug should work:

https://www.adafruit.com/category/581

You can use a 4-pack of AAs connected to the Metro Mini's Vin and GND pins, or a 3.7V LiPo connected to the Metro Mini's 3.3V and GND pins.

If you want to use the LiPo option, flip the Metro Mini over and use the solder jumpers to change its connections from 5V logic to 3V logic. Just cut the trace connecting the center pad to the pad labeled 5V, and use a blob of solder to connect the center pad to the one labeled 3V.

[jgreen624]

You all are the best, thanks so much for responding!

Last question: so do you think the metro mini and LEDS will still have plenty of power if I just use USB from the Pi 3?

[adafruit_support_mike]

Yeah, that will work.

The Pi3's USB ports can put out 500mA @ 5V. The Metro Mini uses about 50mA at most by itself, and the microcontroller is limited to 200mA total.

If you send 12mA ot 13mA through a dozen LEDs, that will add up to about 150mA.. enough for the LEDs to be bright, within the microcontroller's limits, and well within the USB port's current limit.

[jgreen624]

Thank you kindly. I learned a lot just from this thread, and I appreciate the assistance. You guys are the best.

[adafruit_support_mike]

Happy hacking!