So I’m embarking on a big project (at least for me). I’ve created a matrix of LEDS 38x19 = 722 pixels. This is a wearable project so I set the brightness level to 35% or less so I don’t burn people’s eye out when wearing it.
I’m using it to display sprites which bounce around the matrix - so very few of the pixels are lit at the same time. But this last sprite, as shown in the picture, makes my Teensy 3.2 lock up because I believe its drawing too much power for that controller. I have one of those Charger Doctor power meters from Adafruit and it says its drawing about .58A. The LEDS are connected the the controller’s +/- output. The controller is currently being powered via the USB port but will be powered by a lipoly battery 2500mah.
So I was thinking about connecting one lipoly to the LEDS positive and ground. And powering the controller by another lipoly. I believe the ground needs to be connected between the LEDS and the controller if I do that. Is that correct? Dangerous? I’m afraid of the batteries discharging into each other and possibly exploding. That would be very bad for my head.
Probably good practice to not power that many pixels through the MCU’s pins. Always try to directly connect to your LEDs to the power source.
You can use two batteries, just make sure the grounds of everything are connected together. And that at the positives of the two batteries are Not connected together anywhere. You could also use a single battery to keep it simple to start with and add a second later if you need more. And while testing/coding you could power the MCU via USB and power the LEDs via battery, just have a common ground between them.
Just remember that if you’re going to power the Teensy by battery (external source) AND plug in the USB cable you need to cut that little power trace on the bottom (as noted on the backside of the “Welcome to Teensy” reference card).
Thank you for the response. I don’t plan on powering with both USB and Battery, but it might be smart to cut that trace anyways.
I do NOT have one currently, but that’s a good idea. I’m presently feeding power and ground into both ends of the matrix, so I’ll put the capacitor at the battery connection.
Power/electricity is my weakest knowledge point so if you have any good books or sites to read, I’d appreciate it. I’ve watched a bunch of Youtube videos but still feel like I don’t know enough.
