I have a 8x8 NeoPixel NeoMatrix connected to a Metro Mini Arduino. It's programmed to display light patterns based on signals from an accelerometer (also in the same circuit). When my arduino is fed power from my computer through the micro usb port, everything works great, but when I try to power the entire circuit with a 9-volt battery, the neopixels frequently freeze up and won't respond to anything, not even the reset button on the arduino.
My guess is that the battery isn't providing enough current for the neopixels, but I would really like to find a way to power them with a battery rather than run a cord to a more powerful source, especially since the device I'm putting the circuit in has very limited real estate.
Any advice or potential solutions?
Thanks!
Powering 8x8 NeoPixel Matrix Issue
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- adafruit_support_bill
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Re: Powering 8x8 NeoPixel Matrix Issue
A 9v battery is not a good choice for several reasons:
1) These batteries don't have much capacity to start with.
2) They have a high internal resistance, so they can't deliver enough current to reliably power 64 Neopixels.
3) The Arduino voltage regulator will need to burn off the excess 4v as heat. Driving 64 pixels to max intensity would require the voltage regulator to dissipate about 15 watts which is enough to make your regulator go up in smoke. Fortunately, your 9v battery can't provide anywhere near that much.
A better approach would be to use something like a 3xAA battery pack with alkaline cells. That would give you 4.5v.
Or you could use a 4xAA battery pack with rechargeable cells. That would give you 4.8v. In either case, you can apply power to the GND and 5v pins (4.5v is close enough for your Metro Mini).
Another option would be to use a 3.7v LiPo cell and a PowerBoost 1000C. https://www.adafruit.com/products/2465
1) These batteries don't have much capacity to start with.
2) They have a high internal resistance, so they can't deliver enough current to reliably power 64 Neopixels.
3) The Arduino voltage regulator will need to burn off the excess 4v as heat. Driving 64 pixels to max intensity would require the voltage regulator to dissipate about 15 watts which is enough to make your regulator go up in smoke. Fortunately, your 9v battery can't provide anywhere near that much.
A better approach would be to use something like a 3xAA battery pack with alkaline cells. That would give you 4.5v.
Or you could use a 4xAA battery pack with rechargeable cells. That would give you 4.8v. In either case, you can apply power to the GND and 5v pins (4.5v is close enough for your Metro Mini).
Another option would be to use a 3.7v LiPo cell and a PowerBoost 1000C. https://www.adafruit.com/products/2465
Please be positive and constructive with your questions and comments.