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{{asm-text}} For many wearable projects we recommend a lithium-polymer battery. These deliver 3.7 Volts — perfect for directly feeding low-power microcontrollers such as the Adafruit Flora, yet enough voltage to run a short length of NeoPixels.
{{asm-text}} {{bloc-etroit|text=For many wearable projects we recommend a lithium-polymer battery. These deliver 3.7 Volts — perfect for directly feeding low-power microcontrollers such as the Adafruit Flora, yet enough voltage to run a short length of NeoPixels.}}
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'''Battery-operated LED project planning is discussed in greater detail in [[Piles et accus pour alimenter les NéoPixels|Piles et accus pour alimenter les LEDs et Rubans NéoPixels.]]'''
'''Battery-operated LED project planning is discussed in greater detail in [[Piles et accus pour alimenter les NéoPixels|Piles et accus pour alimenter les LEDs et Rubans NéoPixels.]]'''
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{{asm-text}} For most non-portable “desktop” projects, a 5V DC switching power supply is ideal. This small 2 Amp supply is good for a a meter or so of NeoPixel strip. We’ll explain larger projects in a moment.
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{{asm-text}} '''Be extremely cautious with bench power supplies.'''
Some — even reputable, well-regarded brands — can produce a large voltage spike when initially switched on, instantly destroying your NeoPixels!
If you use a bench supply, do not connect NeoPixels directly. Turn on the power supply first, let the voltage stabilize, then connect the pixels (GND first).
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== Estimation de la puissance nécessaire ==
Each individual NeoPixel draws up to 60 milliamps at maximum brightness white (red + green + blue). In actual use though, it’s rare for all pixels to be turned on that way. When mixing colors and displaying animations, the current draw will be much less. It’s impossible to estimate a single number for all circumstances, but we’ve been using 1/3 this (20 mA per pixel) as a gross rule of thumb with no ill effects. But if you know for a fact that you need every pixel on at maximum brightness, use the full 60 mA figure.
To estimate power supply needs, multiply the number of pixels by 20, then divide the result by 1,000 for the “rule of thumb” power supply rating in Amps. Or use 60 (instead of 20) if you want to guarantee an absolute margin of safety for all situations. For example:
* 60 NeoPixels × 20 mA ÷ 1,000 = 1.2 Amps minimum
* 60 NeoPixels × 60 mA ÷ 1,000 = 3.6 Amps minimum
The choice of "overhead" in your power supply is up to you. Maximum safety and reliability are achieved with a more generously-sized power supply, and this is what we recommend. Most power supplies can briefly push a little extra current <font style="text-decoration: underline">for short periods</font>. Many contain a thermal fuse and will simply shut down if overworked. So they may technically work, but this is the electronics equivalent of abusing a rental car.
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