ESP8266 Community Forum

- Mon Jun 13, 2016 2:19 pm #49140 Hi there,

I'm new to this and might ask stupid questions. I've got a couple of these boards:
http://www.aliexpress.com/item/NodeMcu- ... 97795.html

I want to use one of them as a night light under the bed (motion activated). So I wondered a) which LEDs to chose and b) how to connect them.

I don't have specs for this board so I have no idea about the real data, but I read that the GPIO pins usually have max 12ma current. Is this right? Would you go for standard 3.3V LEDs and just add a single LED to a couple of GPIOs in order to cover as much as possible? Or should I go for specific LEDs?

I couldn't find too many bright ones under 20ma so I would appreciate any kind of input..

Thanks a lot,
Christoph

- Tue Jun 14, 2016 4:50 pm #49195 According to Espressif the max current is indeed 12mA but that is per GPIO so you could drive as many LEDs as you like. Whether you can connect them all to the same LED I don't know but the total max current is 16x12mA.

- Tue Jun 14, 2016 4:58 pm #49196 I should have pointed out that this is the maximum source current. The maximum sink current is 20mA per GPIO.

- Tue Jun 14, 2016 6:33 pm #49201 If you need more current, you can always use a transistor to switch the LEDs. A NDP6020P for example will allow you to switch more than 20A with a single GPIO, more than enough to burn your eyeballs out of their sockets ;)

Regarding your choice of LEDs: that depends on what you want to do with them and how much light you need.
Standard "super bright" 5mm LEDs should more than suffice for a night light.
If you want something more fancy, there are individually adressable RBG LEDs like WS2812b (or SK6812 which also comes as RGBW or white variants).