Can I hook up my neopixels directly to my photon and power them that way if its on usb power.
I have seen all kinds of hookups, some say you cant, some say you can, others have 3.3v to 5 on the neopixel etc.
Can anyone verify I can hook up two or even one neopixel ring to the photon and power like so
VIN -> power of neo
GND - Photon gnd
Data pin - > D6
Yes you can.
The Particle Internet Button has eleven NeoPixels directly connected.
Your wiring should be fine, but you can also have a look at the PIB schematics
great thanks. I kept reading all about this 3.3 -> 5v level shifting stuff. I have the shield shield from particle but no idea how to use it yet.
I saw the internet button that just made me more confused with the 3.3 -> 5 level stuff.
Anyway long story short it should work, thanks for the help
One thing to consider still is the max current your NeoPixels will draw.
@Keaner, @ScruffR is right about the total current. At 60ma max per neopixel (full brightness white), you will need 720ma for 12 of them or 1440ma for two rings. I suggest you use a GOOD 2A USB supply if you want to do that. The Photon’s onboard protection diode going from Vusb to Vin can handle 3A so you should be ok there.
yeah i have that part figured . I know they will draw at east 18ma per up to 60. I do usually power them with a separate power supply but , for testing a few I was hoping i could just wire it to photon directly, which I can / did. Works good enough for testing.
I keep running into this 3.3 problem as I’m so used to the 5 volt Arduino. All my sensors are 5 volt as well, thermistors etc. I think ill drop my photon into the shield shield i got for it and then i can ignore most of this 3.3 to 5v magic stuff lol.
Thanks for all the tips so far
Quite a few 5V devices will work with the Photon without the shield shield because most of the digital inputs on the Photon are 5V tolerant. For example:
I2C - No problem running at 5V. Note that the Photon does not have built-in pull up resistors for I2C so you may need to add external pull-ups to 5V (often 4.7K or 10K), on both SDA and SCL.
SPI - As long as the SPI device you are controlling doesn’t mind 3.3V for logic 1, it’s safe to power the SPI device at 5V and it won’t damage the Photon.
Serial - Same with TTL serial. As long as the TTL serial device doesn’t mind 3.3V for logic 1, it won’t damage the Photon if it sends 5V for logic 1 into the RX pin of the Photon.
And the same for the GPIO digital input and output pins.
The main thing is that you can’t put a 5V signal on an analog input (ADC) pin in analog input mode. Also, you can’t use an internal pull-up or pull-down resistor, such as pinMode(D2, INPUT_PULLUP) with 5V digital signals on the Photon.
ahhh ok, good to know. I’ve printed off your response here to burn it into my brain.