Particle Argon and Neopixels


i have been using the particle photon for a long time along with the neo pixels led strip. I usually use less than 5 led’s, so i get away simply using the 3v3, without using any 3 -> 5 Volts level shifter.

I tried using the argon with the neo pixel yesterday and it didnt work. Initially it gave libraries issues, but i upgraded the library for the neopixel and that took care of that error. But beyond that, although i dont get errors, but the neopixels dont work. Nothing lights up. My confusion was that is an level shifter absolutely necessary for the Particle Argon? If yes, how do the neo pixels manage to work with the Particle Photon? Or is there some issue with the neo pixel library?

Thanks in advance :slight_smile:


Like yourself I’ve been running neo pixels on the Photon without level shifters to drive the data line.

Typical config:
Neo +V to Photon Vin (which is 5v via the USB)
Neo -V to Photon Gnd
Neo Data to Photon D4 (which is just my choice, and D pin should do, avoid D7 as it has an LED)

So my question is whats your config. The Argon VUSB pin, is only output 5V when the Argon is connected to the USB, its not got anything when running off the Lipo.

(Still waiting to play with my Argon, as I can not set them up via BT.)


Thanks for your reply.

I am using a 3.7V lipo, so i dont have the luxury of getting any 5 Volts.

Neo +V to Photon 3V3
Neo -V to Photon Gnd
Neo Data to Photon: For this i tried several different pins but with no luck

My confusion arrises from the fact that i use the same config on my Photon and it works, but with argon it does not.


Have you tried using a multi meter to check the output voltage of the Argon 3.3V is infact 3.3V and it might be worth checking the voltage of your chosen data pin. Although its will not be 3.3V DC it should read pretty close on a DVM, check with a scope if you can.

There have be other discussions on this matter

And it looks like people cracked it. So other issues could be;

  1. Not all neo pixels are the same, some are more forgiving in pushing their limits than others. Try a different brand.

  2. Are you using a capacitor on the neo pixel DC in? You should be able to live without for just a few neopixels.

  3. Are you using a resistor on the data line. You can often live without it.


Thanks again for your reply.

Yeah, i used that post to update the library.

Unfortunately, i dont have any scope but used the DVM to get measure the Voltage at the D4 pin after uploading the Pin and am getting 0 V.

To be honest, i am not too happy with the Argon boards, it takes almost ever to upload your code. It took 5 unsuccessful tries, before i could finally get the code downloaded on the board, and even after that it seems not to be working.

I have another Argon that i was setting up today and its been sitting for the past 1 hour loading something.

  1. I already verified, the led’s work on the photon
  2. No, is this supposed to smooth the input volage?
  3. No

Moreover, just for curosity, how is the data sent over the Data pin? What protocol does it use?

Thanks Again!

So my Second Argon finally got setup, and the neo pixel seems to be working with it.

I guess something is wrong with the other Argon that i have.


Update on the checking for signal presence on the data pin using a DVM.

I quickly checked a photon that I am soak testing using a 60 neopixel ring as a clock. I managed to read only 0.04V on the data line and 0.00V when I took the probe off. Its quick and dirty way to suggest that I have a signal present, but it was lower than I expected… Which is dependent on the sample rate of the DVM, and if the data line is normally high or low… But it tells me something is going on, on my line. But a scope would be a MUCH better indicator, and a differnet make model DVM will give a different result. Remember we are not actually making a measurement, per say… Just detecting a signal presence.

As for the protocal, I think its pretty unique to neo pixels, and is based on a high/low switch of the data line. That why timing is critical with neo pixels. There are data sheets out there… but its such a pain to read… 99.99% of people rely on the libs.

The whole mesh enviroment has, I think, been a bit more bleeding edge, than I think the people at Particle had hoped for. Which I think is a shame, but I think will be worth going through the learning curve for. The Particle people I know REALLY want this to come together, and considering the core to photon evolution I belive the Particle team will get there.

I’m sitting on my hands with mine, which is a huge shame as I ordered mine the moment I got the announcement. For me the problem is the BLE set up, which requires you having the right smart phone/tablet in the first place. I’m sick of smart phones and tablets. In particular the fact that with so many android variations, its impossible to develop for everyone. Apple have closed in their platform. But Apple treat their customers like whipping boys, and if I’m going to be treated like, that the person wielding the whip must have a sweeter smile on their faces, and a devlish twinkle in their eye…:wink:

Once a USB setup option become available I’ll be in there like Flin.

Sorry I can not be any more help.